Teardrops n Tiny Travel Trailers

Has anyone used CPES under regular Epoxy?? Does CPES build up to a shiny finish after more than 2 coats? I was thinking of using one coat of CPES to absorb into the wood and then finishing with Epoxy then Varnish. This if for the walls and roof and not under the floor, where I have already sealed with Asphalt Emulsion.

alftinc wrote:Has anyone used CPES under regular Epoxy??

Yes.

alftinc wrote:Does CPES build up to a shiny finish after more than 2 coats?

No, on baltic birch plywood.

alftinc wrote:I was thinking of using one coat of CPES to absorb into the wood and then finishing with Epoxy then Varnish. This if for the walls and roof and not under the floor, where I have already sealed with Asphalt Emulsion.

This should work, although I have no experience with the varnish part.

Hello. I'm Steve Smith. I invented CPES back in 1972. My customers have told me of the results they have had over the years; a lot of things that worked, and some that did not. My application notes and product literature are based on all that, as well as my own lab work.

The application notes are here:

http://www.smithandcompany.org/technical.html

The top one is an article I wrote for the Amateur Boatbuilding website. The companion piece, "Priming with CPES to glue down the varnish", is the second half of the story.

Please read those two, and if you have any questions, feel free to phone or email, or post anything here.

Steve Smith

Steve, welcome.

"Priming with CPES to glue down the varnish" is a great saying and I'll trade you another from my former wooden boatbuilding boss: "Epoxy resin is varnish that can be applied four to six coats at a time."

Andrew

Thank you for that, Andrew, but I will have to take issue with you on the use of epoxy resin as if it were varnish.

Varnish, a coating made from the oilseed resins of various plants, has a certain degree of stability against ultraviolet. The most flexible of them, Epifanes Gloss, has more flexibility than the wood it is laid upon. The easily available rock-hard fast-curing epoxy products contain both aromatic rings which readily break on exposure to ultraviolet, and amines which promote yellowing on ultraviolet aging. They cannot contain ultraviolet absorbers as do varnishes, for the amines turn the ultraviolet absorbers bright yellow for technical reasons.

There's an article I wrote some years back for a painting magazine that explains the underlying technology of all clear finishes. It's posted on one of my websites, here: http://www.fiveyearclear.com/CCOW.html

Steve Smith

Steve,

Welcome to the forum.

I'm sure Andrews quote from his at one time boss "Epoxy resin is varnish that can be applied four to six coats at a time." was meant as a tongue in cheek comment, not to be taken literally.

It is nice to have manufacturers take an interest in our little trailer building obsession. Are you planning a small trailer perhaps?

Rot Doctor products have been widely commented upon here for several years, and occasionally your products have been mentioned as well. Hope you stick around so we can all learn from your experiences.

Steve, you might also want to visit here http://www.mikenchell.com/forums/viewforum.php?f=40

alftinc wrote:Has anyone used CPES under regular Epoxy?? Does CPES build up to a shiny finish after more than 2 coats? I was thinking of using one coat of CPES to absorb into the wood and then finishing with Epoxy then Varnish. This if for the walls and roof and not under the floor, where I have already sealed with Asphalt Emulsion.

Al,

As to the specific answer to your question about what happens after 2 coats of CPES, I know that when I applied a 3rd coat of it on luan plywood it did start to have a smooth shiny finish. I think your plan will work fine.[/url]

Steve_Cox wrote: I'm sure Andrews quote....was meant as a tongue in cheek comment

Quite right: though like all quips there's an element of truth in it - when my boss switched from using just varnish on boat decks to varnish-over-epoxy, this was how much they reduced the number of coats of any product to be applied. When they finished decks with just varnish (1960s and before), they really did apply over 20 coats to get the standard of finish discriminating buyers expected.

But, yes, I do recognise the very different purposes for which epoxy and varnish layers are used.

Steve, the articles you quote are fascinating - as always it's a treat to hear an expert explain things.

One question I'd be interested to hear your opinion on is whether you consider it a good idea to thin the first coat of epoxy with a volatile solvent - I was taught this was bad practice, but there are plenty of others who believe it's good practice.

Andrew

The Clear Penetrating Epoxy Sealer contains solvents which dissolve both the moisture in the wood as well as its saps and resins, and also the water-repellent resins that I use. It is NOT a glue for anything except microscopic wood fibers, neither a fiberglass layup resin, as most other marine epoxy products are intended.

I use resins that are "epoxy", but of an utterly different kind from the "epoxy resin" materials used by all other marine epoxy merchants. The kind of resins I use will have a toughness and flexibility comparable to that of the original wood. Those other kind of resins just don't. The reason I use what I do is because I want the treated wood to have similar mechanical properties to natural wood. If you look in Section Three of www.woodrestoration.com you will see mechanical tests that prove the untreated wood and treated wood bend in almost an identical manner, although the treated wood is actually stronger, by an average 41%.

