Resined slabs: The Good, The Bad and The Ugly
by Frederick M. Hueston, Stone World Technical Editor
Q: Our shop has been getting a lot of resined slabs lately, and I am a little confused as to why slabs are resined to begin with. I would be interested to know why they are resined and what problems fabricators are having with these resined slabs?A: In the past few years, I have had many fabricators ask the same question. Of all the fabricators I have spoken with, some have no problem at all with resined slabs, while others are having nothing but problems. The following are some of the pros and cons of resined slabs. The following article is not intended to solve this problem or to render an opinion but to put forth arguments from both sides. In other words the good, the bad and the ugly.
The resining of stone slabs is not as new as some might think. Resining started back in the 1960s on marble and about 10 years ago with granite. Today, the resining of slabs is commonplace, and it is predicted that almost all stone slabs will soon be resined.
What is resining? The resining process uses epoxy resins for granites and polyesters for marble. There are several methods that are used to apply and cure the resin, from hand-spray applications to automated lines. The slabs are first honed and dried, and then the resin is applied. The slabs are then cured in heated ovens, and after the resin is cured, the slabs are sent to the polishing lines where they are polished. Some factories also apply a thin layer of wax to the surface after polishing to help protect the stone during shipping.
The Good The resining of slabs has allowed slab producers to eliminate lots of waste and sell slabs that would otherwise be rejected. Brittle materials can now be used due to the resining process, which helps hold the brittle material together like a glue.
Resined slabs are also less likely to become damaged during shipping.
Resining of slabs has also reduced the price of slabs, which is one reason the industry is seeing such a big growth in slab sales in recent years.
Resined slabs are also less porous, and many resined materials do not need to be sealed, since the resin acts as a sealer for the stone.
In addition, Filippo Emanuel of Tenax USA listed the following benefits in a recent article in Stone World (June 2003, page 100):
Several materials are naturally fractured and could not otherwise be sold or marketed even if they are superior in terms of color, durability and other qualities.
There is a growing tendency in producing thinner slabs to reduce transportation costs and open up new markets and different stone uses.
The waste from manufacturing slabs of particular materials (especially some marbles) could represent 35 to 40% of production, thus considerably increasing the cost of the remaining slabs.
Many different kinds of granites have natural micro-fissures that compromise the final polished effect, thus reducing the beauty of the material.
There are materials just too fragile to be polished, leaving no solution but to close down quarries.
Some granites have fissures that pass through the slab and considerably decrease the strength of the slabs and pose a hazard when used as outside paneling.
Limited reserves of a particular color of stone leave only the worst and more damaged veins to be quarried.
The Bad and The Ugly Over the past few years, several problems have arisen with resining slabs. The following are some of the problems that have been encountered:
1. FadingOne of the major complaints associated with some resined slabs is that the resins used are not UV resistant. I have heard of several fabricators who store their slabs outside for several months, and when they go to use them, they discover that the slabs have darkened. This is especially true of slabs that are covered. In one case, a slab of stone was partially covered with another section of stone. When that small section was removed, it was discovered that the portion of the slab that was not covered had darkened. This is the result of UV light reacting with the resin. The lesson to be learned here is not to store slabs outdoors in direct sunlight. This is especially true of light colored materials such as Giallo Veneziano and others.
However, Emanuel points out that there should be no resin on the surface of the slab. “If there is, it means that the manufacturer did not do a good job removing it,” he said. “That is when fabricators start having problems with darkening effects.” If done correctly, the resin is inside the cracks and the pits, but nowhere else.
An additional problem is with profiles. Several fabricators have had experiences with the profiled edge turning out lighter than the rest of the stone. “The problem with the edges is that the resin will darken the top of the slabs regardless of the UV,” Emanuel explained. “It is just the effect of the different reflection of the light when a material is imbibed with resin. When you cut the edge, there is no resin on the side — regardless of the UV exposure. That’s the reason why the edges are lighter.”
Over time, we have found that the edge will darken and match the face of the stone. A quick fix to this problem is to use a color enhancer to darken the edge.
2. Sealer interactionOur technical hotline has received several calls where impregnators have been applied to a resined stone, and the material clouds, discolors or fades. After testing several slabs and sealers, I have discovered that some solvent-based impregnators will react with the resin, causing it to break down and turn color, cloud or fade. This is a problem that is difficult to repair. We have found that the application of a color enhancer will sometimes hide this problem. My recommendation would be to use only water-based impregnators on resined slabs.
3. Polishing and refinishing problemsIn a recent countertop repair seminar, one of our students brought in a resined section of stone he wanted to try and refinish and polish. We discovered that this material had such a heavy application of resin that when he tried honing the top, the resin became gummy. Once the surface was cut and polished, it was very difficult to match the remaining surface of the stone. As of this writing, I have yet to find a solution to this problem other than to refinish and polish the entire slab so it all has the same polish.
Please keep in mind that that some of these problems may be the result of improper application and not necessarily the resin itself. Just like any other industry, quality control can be an issue, and sometimes a slab or two may slip by. This is why it is important to deal with reputable slab distributors and to carefully inspect each slab upon delivery.
Only time and history will tell if the resining process is good, bad or ugly. Of course, resin chemistry will most likely improve, as well as the application process. In the meantime, stone fabricators should be aware of these problems and learn to deal with them.
Fred Hueston is founder of The National Training Center for Stone and Masonry Trades, a successful marble and stone consulting and training company. He is recognized as a nationally known consultant and has written over 28 books on the subject. If you have any questions for The Technical Forum, please
e-mail Fred Hueston at fhueston@aol.com.
Friday, November 9, 2007
Thursday, November 8, 2007
Whats Under Your Carpeting
What’s Under Your Carpeting
By Frederick M. Hueston
If your building was built prior to 1980 chances are you are hiding one of the most beautiful, elegant and sustainable floor materials. That material is known as Terrazzo. Today, sustainability or what is more commonly known as Going Green is rapidly being required by many school systems, governments and private industry. Of all the materials that can be used for flooring there are only a few that qualify as sustainable and are considered safe. They are stone and terrazzo. However, even these materials can contribute to pollution and pose all kinds of health and safety risks if not properly cared for.
