Sealers

[John Bridge]

Copied by JB from Thread No. 5904 (Professionals' Hangout)


kemguru
Restoration Specialist

Registered: Nov 2002
Location: Denver, Colorado
Posts: 264
I started a response to this last night, and well, just as I hit my 7th page use Word I decided I would not bore most folks with this subject.

Bottom line is most impregnators on the market clog pores, just as Maurizio states. They do allow for SOME vapor transmission, but usually not enough, especially in a shower environment were there may be moisture seeping in from any of multiple locations.

Silicones, which include silanes and siloxanes (same animal), silicates, epoxy and vinyl resins can and will clog pores.

Solvent-based impregnators tend to have a lower surface tension. Most are formulated with N-Heptane, a solvent with a very low surface tension (19 dynes/cm3). Surface tension is what everything is based on when it comes to “sealing”. The lower the better. This is why solvent-based technology is usually best (among a few other reasons). A low-tension product can penetrate deeper into the surface and provide a sub-surface barrier with a low-tension rating. But truth be told, the technology does exist to formulate a water-based product with 1/3 the tension of any solvent-based product on the market, but you good folks would not want to pay the $1000 or so a gallon it would cost.

Again, everything is based on surface tension. When cleaning a surface, you need a product that is low enough in tension to get between the bond of the contaminant and the surface and break that bond. Water based contaminants tend to have a tension of around 35 (give or take here) and oil based contaminants are around 25 (again, give or take a bit). This same rule applies to impregnators and seals. If the protectants surface tension is lower than 35 but higher than 25, this protectant becomes water repellant and not a stain repellant. But if a protectant falls below 25 it becomes both water and stain repellent.

Dense surfaces need a product very low in surface tension to allow for adequate penetration (he he he…. yes I said adequate penetration). THIS HAS NOTHING TO DO WITH MOLECULAR SIZE EVERYBODY!!!! Jeeez people, a molecule is anything composed of at least two different atoms. ATOMS!!! Molecular size and blah, blah, blah sound great as a sales pitch, but this is B.S.!!

I have done extensive research on this subject, sort of a life’s work if you will. Years ago, 3M (the makers of Scotch Guard) had a raw material called FC-759. This was the king of the hill for fluoro technology. Well, the EPA stepped in, and 3M being the good company they are, stopped manufacturing it. Everybody’s research, as well as products based on this technology, went down the tubes. Back to the drawing board folks. Now this technology is back, stronger and better than ever before.

We are now crossing over into reactive impregnators. Products that physically change the make-up of the surface, not clogging pores. Clogging pores is easy, just pour some oil on the surface, like a lot of old timers used to do, and, well, what do ya know…its sealed. Duh.

I have worked with the likes of Dupont, 3M, Dow and many other smaller guys. We flat stole the technology from carpet folks (yup all you tile guys…. carpet guys) and adapted it for our own use. This required a lot of research, but years ago, when I sealed a piece of SILK with FC-759 and it held brake fluid for 24 hours, yet I could still breath (blow air) through the SILK, I was sold.

So, please keep an open mind everybody. I will share notes with anybody that is in a position to do so. I have pages of information to add here, and I will happily, just ask away.

Bottom line? Newer products, or old ones being re-formulated, based on fluoro chemicals (be it fluoropolymers or fluorosurfactants) are hitting the market everyday. THESE PRODUCTS WILL NOT CLOG PORES…PERIOD.





04-14-2003 03:53 PM

[John Bridge]

kemguru
Restoration Specialist

Registered: Nov 2002
Location: Denver, Colorado
Posts: 264
Water-based technology has absolutely taken off in the past few years. Current solvent-based technology has been in use for many years now, excluding solvent-based fluoropolymers. We can thank the EPA and the Democrats (another subject) for forcing us into “accelerating” the development of lower VOC products. I am not saying solvent-based is better…it WAS better. Yes, in the past, solvent-based products would penetrate denser stones with ease compared to water-based technologies. This is partially due to their make-up from the get go. Every resin, except silicates, dissolves in a solvent. These same resins can be mixed with water, but they then become an emulsion. Another words, just small particles of the resin floating around in water. Polymer size does matter here, but again, not molecular size.