No other epoxy product, thinned or not, behaves that way, much less has a working time after mixing, of many hours. You can see that for yourself in any test you wish. I do not believe that an impregnating primer which should glue down a flexible topcoat, should be much stiffer than the wood.

The solvent system is a rather sophisticated one, in that it needs to dissolve mutually incompatible things: The water-repellent impregnating resins and wood resins, and the natural moisture in the wood. There were some experiments done on The Wooden Boat Forum some years back, that showed that a common hard epoxy, thinned with alcohol and then some water added, to represent the natural moisture of wood, actually separated into the water-soluble curing agent and the water-repellent liquid epoxy resin. That means that a common marine epoxy, used that way, has a good chance of demixing inside the wood, and never curing.

There's actually quite a bit of science involved in my products, to make things that work under the adverse conditions that are found in boat applications. That's why they work so well in architectural applications and on sound wood such as wood trailers.

Steve Smith.

I don't mean any disrespect, I really don't. I have read plenty on this board about how many people recommend this product but it is ungodly expensive. It really concerns me as I have no idea how much I would even need, the site has coverage at 20-200 sq feet? With a 4.5'x10' teardrop coating both sides of the wood and a roof I am looking at somewhere in the area of 250-300 sq ft. That could use anywhere from 2-10 gallons at $400-$2000. I have no doubts that it is a great product but if I am skinning my teardrop with aluminum isn't treating the wood underneath that aluminum really just in case my seals/joints fail? Wouldn't painting that plywood underneath the aluminum do almost equally as well with a good primer/paint at about $75? I am not one to cut corners because of cost, I really do believe in doing it right once but I have looked at Smith and Company's website probably 10 different times and every time I run away in shock if this is something I will really need. Since the aluminum floats over the plywood adhesion isn't an issue, the CPES (if my understanding is correct) for my teardrop is just a backup. I can see this on a boat where the wood is being soaked in water but as a protection under plywood for a teardrop isn't this really extreme?

Sorry, I don't mean to be "that guy" and I am not trying to say your product isn't worth the money for the right application but for a teardrop (the way I am using it anyways under aluminum skin) isn't this overkill as an under the aluminum undercoating?

On new plywood the coverage will likely be 200 square feet per gallon, maybe even more than that since you are using high-quality plywood, and not stabilizing old wood. You may even see 400 square feet per gallon...it really depends on the wood.

There will inevitably be condensation behind that aluminum skin, and water will accumulate there, and open the door to rot issues. Clear Penetrating Epoxy Sealer isn't the total answer, but for thirty years it has helped wood resist deterioration from Small Life.

I recently invented something new, and today if I was building what you are (or most anything of wood that sees weather or condensation), I would use the Wood Vitality www.fresher-treated.com first, and Clear Penetrating Epoxy Sealer second.

I understand about the sticker-shock...most of the Smith & Company customers are restoring somewhat deteriorated wood, and coverage really does range down to 20 square feet per gallon or even less, but when looking at the replacement cost of fascia or window-frames it is still a practical solution.

I hope that helps put things in perspective...

This helped me a bunch. I'm new around here gatherin' info for a future tear build. A couple weeks ago I wasn't sure what CPES was. Now the guy that invented the stuff is explainin' things. Thanks
Smokey

Steve Smith wrote:On new plywood the coverage will likely be 200 square feet per gallon, maybe even more than that since you are using high-quality plywood, and not stabilizing old wood. You may even see 400 square feet per gallon...it really depends on the wood.

There will inevitably be condensation behind that aluminum skin, and water will accumulate there, and open the door to rot issues. Clear Penetrating Epoxy Sealer isn't the total answer, but for thirty years it has helped wood resist deterioration from Small Life.

I recently invented something new, and today if I was building what you are (or most anything of wood that sees weather or condensation), I would use the Wood Vitality www.fresher-treated.com first, and Clear Penetrating Epoxy Sealer second.

I understand about the sticker-shock...most of the Smith & Company customers are restoring somewhat deteriorated wood, and coverage really does range down to 20 square feet per gallon or even less, but when looking at the replacement cost of fascia or window-frames it is still a practical solution.

I hope that helps put things in perspective...

That's a pretty sparse website! What is the cost of that stuff?

Kerry

The price is listed on the webpage.

The two-gallon kit costs $100.00 delivered anywhere in the 48 states.

Endo wrote:Kerry

The price is listed on the webpage.

The two-gallon kit costs $100.00 delivered anywhere in the 48 states.

My bad! Just can't read too good, I guess!