Osmosis with epoxy.

Pauloman, you can 'stand' on what you like, but you should also know what you are talking about. I will quote one well known location on the subject.

http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

"A question frequently posed to our technical staff is "can I thin West System epoxy so it will flow or penetrate better?" The answer to that question is "yes, but not without consequences." Many of the advantages of thinning epoxy are offset by disadvantages in other areas of epoxy performance.

Thinning epoxy means lowering its viscosity. Low viscosity epoxy flows better, is easier to roll or brush, saturates fiberglass fabric quickly, and penetrates more deeply and more easily into porous surfaces like partially rotted wood. There are two methods of temporarily thinning epoxy. One is to heat the mixture and the other is to add solvent to the mix. The goal of both methods is to reduce the epoxy's viscosity. This article explains what happens to West System epoxy when it is thinned either by heating the components or adding solvent to the mixture.

Through knowledge gained from our comprehensive test programs and from 30 years of practical experience, we have learned that epoxy formulation is a balancing act. When one characteristic is altered-e.g. changing handling attributes by adding a volatile solvent-other characteristics like moisture resistance and strength are also changed. Our chemists formulate a well balanced, versatile epoxy that provides excellent structural strength and moisture resistance. If you elect to modify it, you become an epoxy formulator and need to understand the effects of your changes. Armed with the information in this article, you can decide if thinning epoxy is worth the tradeoff in performance.

Is thinning necessary?
There is a perception that epoxy needs to penetrate deeply into wood to be effective. Sometimes this is true, but most of the time it is not. Some common misconceptions are that deep penetration of epoxy 1) makes rotted wood as strong as new, 2) increases adhesion, and 3) makes wood more waterproof. The following is a brief discussion of these points.

1) Rotted wood impregnated with epoxy does not make the damaged wood as good as new. Deep penetration of epoxy into rotted wood will make the wood hard but it will not restore its original strength. This is not important if the rotted material is non-load bearing. A rotted door threshold does not need to be strong, just hard. However, when the wood fiber is damaged, wood loses its ability to carry loads and unless the fiber is replaced, it will not regain its full strength. A rotted deck beam or sailboat mast needs more than epoxy consolidation to return the wood to its original load carrying capacity.

2) Adhesion in all but the highest density wood is not enhanced by deep penetration of the glue into the wood. Research performed at the Forest Products Laboratory showed that adhesion to birch was increased slightly by using thinned epoxy. In lower density wood species like Sitka spruce or Douglas fir, the weak link is the cross grain strength of the wood. It does not matter if the epoxy penetrates l/4" into the wood or 0.005". The strength of the wood, the amount of surface area and the adhesive ability of the glue determine the strength of a glue joint. Most types of wood glue do not penetrate deeply, yet, if used properly, they can exceed the grain strength. Epoxy is no exception.

3) Water resistance of a piece of wood is not enhanced by deep penetration. Wrapping wood in plastic makes a pretty good waterproof seal without any penetration at all. Likewise, an epoxy coating on the surface is more water-resistant than a thinned epoxy coating that has penetrated deeply into the wood because, in most instances, the epoxy thinned with solvent is porous."

 

The amount that epoxy penetrates into wood is pretty much imesurable, i did my own tests 40 years ago when the Gougeons first introduced their WEST (which stands for wood epoxy saturation technique) system was first introduced to satisfy myself that this was just marketting hype, i was of course relieved that it was just hype as the last thing i wanted was to saturate nice lightweight wood with heavy resin. We had already been using epoxy in the New Zealand boatbuilding industry since the 1950s with great results. I found that while it does migrate a small amount up the end grain 100% solids epoxy is effectivly just an outstanding coating on face grain that does its job just fine without soaking in. We also used a lot of a thinned epoxy product made by Epiglass called Everdure which is pretty much like the CPES which Steve Smith "invented" a few decades later which is great stuff when used in the right places. I have also tested it and CPES and while it may soak in a very small amount more it requires at least three coats because of evaporating solvents so is absolutly not a substitute for 100% solids epoxy to use in critical locations. Due to this evaporation of solvents from thinned epoxy products makes it very hard for me to buy into the marketting hype for International paints Interprotect "barrier coats, and other products of the same ilk but it seems to be what all the marinas are using here in the US. What do you guys think of these products?
Steve.

