Clear Penetrating Epoxy Sealer as a "primer" for teak?

[Beausoleil]

At the end of the thread "Repair and Fill for Large Teak Crack, someone suggested using Oak & Teak Epoxy Glue for repairing a crack in teak lumber.

While checking out the link, I found the a reference and link to Smith & Co.'s Clear Penetrating Epoxy Sealer and its use as a "primer" prior to topcoating teak. The manufacturer claims that it "discovered when CPES was used for wood restoration: CPES was functioning as a high grade adhesion-promoting primer as well, and the paint/stain/varnish topcoatings that had been applied were not failing within the expected time frame. Therefore, after restoration was complete, general maintenance costs were cut in half."

We're getting ready to use Bristol Finish, the 2-part epoxy with UV additives, for our brightwork and am now contemplating using CPES as the base coat. Has anyone used CPES as a base for varnish/polyurethane/epoxy, and were the results as expected? We've had 12 coats of varnish done according to "varnish queen" Rebecca Wittman's methods, yet had it start deteriorating in 6 months in the Caribbean sun. We're now in the mid-Atlantic region, but I don't want a repeat of that - I'd love to see 10 years with a bit of as-needed maintenance.

[bletso]

I use it as a base for varnish and Cetol. The beauty is you do not have to use a thinned coat of varnish as a seal coat, the CPES does it. It is the consistency of water so it will soak right in. BTW, if you have questions just email them and my experience is they will answer quickly.

[Jason Flare]

Can anyone comment on whether CPES would be a good primer on bare teak prior to topcoating with paint?

[TeddyDiver]

Originally Posted by Jason Flare

Can anyone comment on whether CPES would be a good primer on bare teak prior to topcoating with paint?

Nope! CPES is a hoax.. and teak being oily wood needs oil wiped of with acetone if using any epoxy based coat.

BR Teddy

[phorvati]

This year i used CPES as first two coats on my teak cockpit table. It feels very nice. Yes teak is oily, but if you are dealing with old weathered teak and partly peeling varnishes, you have to sand the surfaces. To get the old stuff off, you are probably going to sand with 40 or 60 grit. Sanding gets rid of the surface oils. Its only been two months but i know that the same cockpit table needs to be done every 4-5 years. So i will find out if CPES made the job last longer than usual. I do the same with combings dorade boxes and other exterior teak surfaces. I got around to doing companion way steps as well which needed it badly. Ended up doing the same. Because so much dirt and grease has accumulated on the stairs, i ended up sanding it with 60 grit, and worked my way to 220grit. This gets the teak smooth to the touch. CPES penetrated and sealed it very nicely.

[bletso]

Originally Posted by TeddyDiver

Nope! CPES is a hoax.. and teak being oily wood needs oil wiped of with acetone if using any epoxy based coat.

BR Teddy

And your source for this information is? Contrary to your belief, I have had very good results with CPES and their Teak glue/epoxy. I have been using it for four years now.

[Stumble]

Originally Posted by bletso

And your source for this information is? Contrary to your belief, I have had very good results with CPES and their Teak glue/epoxy. I have been using it for four years now.

Anyone and everyone who has any knowledge of epoxy chemistry. Hundreds of forum threads detailing the problems with it, governmental action taken to shut down advertising. Scientific testing of the product in action... This isn't a debate anymore it is an absolute fact. CPES and its ilk are an expensive hoax.

If you want to seal wood use three coats of 100% solids epoxy.

CPES and its ilk take decent epoxy to start, then add solvents to thin it. In the best case as those solvents evaporate it leaves pin holes in the epoxy that destroys any water proofing effect. In the worst case the solvents prevent the epoxy from forming the chemical bonds necessary to fully kick and you have a goopy mass.

Add in that CPES is roughly five times more expensive than a name brand good epoxy I fail to see the point.

[Panacea2183]

Always wanted to try the penetrating epoxy as a primer!
Sold the boat before I had a chance.
Have new boat that needs varnish work so will be considering
The present boat has been re varnished several times and is not in bad shape but it's time for a complete strip re-stain and re-varnish.
Been redone too many times and not soon enough so repairs are obvious.
Have done this before and it brings back that new teak look (nice dark color)

I did use Bristol Finish ONE time, man did it look great nice hard finish nice dark color looked like new!
6 month later started to fail around any joint and bungs, stantions.
Did tons of prep work followed directions etc. Not a new bee to refinishing, still have a 1965 wooden Chris Craft 22' Cutlass (for sale by the way owned since new needs to go)
When came time to repair the Bristol Finish it was a bitch! Very hard to blend color almost impossible to remove.
May have done something wrong but went to Cetol. If you can stand the color and the not showroom look the your in very easy to maintain.
In the tropics varnish is only 4 months away from failing but easy to repair
At some point any teak finish will be due to be stripped and re done.

[phorvati]

Cpes is probably just the thinned down version of epoxy. I had some spare and that was primarily why I used it. I would agree that you could get the same effect with thinned west systems epoxy.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[chris95040]

Originally Posted by Stumble

In the best case as those solvents evaporate it leaves pin holes in the epoxy that destroys any water proofing effect

They are suggesting using it as a primer.... So the "waterproofing" of the CPES coat is irrelevant.

When used as a primer, and the solvents have an opportunity to evaporate off before it cures and before you apply your topcoats, then I don't have a problem believing it penetrates a little better than straight epoxy. But honestly, you might be right, it might be snake oil.

In my actual experience, I used CPES on my teak cabin trunk as a primer for a clear two part polyurethane (Bristol Finish). I did it on recommendation from a sistership owner who claimed he would get 5-6 years of maintenance-free life, at which point he'd scuff it, apply a couple more coats of bristol, and get another 5-6 years out of it.