Why should you be concerned about your carpets and other flooring? The General accounting office of the EPA reports that one of the top five health concerns is Indoor Air Quality. In addition they report that nearly 50% of the US schools have this problem.
The following article will outline some of the hazards associated with other floor materials such as carpet and vinyl, as well as present a truly sustainable restoration and maintenance process for stone and terrazzo flooring. This information should help with your quest to improve indoor air quality in your school or building.
Carpet
Of the entire floor covering available carpet is the most popular and also the most hazardous. New and Old carpet alike emit harmful VOC’s (volatile organic Compounds) into the air. Solvents such as toluene, benzene, formaldehyde, ethyl benzene, styrene, acetone and the list goes on and on. Carpets are also a great breeding ground for dust mites, fleas and other insects as well as toxic molds and mildew. In addition carpet cleaning chemicals have been linked to diseases such as Kawasaki’s, fibromyologia and allergies.
Carpet in schools, offices and other public and private buildings are even more hazardous due to the number of people who not only walk on them but also people deposit skin cells, dust etc, not to mention food and drink that is spilled on them which provides the organic material necessary for bacteria to grow and thrive.
Of all the floor coverings carpet has the shortage service life.
Vinyl Composition Tile(VCT)
VCT is just as hazardous as carpet and possibly even more. The Adhesives used to attach VCT emit high levels of VOC’s. Since VCT is a tile moisture is often found between the tiles where toxic mold can grow.
VCT is found in almost all schools, government buildings etc. VCT is very inexpensive. VCT is made ( insert what it is made of here)
In addition to VCT composition almost all of it is maintained with harmful acrylic coatings. These coating need to be removed(stripped) and the strippers used contain hazardous chemicals as well(see article titled(Are Floor Strippers Safe). The Environmental Protection Agency(EPA) recommends that any major maintenance be performed only when the school is unoccupied for 48 hours.
Agglomerates
Agglomerated tile is composed of real stone fragments and polyester or epoxy resins. Some name brands include Fritz tile, Rover, Etc. The manufacturing process uses synthetic resins that emit high amounts of VOC’s
Agglomerates are often maintained using the same hazardous coatings and strippers used on VCT
Terrazzo and Stone
Marble, Granite, limestone, slate and terrazzo are the only true sustainable floor coverings. Stone is all natural and contains no harmful VOC’s or any other hazardous elements. They are manufactured by mother earth and there fabrication uses only water and abrasives. Terrazzo is composed of natural stone and Portland cement and is also very sustainable. In addition Natural Stone and Terrazzo flooring is long lasting. Just look at some of the buildings in Italy, France and other countries around the world. Some of these stone floors are hundreds of years old.
The dangers with stone and terrazzo floors come with the restoration and maintenance of these surfaces. Hazardous chemicals, polishes, sealers etc are often used for restoration and maintenance. These chemicals are as hazardous as the waxes and strippers used on VCT and agglomerated floor coverings.
The good news is that Stone and Terrazzo flooring can be restored and maintained with no harmful or hazardous chemicals. The restoration process uses only water and abrasives. Daily maintenance can be carried out using only Green Seal approved neutral cleaners.
If your floors are currently covered with carpet, vinyl etc.you may want to consider removing these harmful and dangerous floor coverings and restoring the terrazzo or stone that is under them.
Note: If you floors are not stone or terrazzo and are only concrete. Concrete can be polished and maintained as well.
www.ntc-stone.com www.stoneuniversity.org
By Frederick M. Hueston
If your building was built prior to 1980 chances are you are hiding one of the most beautiful, elegant and sustainable floor materials. That material is known as Terrazzo. Today, sustainability or what is more commonly known as Going Green is rapidly being required by many school systems, governments and private industry. Of all the materials that can be used for flooring there are only a few that qualify as sustainable and are considered safe. They are stone and terrazzo. However, even these materials can contribute to pollution and pose all kinds of health and safety risks if not properly cared for.
Why should you be concerned about your carpets and other flooring? The General accounting office of the EPA reports that one of the top five health concerns is Indoor Air Quality. In addition they report that nearly 50% of the US schools have this problem.
The following article will outline some of the hazards associated with other floor materials such as carpet and vinyl, as well as present a truly sustainable restoration and maintenance process for stone and terrazzo flooring. This information should help with your quest to improve indoor air quality in your school or building.
Carpet
Of the entire floor covering available carpet is the most popular and also the most hazardous. New and Old carpet alike emit harmful VOC’s (volatile organic Compounds) into the air. Solvents such as toluene, benzene, formaldehyde, ethyl benzene, styrene, acetone and the list goes on and on. Carpets are also a great breeding ground for dust mites, fleas and other insects as well as toxic molds and mildew. In addition carpet cleaning chemicals have been linked to diseases such as Kawasaki’s, fibromyologia and allergies.
Carpet in schools, offices and other public and private buildings are even more hazardous due to the number of people who not only walk on them but also people deposit skin cells, dust etc, not to mention food and drink that is spilled on them which provides the organic material necessary for bacteria to grow and thrive.
Of all the floor coverings carpet has the shortage service life.
Vinyl Composition Tile(VCT)
VCT is just as hazardous as carpet and possibly even more. The Adhesives used to attach VCT emit high levels of VOC’s. Since VCT is a tile moisture is often found between the tiles where toxic mold can grow.
VCT is found in almost all schools, government buildings etc. VCT is very inexpensive. VCT is made ( insert what it is made of here)
In addition to VCT composition almost all of it is maintained with harmful acrylic coatings. These coating need to be removed(stripped) and the strippers used contain hazardous chemicals as well(see article titled(Are Floor Strippers Safe). The Environmental Protection Agency(EPA) recommends that any major maintenance be performed only when the school is unoccupied for 48 hours.