 

not sure why running a marine epoxy and industrial epoxy company and have epoxies formulated to my specs and sold around the world makes my obsolete. I probably deal with a dozen boat repair projects every single day, year in and year out. What are your qualifications regarding epoxy, epoxy forumulation and epoxy chemistry, Teddy?????

paul oman - progresssive epoxy polymers inc

 

Sorry ladies, I have to defend Paul. His epoxy is the best you can buy.
He knows what is talking about.
Lister

 

Paul,

Just out of curiosity do you have any studies by independent labs dealing with the amount that thinned epoxy penetrates into wood? As well do you have any studies showing the water proofing difference between standard epoxy and penetrating epoxy? As well as material standards including compression and strength testing for penetrating epoxy?

I am more than willing to revise my understanding of penetrating types, but so far all I have seen is opinion seeking to overturn existing science.

 

Regarding formulation and chemistry.. none. Regarding epoxy in marine environment +30yrs

What I have problem with is your statement..

Using epoxy as barrier coating means to protect wood against moisture so it doesn't expand anymore. And I've not seen yet good epoxy coating to crack by temperature changes..
And you know this thinning will work only with epoxy formulated solely for that purpose, and if you have, please show us some hard evidence that it's any better than regular marine epoxy without solvents..
The way you describe it could be used only as a primer under paint in single sided coating IMHO
BR Teddy

 

From your own pages Paul:

-Additives can be added to epoxies that make them less brittle, but generally at the loss or reduction of other positive epoxy properties such as chemical resistance.
-Epoxies are expensive, but there are ways to ‘water down' the epoxies with less expensive solvents an/or non-solvent thinners. These cheaper, diluted epoxies do not perform as well as the more expensive, unaltered epoxies. Diluted down epoxies are especially common with ‘floor epoxies'
-Adding a bit of solvent to a solvent based or solvent-free epoxy is something that most manufacturers would not officially approve of and something that might not work with all epoxies. However, it can be done (unofficially) with the epoxies I deal with. Adding solvent to these epoxies will: 1) thin them out; 2) increase potlife; 3) allows them to flow off the brush/roller a bit more smoothly; and 4) perhaps allows them to ‘soak-in', penetrate, or may be soften, the substrate just a little bit. Not change is visible in the epoxy unless 12% or greater solvent is added. With that amount of solvent, the epoxies no longer cure with a glossy finish.

 

Indeed Teddy - that ties in with the info from

http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

which I notice got completely ignored

 

My Teddy - aren't you a nasty little man. Not getting enough fiber in your diet? You seem to thing you are an expert but have nothing to prove it.

 

Yeah.. and doing nasty little remarks every now and then when someone tries to sell snake oil

That makes two of us

 

I wounder if only ONE of you had used Paul Epoxy?
Like old ladies at the hairdresser the Saturday, you just gossip about things you don't knows.
Use the product before giving your opinion.
I used personally 8 GALLONS of it, and counting, so please stop your stupids and ignorant attacks.
And for the brain dead who didn't find the price list, just get out of the forum, because what you said is a big LIE.
Paul is descent, and try to help. I am sorry for him to be surrounded by so much hatred and mostly IGNORANCE.
USE HIS STUFF AND THEN TALK OR SHUT THE HELL UP.
Enough of this tea party style of communication.
Shame on you all.
Lister
THE GUY WHO USE PAUL EPOXY.
No I don't know Paul, and I don't have stocks in his business.
I just know his product.
I repeat for the brain dead: PRODUCT.
Not literature or web-site.

You are just a pathetic bunch of naysayer for the sake of being important.
You all piss me off with you attitude against an honest business.

 

For the moderator

Moderator,
When people attack for no reason an honest business, just because they don't know what they read, but never used the product, you should intervene, and ask for real proof of their diatribes.
Lister

 

Agree that personal attacks and insults are not conducive to sharing knowledge or getting to the truth of the question at hand.

Please everyone let's stick to discussing facts and the topic at hand in a productive manner and not resort to personal attacks or insults. Thanks very much to those who are sharing information, test results, and articles to keep the discussion informational.

 

I am still waiting for Paul to substantiate the claims he made about thinning epoxy. Particularly when a manufacturer is making claims about his product I always prefer to see some testing that was done. And the claim that you can dilute epoxy by up to 12% before changes are visible is particularly troubling to me. I don't care what epoxy looks like, I want to see strength testing. And diluting a structural product until it is visibly different is a scary possibility.

 

Lister - it was nothing about his product, it was, as Stumble so succinctly put it - about the proposal that thinning epoxy was either necessary or a good idea.

I and numerous others have quoted why it usually isnt, while Pauloman got upset and made bad noises about Teddy, with no extra info to share.

As Mr Moderator so aptly said - lets stick with facts and information.