Fast forward a few years.

We now have fluorochemicals. Still the same basics here. The majority of the fluorinated materials being used are acrylic. Acrylics dissolve in a solvent, but can become an emulsion in water when washed with a surfactant to “soften” it up. Now, for acrylic coatings, this washing weakens the polymer. Think about the difference in strength between a solvent-based acrylic coating and a water-based acrylic coating. Water-based acrylic COATINGS are weaker. This does not matter when it come to impregnators. Impregnators are sub-surface protectants, we don’t care about their scratch and scuff resistance. So water-based technologies work fine here. But we still had a problem. The fluoropolymers were performing, but not as well as they do in the textile industry. Remember, we are hard surface folks here, not no stinkin carpet dudesJ Kidding JC!!! We need heat!! Textiles are submerged into a fluoropolymer bath, then heated to activate the polymer “tails”. Think sperm here folks, looks about the same. They plant their little heads into a surface and its their tails that are providing the protection. No shit! So once again, solvent-based wins. Solvents provided the flash cure we needed to activate those tails. As good as the heat treatment used at carpet and textile plants? Nope, and we are yet to be there even today, but good enough.

Fast forward another year or two.

We are really onto something here! We have the solvent-based technology kicking conventional impregnator ass now. But that damn VOC regulation everybody has to meet, and its only going to get worse. Water-based is where its at. So we start barking up the ketones tree. MEK and Acetone. Worked a bit, but our polymers were just not meshing with it very well, plus we had one hell of a flammable product (which by the way is what started this thread…correct?). Then I get a call from a defected Dupont fluoro chemist. He says IPA. Friggin rubbing alcohol. He formulates both a fluorosurfactant and a fluorpolymer based on fluorinated acrylic and IPA. We now have a water-based product that act like a solvent-based. Flash? Yup! As good as heptane, toluene and such? Nope! But again, good enough. Remember, this is sub-surface folks, we don’t need a bullet-proof coating, its not our bag. Plus, its up to the surface you are applying this to, to take the brunt end of mechanical abuse. You can always coat the surface to protect it from this stuff, but then what the hell I am doing banging my head on the wall over this??

So…we have the great fluoro technology adapted to water-based formulation, but surface tension is still an issue. We have here this great stain resistant product, but cant get it to penetrate some surfaces as well as we know they can. We add a basic surfactant to the mix. You know, make water wetter. Bingo. But you remember that Lone Ranger Chemist I mentioned? Yup, not good enough for him. We now venture into fluorosurfactants. He makes up some craziness that brings down the surface tension of our water-based products to less than 10 dynes/cm3. Great! Cost? Not so great! Remember that $1000 a gallon jug stuff I mentioned earlier? Yup. Plus I could not keep the shit in a bottle for the life of me, it just evaporated through the side of my jug. And these jugs are fluorinated themselves, class 4 even! There is another story behind jug fluorinating and pieces of granite and marble blowing up. For those reading this far, if you ask, I will tell. Well, enough for now.J

JC

1. You have to read between the lines to figure a ballpark for this. Stone Tech Pro (hi Karen) actually advertised their surface tension on the label. Old solvent-based technology with heptane in it is a low surface tension product. Think all the expensive impregnators here. Water-based fluoro products will run with the best of them.
2. There is a relation between density and surface tension. Old rule of thumb was solvent on anything polished. Not only because of surface tension (energy) but it was more applicator friendly. Easier to buff off, and when in a jam, dip your rag into more impregnator and buff haze right off. But we are not dealing with the same kind of resins. Some fluoropolymers require a good washing with water, not only to remove the haze, but also to activate it. The lemon test is great! It is not feasible to know the true density of every stone, not to mention this density changes depending on finishing techniques, such as polishing. Remember our conversation of deflection and natural stone, this is even worse.
3. Impregnators can benefit dense stones, such as absolute black. But we have to be reasonable too. If we have an impregnator with a surface tension of less than 20, and the stone does not want to take it in, well then there is not a hell of a lot out there that will stain that stone. I have formulations that will go right into these stones with no problem, but again, why?
4. I don’t know. Polished, honed, flamed, brush hammered or what? What is the actual density of that particular absolute black you are looking at? What are the environmental conditions during application? Deflection and stone again Through testing, I have had great success in the neighborhood of 15 dynes/cm3. But again, what is the point? Not much is going to stain that granite to begin with.