Agglomerates
Agglomerated tile is composed of real stone fragments and polyester or epoxy resins. Some name brands include Fritz tile, Rover, Etc. The manufacturing process uses synthetic resins that emit high amounts of VOC’s
Agglomerates are often maintained using the same hazardous coatings and strippers used on VCT
Terrazzo and Stone
Marble, Granite, limestone, slate and terrazzo are the only true sustainable floor coverings. Stone is all natural and contains no harmful VOC’s or any other hazardous elements. They are manufactured by mother earth and there fabrication uses only water and abrasives. Terrazzo is composed of natural stone and Portland cement and is also very sustainable. In addition Natural Stone and Terrazzo flooring is long lasting. Just look at some of the buildings in Italy, France and other countries around the world. Some of these stone floors are hundreds of years old.
The dangers with stone and terrazzo floors come with the restoration and maintenance of these surfaces. Hazardous chemicals, polishes, sealers etc are often used for restoration and maintenance. These chemicals are as hazardous as the waxes and strippers used on VCT and agglomerated floor coverings.
The good news is that Stone and Terrazzo flooring can be restored and maintained with no harmful or hazardous chemicals. The restoration process uses only water and abrasives. Daily maintenance can be carried out using only Green Seal approved neutral cleaners.
If your floors are currently covered with carpet, vinyl etc.you may want to consider removing these harmful and dangerous floor coverings and restoring the terrazzo or stone that is under them.
Note: If you floors are not stone or terrazzo and are only concrete. Concrete can be polished and maintained as well.
www.ntc-stone.com www.stoneuniversity.org
Going Green Means More Green $$$ in your pocket
Going Green Means More Green $$$ in your pocket
By Frederick M. Hueston
Unless you have been living under a rock the last ten years(no pun intended),going green is something you have at least heard of. Now , most of us that run a stone fabrication shop rarely think of going green and protecting the environment. However, this is something that will change in the years to come and its something that every stone shop should be thinking about. Before I discuss how to go green and how it can benefit your shop lets first define what going green means. According to the US Green Building Council green is "Principles that minimize the use of nonrenewable resources and seek to prevent air, water and ground contamination and other activities that degrade the environment." Lets look at this a little closer and how it can not only help planet earth, but how it can put more "green" in your pocket. First, going green is not a requirement or a law at this time. It is strictly voluntary. The following statement is from http://www.usgbc.org, which is the website to go to for all the information you will need on green. LEED(Leadership in Energy and Environmental Design) Green Building Rating System is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. So, if this is not a requirement why should I care you might ask? The following are several reasons:
Stone is Green. Just think about this for a moment. We are selling mother earth herself. Let us not forget that we are dealing with a natural resource. What better selling point then to advertise and market the fact that you are using a green product. Not only homeowners, but architects and designers both are keen to use green products. One of the latest trends in building design is to use recyclable building materials. Why recycle when you can use a natural green product such as stone.
Competitive Edge- Going green will give you one up on your competitors. What better way to gain the competitive edge then to let your potent ional customers know that you are not only working with a green product but your business is concerned with mother earth.
Save the Planet- What can be more satisfying in knowing that you are helping save the plant.
What can you do to go green in your shop.
Recycle and filter your water- Water recycling and filtering in many towns is now a requirement and will soon be a requirement all over the US. This is especially true in areas where water is scarce. There are several companies that now make recycling and filtration equipment. For a list of companies
Go Wet- It surprises me how many shops today are still cutting, grinding and polishing stone dry. In my book this is a no-no. Dry cutting and grinding releases silica dust in the air which can cause siliceous, a very serious lung disease.
Recycle your stone- See the next section below on what to do with your stone waste.
Build with Green Materials- There are many new material for building that are made from recycled materials such as tires, plastic milk jugs and other materials that are normally just thrown away.
Use Natural Floor Materials- get rid of the carpets and install stone flooring in your showroom and office. This will also help you sell more stone.
Use non toxic chemicals- use water based sealers and cleaners. Try to stay clear of solvent based materials.
What to do with your stone waste
Many fabricators have a big issue with there stone waste. I talked with a fabricator recently that was spending over $2000 per month on disposal of their stone waste. There are several ways to dispose of your waste and even a few where you can generate more green$$$$
Here are a few suggestions:
Have a weekend sale. I know several fabricators who open up there stone yard to the general public and sell there waste for next to nothing. Some even give it away. Take a small ad in the newspaper and advertise it. You can make some extra money by charging the customer to cut the piece or even profile and polish it. I know one fabricator who made over $35000.00 on one weekend with this method.
Tumble it- Tumble stone is big and customers love it. Why not take you waste, cut it into small tiles and tumble it. These tiles can be sold for as much as $20 each.
Give it away to artist and craftspeople- if you are in an area that has a large arts and crafts community, why not give it away. You wont be making any money on it but on the other hand you wont be spending it to get rid of it.
Sidewalks and patios- what about using it in sidewalks and patios. Masons get some big dollars for this type of work and it looks great. Terrazzo companies may also be interested in it for what is knows as palandiana terrazzo.
Chicken Grit- Buy and rock crusher and grind the stone into fine grit and sell it to chicken farmers as chicken grit.
www.ntc-stone.com and www.stoneuniversity.org
By Frederick M. Hueston
Unless you have been living under a rock the last ten years(no pun intended),going green is something you have at least heard of. Now , most of us that run a stone fabrication shop rarely think of going green and protecting the environment. However, this is something that will change in the years to come and its something that every stone shop should be thinking about. Before I discuss how to go green and how it can benefit your shop lets first define what going green means. According to the US Green Building Council green is "Principles that minimize the use of nonrenewable resources and seek to prevent air, water and ground contamination and other activities that degrade the environment." Lets look at this a little closer and how it can not only help planet earth, but how it can put more "green" in your pocket. First, going green is not a requirement or a law at this time. It is strictly voluntary. The following statement is from http://www.usgbc.org, which is the website to go to for all the information you will need on green. LEED(Leadership in Energy and Environmental Design) Green Building Rating System is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. So, if this is not a requirement why should I care you might ask? The following are several reasons:
Stone is Green. Just think about this for a moment. We are selling mother earth herself. Let us not forget that we are dealing with a natural resource. What better selling point then to advertise and market the fact that you are using a green product. Not only homeowners, but architects and designers both are keen to use green products. One of the latest trends in building design is to use recyclable building materials. Why recycle when you can use a natural green product such as stone.