That sounded good to me so I tried it. I'm on year 3 and it looks spectacular.

Because I'm a man of science (actually, a man of disorganization who forgot to buy more CPES) I tried another section using west system as the primer. Straight west, after wiping down the teak with solvent. Then proceeded with the Bristol finish 2 part poly as before. The wood ended up _WAY_ darker than the beautiful, honey colored sections I did with CPES as the primer.

I dunno, I'm skeptical, and the dude who makes CPES is a frigging NUTCASE, but count me as one vote for CPES + 2 part poly.

-Chris

PS - when used as a "rot doctor" or whatever, I think it's probably terrible. Without letting the solvents evaporate, you'll get a gummy, then later, brittle, garbage cure. There is a neat product from epoxyproducts.com, their "Low-V" epoxy. It has no thinners, it's just a straight resin that has been manufactured at a really low viscosity. It still has like 2/3rds the tensile strength of straight West, if I recall. I think if you want penetrating action, that's probably the product to use.

And one final point - I tore up some deck which necessitated redoing some varnish on previously CPES + Bristol 2PP finished cabin trunk. I was always afraid the "heat gun + flat blade scraper" would no longer be an option once I went to this system, but it all came off just like old timey varnish. No worries there.

[Lepke]

I had a yard and did varnished exterior wood as part of bigger jobs. I use West Systems epoxy with special clear hardener. On new wood I used two coats with light sanding in between coats followed by 3 varnish coats that had uv blockers. Clients (and competitors) thought we were doing a dozen coats because it looked as good. With any varnish or varnish substitute, it's good to light sand and recoat every year to keep the deep varnish look. I also use MX-3 that is clear an mixes in almost every paint and varnish to kill the green stuff that grows in damp climates.
I painted the varnish on this boat.

[katoosh525]

Originally Posted by chris95040

PS - when used as a "rot doctor" or whatever, I think it's probably terrible. Without letting the solvents evaporate, you'll get a gummy, then later, brittle, garbage cure. There is a neat product from epoxyproducts.com, their "Low-V" epoxy. It has no thinners, it's just a straight resin that has been manufactured at a really low viscosity. It still has like 2/3rds the tensile strength of straight West, if I recall. I think if you want penetrating action, that's probably the product to use.

Chris, for the rot doctor repairs, I can confirm that it sets rock hard, travels right through rot, and gives you large sections of timber that are harder than the original. You do use a lot, but it is very effective used like this. I don't know what they have done, whether it is clever catalysts, or the solvent blend, but it does set hard when used to treat massive sections of rot in large timbers. My house has many timbers 6" square and up that I have treated like this, very successfully.
I know what you are worrying about, as I tried the SP product for this purpose (not that they even claim you can use if to this of course), and that did set very gummy when used like this, but the CPES set rock hard. Try it one day. If the Low-V travels through wood like CPES it would be worth a comparison, but it would have to go some way to travel through rot like CPES does.

[Mithril Bham]

Used West Systems as primer then 3 to 5 coats of varnish as recommended by someone with a lot of experienced. Worked great. Don't know about epoxy.
A lot of schools of thought on this subject.

[dagranger]

Having had some experience with teak and varnishes I would always keep in mind what ever you put on you will eventually have to take off..On a recent experience of Hans Cristian 43 with coats of something called honey etc.epoxy of some sort..all had to be taken off took forever we then applied several coats of teak oil..looks terrific once a year clean not with stiff brush as it will take all the soft wood off and leave the teak looking like ridges which needs to be sanded..depending on climate clean and reoil. If cleaned with good teak cleaner you will not have to scrub at all..good luck!:

[Stumble]

Originally Posted by katoosh525

Chris, for the rot doctor repairs, I can confirm that it sets rock hard, travels right through rot, and gives you large sections of timber that are harder than the original. You do use a lot, but it is very effective used like this. I don't know what they have done, whether it is clever catalysts, or the solvent blend, but it does set hard when used to treat massive sections of rot in large timbers. My house has many timbers 6" square and up that I have treated like this, very successfully.
I know what you are worrying about, as I tried the SP product for this purpose (not that they even claim you can use if to this of course), and that did set very gummy when used like this, but the CPES set rock hard. Try it one day. If the Low-V travels through wood like CPES it would be worth a comparison, but it would have to go some way to travel through rot like CPES does.

It may harden but it doesn't have any strength. Molten glass will also harden, but I wouldn't trust beam made out of it.

ANY epoxy will penetrate a pourus substrate, CPES because of its solvents does penetrate a little deeper into wood, about 1 mill deeper than a 100% solids epoxy, but once it's there then what? Take a look at the mechanical properties sheet for CPES and compare it to any other epoxy on the market... Oh wait you can't because unlike any reputable manufacturer they refuse to publish mechanical properties data on it.

Third party tests however indicate that CPES is roughly 40% or less the strength of a decent epoxy, and costs significantly more.

If for some reason you really want to use epoxy in a way inconsistent with every chemist and reputable manufacturer, then just buy a good one and add a bunch of acetone to it. Same thing, but much cheaper.

That 1m difference in penetration btw is about the same as warming the substrate by 10 degrees F.

CPES was originally intended to repair damaged architectural wood like trim and cosmetic elements and if that's all you are doing it is a reasonable though expensive way to do so. But as any type of structural repair it is a fundamentally flawed product because it trades mechanical properties for marketing sizzle. The viscosity of epoxy has almost zero effect on the depth it penetrates, but adding solvents massively undermines its strength.