I don’t want this technology to sound like a cure all though. Marbles will still etch like a SOB. So as far as acid etching goes…well…still at the drawing board

[John Bridge]

kemguru
Restoration Specialist

Registered: Nov 2002
Location: Denver, Colorado
Posts: 264
Through research, and I am not wanting to try to set a standard here (although it could very well be one) 19 dynes/cm3 is about the lowest solvents will go. Some surfactants work is a solvent system, and actually bring it down lower, but those damn VOC regs again. Why should I invest more time and money into solvent technology? The water-based technology has successfully penetrated very dense surfaces once we hit 16 dynes. So, anything 16 or below will work its way into most any dense surface.

ASTM? Hahahaha Proprietary information? If a formulator were to read my posts so far, they damn near could match what I have been working on. But they would not have as much fun as I have had.

“Breathability” (according to Word this is not a word ) has nothing to do with stain resistance. Remember my piece of SILK I mentioned earlier? Now, on an extremely pourus surface you will see “staining”, but this is more of a mechanical issue. The contaminate is just sitting in the pores of the surface. Vapor transmission is a two-way street; this is why we see a faint shadowing when a fluoro-protected surface gets wet. This is only surface wetting, it evaporates real quick. This is the hardest sell with this technology. People want to see a dramatic beading affect, which it does provide, but you see a slight fogging. Even silicones don’t provide that great of a beading affect until you add wax to the mix. Yup, wax. Talk about clogging pores. Now, if we start talking film formers vs. impregnators, well, impregnators lose. I can’t touch a polyurethane coating as far as resistance. But go ahead and “cap” that stone with poly and see what happens.


Good fun everybody, good fun

[fhueston]

Stone Impregnating Sealers are not Bullet Proof
By Frederick M. Hueston

I receive several calls a week with questions on the use of impregnating type sealers for use on outdoor stone as well as interior wet areas such as showers, water fountains etc. The question is simple: Should I seal my stone in these conditions. The following article will provide a reason why stone in wet areas should not be sealed.

Before we discuss the reason why we shouldn’t seal stone in these conditions a few definitions are necessary.
Impregnators or penetrating sealers: Impregnators are designed to penetrate below the surface of the stone and deposit solid particles in the pores of the stone or to coat the individual minerals below the surface of the stone. Water, oil and dirt are restricted from entering the stone. Impregnators can be solvent, or water based. Most impregnators are vapor permeable.
Vapor Permeable: breathability, vapor permeability describes a stones ability to allow water vapor to pass through it.

The case for not sealing stone in wet environments
When stone is exposed to unregulated humidity and temperature fluctuations, as it would in an outdoor environment or in a shower, the air contains vapor in what we know as humidity. Temperature along with humidity can result in condensation as well.
Most of the impregnators on the market today are breathable. This simply means that the stone will be protected from water entering the pores of the stone in liquid form but will allow water vapor to pass.

In wet environments vapor can be present for several reason, rain, high humidity, temperature fluctuations, steam etc. Since these impregnators are breathable, this vapor can easily penetrate into the stone. One would think that this is a positive. The fact is that once the vapor enters the stone it can condense and become a liquid. Since impregnators protect against water in its liquid phase it becomes trapped within the stones pores and will not escape until it evaporates or in other words turns into a vapor. Once this water becomes trapped it can result in all kinds of problems. Stones with iron content can begin to oxidize, natural salts with in the stone can become dissolved and cause pitting and spalling. Aesthetically the stone will appear darker since it is constantly wet.

This problem is becoming more of an issue with the increase of stone being used in showers and exterior environments. There are currently several people doing experiments demonstrate that sealer in wet environments can cause these issues. I strongly believe that care should be taken when sealing stone in these wet environments.