Competitive Edge- Going green will give you one up on your competitors. What better way to gain the competitive edge then to let your potent ional customers know that you are not only working with a green product but your business is concerned with mother earth.
Save the Planet- What can be more satisfying in knowing that you are helping save the plant.
What can you do to go green in your shop.
Recycle and filter your water- Water recycling and filtering in many towns is now a requirement and will soon be a requirement all over the US. This is especially true in areas where water is scarce. There are several companies that now make recycling and filtration equipment. For a list of companies
Go Wet- It surprises me how many shops today are still cutting, grinding and polishing stone dry. In my book this is a no-no. Dry cutting and grinding releases silica dust in the air which can cause siliceous, a very serious lung disease.
Recycle your stone- See the next section below on what to do with your stone waste.
Build with Green Materials- There are many new material for building that are made from recycled materials such as tires, plastic milk jugs and other materials that are normally just thrown away.
Use Natural Floor Materials- get rid of the carpets and install stone flooring in your showroom and office. This will also help you sell more stone.
Use non toxic chemicals- use water based sealers and cleaners. Try to stay clear of solvent based materials.
What to do with your stone waste
Many fabricators have a big issue with there stone waste. I talked with a fabricator recently that was spending over $2000 per month on disposal of their stone waste. There are several ways to dispose of your waste and even a few where you can generate more green$$$$
Here are a few suggestions:
Have a weekend sale. I know several fabricators who open up there stone yard to the general public and sell there waste for next to nothing. Some even give it away. Take a small ad in the newspaper and advertise it. You can make some extra money by charging the customer to cut the piece or even profile and polish it. I know one fabricator who made over $35000.00 on one weekend with this method.
Tumble it- Tumble stone is big and customers love it. Why not take you waste, cut it into small tiles and tumble it. These tiles can be sold for as much as $20 each.
Give it away to artist and craftspeople- if you are in an area that has a large arts and crafts community, why not give it away. You wont be making any money on it but on the other hand you wont be spending it to get rid of it.
Sidewalks and patios- what about using it in sidewalks and patios. Masons get some big dollars for this type of work and it looks great. Terrazzo companies may also be interested in it for what is knows as palandiana terrazzo.
Chicken Grit- Buy and rock crusher and grind the stone into fine grit and sell it to chicken farmers as chicken grit.
www.ntc-stone.com and www.stoneuniversity.org
Training and Edcation for the Stone Industry
Training and Education for the Stone Industry
by Frederick M. Hueston
Many industries have formal training programs where you can learn the trade. There are programs for general contractors, electricians, plumbers, carpenters etc. Many of these classes are offered by community and technical colleges. What about the stone Industry? Where does one go to learn how to install, fabricate or restore stone?
A little History
The stone industry has really never had any formal training programs in the past. All the training was done on the job. There were lecture based short seminars that were offered at trade shows and expos but these were very generic and did not provide hands on training.
In 1991 the first formal training program was developed by Fred Hueston, who founded The National Training Center for Stone & Masonry Trades(NTC). This first class incorporated lecture as well as actual hands on training. The course was outlined and developed as if it were developed for a trade school or college.
Today, many others offer training programs, however these programs are sponsored and presented by distributors and suppliers who have an interest in selling their products. There is still useful information to learn from these courses but one must be careful and beware of a sales pitch.
When choosing a training course you want to make sure that the instructors are experienced in their respected craft. While experience is critical the instructor must also have the ability to teach. I have seen many instructors and presenters in this industry that like to hear themselves talk and have little or no concern as to weather you are learning the material.
All too often instructors do not have their facts straight and will make up facts. I have seen this many times. A good instructor will make sure to point out facts, back them up with proof. If an opinion is offered it will be clear that it is an opinion.
Types of Training
There are several ways to receive training and many methods. The following will explore these methods.
Lecture
Lecture is the most popular training. This is where the instructors gets up in front of a group and presents. He/she may use power point, slides, flip charts,video, etc to emphasis points. This is the method of presentation that you will see at trade shows and expos.
The advantage of lecture methods is that a lot of information can be presented. The disadvantage is that the student will rarely absorb all this information. This is why it is important to have all the information presented in hand outs etc. Another disadvantage is that adults can bored easily.
Hands On
Hands on training is perhaps the best way to learn any of the stone trades. This is where the student actually gets to work with the tools etc. One must be careful when looking at training programs that advertise Hands On. If the instructor is doing all the work and only demonstrating the techniques and not allowing the students to perform the tasks, this is not hands on. A true hands on class will allow you to not only work with the tools but to have time to practice the techniques etc.
Online
With the advent of the Internet, there is now training that can be taken online. This type of training was first offered by Fred Hueston of Stone University. The training is similar to the lecture method. The advantage is that all the lessons can be recorded and viewed again and again. The disadvantage is that it does not offer hands on.
Training is a continual process. The best business owners and craftsman know that they have to continue to be updated with new techniques and methods.
For further information on training visit stoneuniversity.org or ntc-stone.com
Here are some other great training resources where there is no product sales:
Natural Stone Restoration Alliance www.nsraweb.com
Stone Fabricators Alliance www.stoneadvise.com
by Frederick M. Hueston
Many industries have formal training programs where you can learn the trade. There are programs for general contractors, electricians, plumbers, carpenters etc. Many of these classes are offered by community and technical colleges. What about the stone Industry? Where does one go to learn how to install, fabricate or restore stone?
A little History
The stone industry has really never had any formal training programs in the past. All the training was done on the job. There were lecture based short seminars that were offered at trade shows and expos but these were very generic and did not provide hands on training.
In 1991 the first formal training program was developed by Fred Hueston, who founded The National Training Center for Stone & Masonry Trades(NTC). This first class incorporated lecture as well as actual hands on training. The course was outlined and developed as if it were developed for a trade school or college.
Today, many others offer training programs, however these programs are sponsored and presented by distributors and suppliers who have an interest in selling their products. There is still useful information to learn from these courses but one must be careful and beware of a sales pitch.
When choosing a training course you want to make sure that the instructors are experienced in their respected craft. While experience is critical the instructor must also have the ability to teach. I have seen many instructors and presenters in this industry that like to hear themselves talk and have little or no concern as to weather you are learning the material.
All too often instructors do not have their facts straight and will make up facts. I have seen this many times. A good instructor will make sure to point out facts, back them up with proof. If an opinion is offered it will be clear that it is an opinion.
Types of Training
There are several ways to receive training and many methods. The following will explore these methods.
Lecture
Lecture is the most popular training. This is where the instructors gets up in front of a group and presents. He/she may use power point, slides, flip charts,video, etc to emphasis points. This is the method of presentation that you will see at trade shows and expos.
The advantage of lecture methods is that a lot of information can be presented. The disadvantage is that the student will rarely absorb all this information. This is why it is important to have all the information presented in hand outs etc. Another disadvantage is that adults can bored easily.
Hands On
Hands on training is perhaps the best way to learn any of the stone trades. This is where the student actually gets to work with the tools etc. One must be careful when looking at training programs that advertise Hands On. If the instructor is doing all the work and only demonstrating the techniques and not allowing the students to perform the tasks, this is not hands on. A true hands on class will allow you to not only work with the tools but to have time to practice the techniques etc.
Online
With the advent of the Internet, there is now training that can be taken online. This type of training was first offered by Fred Hueston of Stone University. The training is similar to the lecture method. The advantage is that all the lessons can be recorded and viewed again and again. The disadvantage is that it does not offer hands on.
Training is a continual process. The best business owners and craftsman know that they have to continue to be updated with new techniques and methods.
For further information on training visit stoneuniversity.org or ntc-stone.com
Here are some other great training resources where there is no product sales:
Natural Stone Restoration Alliance www.nsraweb.com
Stone Fabricators Alliance www.stoneadvise.com
Black Granite Fading
By Frederick M. Hueston
I have received numerous calls lately concerning the fading of black granite counter tops.
The most common complaints seem to be on Absolute Black, Black Galaxy, Zimbabwe Black and a few others. I have heard many fabricators try to blame the fading on the mis use of cleaning chemicals, acids etc. While one should not use inapropriate chemicals on granite surfaces, this is not the reason for the increase in black granite fading.
Why does black granite fade?
The answer is, black granite should not fade. Black granite imported from Asia and India is sometimes doctored with dyes and oils to darken the surface. Dyes can include home made blends such as charcoal and linseed oil. Pre packaged color enhancers are also used to darken granite. The fading is nothing more than the dyes and oils being removed. Of course the wrong chemical will take the dye out faster but I have seen many of these dyes removed using simply water and a mild cleaner.
Here we see fading of a dyed Black Absolute Slab
This picture was taken in India showing a worker applying dye to the granite.
Dye dripping down the sides of black granite
Testing for Dyed Granite
Before purchasing a granite slab perform the following test to find out if it has been doctored.
Take a clean white rag and apply some acetone to the surface of the granite. If any residue or black color is observed on the top, do not accept it, it has been dyed. If you get no dye from the acetone then take some MEK(Methyl Ethyl Ketone) and apply to a different part of the slab. If you get any color transfer the stone is dyed. These chemicals can be purchased at most home improvement or paint supply stores.
Can Dyed Granite Be Repaired?
The reason granite is dyed is that its natural color is gray and it doesn’t have that deep black color that some black granites have. For this reason many factors use deceptive methods to doctor these slabs pawning them off as deep black granites.
Unfortunately, there is no fix. Other than to dye the granite again.
In addition to dying many types of granite are also injected with resins, which can also darken granite. For further information on the resining process see my article titled Resin Slabs, The Good, The Bad and The Ugly at www.stoneworld.com.
Fred HuestonFred Hueston and AssociatesStone University(stoneuniversity.org)The National Training Center for Stone and Masonry Trades(ntc-stone.com)828-301-9796321-441-3784http://www.ntc-stone.com/http://www.stoneuniversity.org/
Comparison of Two Maintenance Systems for stone
Purpose of Study: To compare and evaluate the advantages,disadvantages,required labor of two popular stone maintenance programs.
Introduction: The maintenance of stone flooring in the United States today is a million dollar a year business and continues to grow. This increased growth results from the desire to maintain a highly polished mirror finish. As of this date there are basically two methods to keep stone in this condition. One method is to place some type of a coating on the surface of the stone. These coatings can be natural or synthetic waxes, acrylics, urethanes and epoxies. The majority used today on marble are composed of acrylics. The second method used to maintain stone is to polish the stone with the use of abrasive diamonds and polishing powders. This method uses no coatings. It simply smooths the stone to produce a high shine. The purpose of this study is to compare the advantages and disadvantages of these two methods as well as their labor and material requirements. A third method becoming popular is the use of flurosilicate compounds applied to the stone. This method is commonly called Recrystallazation or Vitrification and is applied as a final finish in place of powder polishing or it is applied on top of the polished finish for added shine. This study will not address this process.
Maintenance of coatings:
Once a stone floor is coated the following is the standard procedure for maintenance:
1. The entire floor is dust mopped(daily) .
2. The floor is then damp mopped or machine scrubbed with a neutral cleaner(daily).
3. Worn areas are spray buffed using a standard floor machine and a red pad. If a high speed finish is used the floor is burnished using a high speed buffer(daily).
4. Areas that do not shine after buffing or spray buffing are re-coated(daily as needed).
5. Periodically the floor is stripped and re-coated(every six
months or more often).
Maintenance using honing and polishing.
Once the stone floor is honed and polished the following is the standard procedure for maintenance:
1. The entire floor is dust mopped(daily).
2. The floor is damp mopped or machine scrubbed with a neutral cleaner or stone soap(two-three times per week).
3. Traffic areas are polished with polishing powder(once per week in high traffic, less often in lower traffic).
4. Severely worn areas are lightly honed and re-polished(once every six months)
Both maintenance procedures described above are typical. Frequencies will vary depending on traffic, type of stone and desired finish. Both procedures assume that floor is in maintainable condition at start of maintenance program.
Method of study
In order to evaluate both of the above methods three commercial lobby floors were studied. All three floors have used both methods for a period of one year or more. Maintenance personnel and executive housekeepers were interviewed to obtain costs, advantages and disadvantages of both methods. Since hourly labor rates vary from state to state, this study will provide labor hours only.
Case Study #1
Property
Busy Hotel lobby located near a major theme park.
Floor Description
12,000 square feet of rosa perlino marble in a palandiana terrazzo pattern.
Very busy lobby. Traffic areas include large reception check in and four elevator banks. Floor is adjacent to a swimming pool area.
Maintenance procedure(coating) from date of installation to 1992.
When floor was complete several coats of a carnauba based sealer was applied.
1. Floor was dust mopped daily in the evenings during third shift.
2. Floor was wet mopped daily using a commercial, neutral floor cleaner.
3. Floor was spray buffed every night to remove scuffing, black heel marks and wear.
4. Floor was recoated daily in heavy traffic areas with a light coat of the carnauba based sealer.
Total daily man hours required 16 hours
Comments on maintenance program(coating) from staff and executive housekeeper:
Floor very difficult to maintain. It appears to mar, scuff very easily.
Once floor is spray buffed it looks great but once traffic starts the finish rapidly deteriorates.
The finish on the floor is turning yellow and becoming very dark and dirty looking.
The wax is accumulating in holes in the marble and turning black.
Maintenance procedure(polishing)from 1992 to present.
In 1992 the entire floor was stripped, the holes filled and then honed and polished using standard marble polishing powders.
1. Floor is dust mopped every evening.
2. Floor is damp mopped three times per week using a stone soap.
3. Traffic areas are re-polished once every two weeks using standard marble polishing powders.
4. As of this date no re-honing has been performed. Inspection of the floor and wearability indicates that honing of traffic areas will need to be about once per year.
Total daily man hours required 6 hours
Comments on maintenance program(polishing) from staff and executive housekeeper.
Our labor costs have been cut dramatically and the floor looks and stays clean longer.
Dirt doesn't seem to stick to the floor like it did before.
Case Study #2
Property
Busy hotel lobby, located next to major interstate exchange.
Floor description
3500 Square feet of rosa alicante marble, 12x12 inch tiles.
Busy hotel lobby floor. Constant traffic due to adjacent meeting rooms.
Maintenance procedure(coating) prior to 1992
Floor was initially stripped and several coats of an acrylic floor finish were applied.
1. Floor was dust mopped daily.
2. Floor was wet mopped daily with a neutral cleaner.
3. Once per month the entire floor was re-coated with acrylic floor finish. No spray buffing was performed between re-coatings.
4. Once every three months the entire floor was stripped and re-coated.
Total daily hours required- 4 hours
Comments on maintenance program(coating)from staff and executive housekeeper.
Floor looks great for one day a month, immediately after it is re-waxed. During the remaining time it looks just terrible.
Floor has a real plastic look, it doesn't even look like marble anymore.
The bellman carts are leaving marks on the floor all over and the area in front of the reception desk is very dull.
Maintenance procedure(polishing)from 1992 to present.
The entire floor was stripped to remove all the old wax, re-honed and then powder polished using standard marble polishing powders.
1. Floor is dust mopped daily.
2. Floor is wet mopped daily.
3. Traffic areas are re-polished once per week using polishing powder.
4. As of this date re-honing is required about once per year of approx. 800 square feet.
Total daily man hours required 1 3/4 hours.
Comments on maintenance program(polishing)from staff and executive housekeeper.
Our floor looks like marble again and the carts are no longer marking the floor.
Dust mopping and wet mopping are now a snap. The mop seems to glide very easily over the floor and we are not picking up as much dirt as before.
Case Study #3
Property
High rise apartment building lobby located in Canada
Floor description
1000 square feet of a negro marquina and white carrara in a checker board pattern.
Very busy residential condo with approx 80 condo units.
Maintenance procedure(coating)from date of installation to 1992.
This floor has been waxed for the past several years with the following maintenance program.
1. Floor was dust mopped several times per week.
2. Floor was damp mopped several times per week, daily during the winter months.
3. Floor was spray buffed once per week.
4. Floor was stripped and re-coated with an acrylic floor finish once every three months.
Total daily man hours required 1 hour
Comments on maintenance program(coating)from staff and property manager.
Floor always looks dull and scratched.
I can never seem to keep up with the floor, it is always scuffing (Janitor)
Maintenance procedure(polishing)from 1992 to present.
Floor was stripped, ground flat, rehoned and polished using standard marble polishing powders.
1. Floor is dust mopped daily every morning.
2. Floor is damp mop once per week, daily in winter.
3. Traffic areas are repolished once per month.
Total daily man hours 25 minutes
Comments on maintenance program(polishing)from staff and property manager.
Our floor is shiny again, it looks great.
I can't believe how easy the floor is to maintain, no more stripping and waxing.
Maintenance Methods Summary
Daily labor hours required
Project Strip & Wax Hone & Polish
_________________________________________________________________
Case Study #1 16 hours 6 hours
Case Study #2 4 hours 1 3/4 hours
Case Study #3 1 hour 25 minutes
_________________________________________________________________
Material Costs:
Cost for materials and consumption was difficult to obtain from housekeeping staff. Based on guess estimates, material cost were insignificant compared to labor cost. The costs of polishing powders and diamond abrasive were slightly lower than the use of strippers and coatings.
Conclusions & Discussion
Based on the above case studies it is apparent that the honing and polishing method is more economical than the use of coatings on stone flooring. Labor costs are reduced by one-half or more.
This reduction in labor costs is a significant savings per year.
Case Study #1 is saving 3650 hours per year, at an average labor cost of $12.00 per hour this is a savings of $43,800.00 per year.
Case #2 labor savings is equal to 821 hours per year or $9852.00 per year saved based on average labor cost of $12.00 per hour.
Case #3 saves 212 hours or $2544.00 per year.
Although costs are a major consideration when comparing the above two maintenance programs, it is also apparent that their are distinct advantages to the honing and polishing program as well as some disadvantages to the coating program. Coatings will mar, scuff and wear very easily. It is a well known fact that there are no coatings currently available for stone that are harder than the stone itself. For this reason coatings will scuff and mar much more than the stone itself. It is often argued that these coatings place a sacrificial layer on the stone protecting it from dirt and staining. Although this would make sense the opposite is true. These coatings are soft and will attract dirt faster than a natural polish. This is easy to prove if one takes a section of stone floor and applies a coating and on another section performs a hone and polish. After one or two days it will be discovered that more dust and debris is attracted to the coated surface than the honed and polished surface. It will also be discovered that removing the dust and debris from the coated surface is much more difficult. Coatings also will build on the surface producing a plastic like appearance. Some coatings will also turn dark and yellow rapidity. This is especially true if the stone is exposed to ultraviolet light. The removal of coatings by the use of harsh strippers can also damage the stone. Many strippers contain Sodium Hydroxide , which can form what is known as an alkaline salt. These salts can penetrate into the stone and cause premature spalling. Some coatings may also block the breathing of the stone causing it to suffocate and rot.
How does one protect the stone from staining if coatings are not used? Stone can be protected with products known as penetrating sealers or impregnators. These materials are designed to penetrate below the surface of the stone and keeping water and debris on the surface. Since they are not a coatings they will not require repair. They do not however add gloss to the stone surface.
The following table outlines the advantages and disadvantages of the two maintenance programs studied. Although only three case studies were used, many contractors and maintenance companies were interviewed to obtain these conclusions. Those who use the hone and polishing programs are very pleased and will not return to the old strip and coat method. Those companies interviewed who use the strip and coat method were not aware that another program existed.
Although this study shows that the polishing method is more economical, caution is advised. Each case must be studied carefully. Labor skill, budget requirements and existing condition of the stone must be evaluated before choosing the proper maintenance system. Those using marble polishing powders and diamond abrasives must be trained in there proper application. There are many quality coatings available that may be a good alternative to the above system if these special skills are not available. It is advisable to contact a reputable stone maintenance professional for advise.
Advantages & Disadvantages Summary
Coatings- Advantages
* Can be repaired by buffing
* Easy to apply
* Provides a sacrificial Coating(?)
Coatings- Disadvantages
* Will mar and scuff
* Can Yellow
* Stripping is required
* Can appear plastic-like
* Can block breathing of stone causing spalling
* Will attract dirt like a magnet.
* Labor intensive
Hone and polish-Advantages
* Will not scuff and mar
* Provides a natural shine
* Longer lasting than coatings
* Allows stone to breathe
* Reduced labor costs
Hone and polish- Disadvantages
* Increased skill level- Training required
* Does not provide stain protection
Fred Hueston is the founder of The National Training Center for Stone and Masonry Trades(www.ntc-stone.com) and Stone University(www.Stoneuniversity.org)
Tuesday, November 6, 2007
Deicers are killing your stone and terrazzo Flooring
Are your Ice and Snow Melters Destroying your Stone and Terrazzo Floors
The Deterioration of Stone & Masonry through the Crystallization of Deicing Salts
Frederick M. Hueston
The crystallization of deicing salts found in many snow and ice melter can cause severe deterioration of stone, terrazzo and masonry surfaces. This crystallization is called subflorescence. Snow and Ice Melters containing Calcium Chloride, etc are the cause for this damage. .Problems associated with subflorescence can be diagnosed and identified by visual clues, such as spalling and pitting. Accurate diagnosis of subflorescence can be confirmed with laboratory testing. Preventative applications might include application of chemical injection and coating the masonry with a sealer or impregnator as well as switching to a snow and ice melter that contain non-crystalline salts. The following article will explore the problems caused by these deicers and what can be done to prevent damage to your stone, terrazzo or masonry floors.
How do Deicer Cause Damage
The deposit of salts in the pores of stone and masonry is the major cause for deterioration of these surfaces. These salts are contained in many popular snow and ice melters. Boyer(1986) contributes deicing salts
When snow and ice melts the salts used in deicers become soluble. The water wicks into the pores of the stone and masonry carrying the salts with it. When the water evaporates the salts recrystallize. The pressure created in the pores of the stone and masonry cause the surface to flake off or spall. This process is known as subflorescence.
4
Diagnosing and Identifying Subflorescence
An experience stone consultant can recognize the signs and symptoms of damage caused by deicing salts. The stone and masonry will appear pitted(spalled). This damage is observed in the walking path at the entrances of the building. The damage tends to lessen the further away from the entrance. Certain stones such as some limestone’s and slates will flake off in sheets. Terrazzo and marble will become pitted.
Core samples can also be taken and sent to a lab for testing and verification if necessary.
Snow and Ice Melters
There are many brands of snow melters on the market. Many of these melters contain salts that will crystallize and cause damage to stone and masonry. The following are the salts you should avoid.
Rock Salt- Rock salt will go by the name of Halite but chemically it is simply Sodium Chloride(NaCl). This is the most common salt sold for deicing and it is also the least expensive and hence is the most widely used. It is also the salt that causes the most damage to stone, terrazzo and masonry flooring.
Calcium and Magnesium Chloride(CaCl2 –MgCl2)- these are salts that come from natural salt deposits in the Great Salt Lake in Utah. They are also destructive to stone, terrazzo and masonry. They also can deposit a film on the surface of the floor causing it to be slippery.
Potassium Chloride(KCL)- This salt is not a very good deicer by itself and is often found mixed with other ingredients. It is often sold as a safer salt for plants. But not for stone, terrazzo or masonry.
Ammonium Sulphate(NH4]2SO4 Stay far away from this salt. It is very damaging to stone, terrazzo and masonry. It’s not used that much in deicers but if you see it listed on the ingredients, don’t buy it.
Urea- Urea is commonly found in fertilizers. In its pure form it is less damaging the most other salts. Most deicers containing Urea are not pure and can be damaging to stone, terrazzo and masonry.
The above salts are in a sold crystalline form. There are liquid deicers available containing Ethylene Glycol and Potassium acetate but liquids are usually impractical to apply in schools and other public buildings.
Safe Deicers
Which salts are safe for stone, terrazzo and masonry flooring? Thanks to our many icy roads a salt known as Calcium Magnesium acetate was developed. Not only is this type of deicer more environmentally friendly it is also biodegradable, non corrosive and less damaging to stone, terrazzo and masonry surfaces. The down side you might guess is the expense. But what will that new floor cost?
Safe for Concrete Deicers
The biggest concern with deicers is the corrosion of rebar in concrete. For this reason many deicers are claiming to be safe for concrete. This is true as far as less corrosion. Your concern is not necessarily corrosion but salt crystallization. Make sure to check the ingredient of these so called safer deicers by requesting a Material Safety Data Sheet (MSDS) or consult with a stone expert.
As I travel in areas where deicer are used I see thousands of schools, government buildings as well as public building with damage to stone, terrazzo and masonry flooring. If the damage is caught in time a restoration company may be able to repair the damage. If these harmful salts continue to be used you’ll be replacing the flooring in a very short time.
The Deterioration of Stone & Masonry through the Crystallization of Deicing Salts
Frederick M. Hueston
The crystallization of deicing salts found in many snow and ice melter can cause severe deterioration of stone, terrazzo and masonry surfaces. This crystallization is called subflorescence. Snow and Ice Melters containing Calcium Chloride, etc are the cause for this damage. .Problems associated with subflorescence can be diagnosed and identified by visual clues, such as spalling and pitting. Accurate diagnosis of subflorescence can be confirmed with laboratory testing. Preventative applications might include application of chemical injection and coating the masonry with a sealer or impregnator as well as switching to a snow and ice melter that contain non-crystalline salts. The following article will explore the problems caused by these deicers and what can be done to prevent damage to your stone, terrazzo or masonry floors.
How do Deicer Cause Damage
The deposit of salts in the pores of stone and masonry is the major cause for deterioration of these surfaces. These salts are contained in many popular snow and ice melters. Boyer(1986) contributes deicing salts
When snow and ice melts the salts used in deicers become soluble. The water wicks into the pores of the stone and masonry carrying the salts with it. When the water evaporates the salts recrystallize. The pressure created in the pores of the stone and masonry cause the surface to flake off or spall. This process is known as subflorescence.
4
Diagnosing and Identifying Subflorescence
An experience stone consultant can recognize the signs and symptoms of damage caused by deicing salts. The stone and masonry will appear pitted(spalled). This damage is observed in the walking path at the entrances of the building. The damage tends to lessen the further away from the entrance. Certain stones such as some limestone’s and slates will flake off in sheets. Terrazzo and marble will become pitted.
Core samples can also be taken and sent to a lab for testing and verification if necessary.
Snow and Ice Melters
There are many brands of snow melters on the market. Many of these melters contain salts that will crystallize and cause damage to stone and masonry. The following are the salts you should avoid.
Rock Salt- Rock salt will go by the name of Halite but chemically it is simply Sodium Chloride(NaCl). This is the most common salt sold for deicing and it is also the least expensive and hence is the most widely used. It is also the salt that causes the most damage to stone, terrazzo and masonry flooring.
Calcium and Magnesium Chloride(CaCl2 –MgCl2)- these are salts that come from natural salt deposits in the Great Salt Lake in Utah. They are also destructive to stone, terrazzo and masonry. They also can deposit a film on the surface of the floor causing it to be slippery.
Potassium Chloride(KCL)- This salt is not a very good deicer by itself and is often found mixed with other ingredients. It is often sold as a safer salt for plants. But not for stone, terrazzo or masonry.
Ammonium Sulphate(NH4]2SO4 Stay far away from this salt. It is very damaging to stone, terrazzo and masonry. It’s not used that much in deicers but if you see it listed on the ingredients, don’t buy it.
Urea- Urea is commonly found in fertilizers. In its pure form it is less damaging the most other salts. Most deicers containing Urea are not pure and can be damaging to stone, terrazzo and masonry.
The above salts are in a sold crystalline form. There are liquid deicers available containing Ethylene Glycol and Potassium acetate but liquids are usually impractical to apply in schools and other public buildings.
Safe Deicers
Which salts are safe for stone, terrazzo and masonry flooring? Thanks to our many icy roads a salt known as Calcium Magnesium acetate was developed. Not only is this type of deicer more environmentally friendly it is also biodegradable, non corrosive and less damaging to stone, terrazzo and masonry surfaces. The down side you might guess is the expense. But what will that new floor cost?
Safe for Concrete Deicers
The biggest concern with deicers is the corrosion of rebar in concrete. For this reason many deicers are claiming to be safe for concrete. This is true as far as less corrosion. Your concern is not necessarily corrosion but salt crystallization. Make sure to check the ingredient of these so called safer deicers by requesting a Material Safety Data Sheet (MSDS) or consult with a stone expert.
As I travel in areas where deicer are used I see thousands of schools, government buildings as well as public building with damage to stone, terrazzo and masonry flooring. If the damage is caught in time a restoration company may be able to repair the damage. If these harmful salts continue to be used you’ll be replacing the flooring in a very short time.
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