CPES and coating before or after..

[Shazza]

Okay... I have a question My intention is to coat every surface of wood with CPES as long as I can buy it before it is all gone.. If I coat my 1/8 inch ply with CPES before installing on the curve of the roof.. will it be more likely to crack? or should I install it first and then apply it? also how many coats of CPES should I apply over all to have the optimum protection?

And is there anything else that will work comparable to CPES?

Thanks Guys & Girls.....

Shazza

[doug hodder]

Shazza....If'n it were me....I'd put the top on and then do the top coat. I personally don't think that it needs to be encapsulated with the CPES on the interior side. Others opinions may vary. On a boat, it is important to seal the inside hull walls as there is going to be a fair amount of water that can get in there and would eventually lift the outer coating and rot the hull from the inside out. On a tear, I don't think it's necessary as it won't have that amount of water or moisture on the inside. There is nothing wrong in completely encapsulating it, a very good selling point in the future maybe, but might be overkill. I have insulated ceilings and that will also help cut down on the potential moisture issues.

As far as cracking issues, I don't build using CPES, just epoxy so don't know the specifics on how it would react or potentially stiffen the material prior to install. I put the wood on, then do any coating afterwards. Like I say...just my opinion. Doug

[Miriam C.]

CPES is a wood hardener I think. It was originally intended to harden rotted wood on boats so they could be restored. It might make your ply hard to bend. The good news is you can call Rot Dr and ask for your type of ply. They are familiar with what we do.

If you use CPES, you will want to cover your hair and body really well to put that on over your head and use a respirator and fan for fresh air. It really shouldn't be used in enclosed spaces.

Good luck. Oh and you might look into Steve's manual. I am sure he covers the use of CPES.

[Boodro]

Ahhhh..... doesn't the E in CPES stand for Epoxy???? I plan on using it for my next build. the best place to ask a question is the Rot Dr. like Aunti m said. Good luck!

Let us know what they said so we know too!

[doug hodder]

Good point Boodro...the E does stand for epoxy...but there is a difference in the CP..."clear penetrating" as opposed to a straight epoxy, they aren't the same critter. I guess it comes down to using whatever you are comfortable and familar with. I like a straight epoxy as there are a lot of additives that can be dumped into it for whatever your needs are, fairing, structural, top coating etc...Doug

[cuyeda]

Okay... I have a question My intention is to coat every surface of wood with CPES as long as I can buy it before it is all gone.. ...snip... snip...
Shazza

"buy it before it is all gone.." Did I miss the announcement from Rot Doctor? Is the CPES product going away? Not trying to hijack the thread, but the Uniflex product by Rot Doctor was being discontinued last I heard. Is CPES also being discontinued?

Shazza,
I have read that epoxy can be thinned with mineral spirits and applied similar to CPES. I have not tried this method, and hopefully someone else will chime in. Good luck with your TD build.

[S. Heisley]

[quote]
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Shazza wrote:
Okay... I have a question My intention is to coat every surface of wood with CPES as long as I can buy it before it is all gone.. ...snip... snip...
Shazza


"buy it before it is all gone.." Did I miss the announcement from Rot Doctor? Is the CPES product going away? Not trying to hijack the thread, but the Uniflex product by Rot Doctor was being discontinued last I heard. Is CPES also being discontinued?


[quote]

No, CPES is not going away. When I got the message that Uniflex was being discontinued, I called The Rot Doctor the very next day! They told me that CPES is not affected by the new chemicals ban and will still be available next year.

Shazza: I would wait to put on the CPES until you have the roof in place.
CPES makes the wood really tough and hardens it to the point that it becomes harder to cut or to even drill a hole in. I'm pretty certain that putting the CPES on before you've curved the wood onto your frame would make it doubly hard to do. Also, I wouldn't be surprised if you had hairline cracks develop in the CPES'd finish just from the curving effort. Anyway, you'll want to CPES after you've drilled all your screw holes and made any brad/nail holes that might be necessary. If you don't, each one of those holes will be more vulnerable to water. The same goes for any cuts you make. Those are the most vulnerable places for water to seep in.

Thinking the wood would be made stronger, I made the mistake of applying two coats of CPES on my base plywood floor before I had cut it to fit. After that, it took three saws to get through the stuff and I actually bent the teeth on one blade. I had to finish cutting that piece with a hack saw.

Wishing you success!

[schaney]

I would install the roof panel before applying any finish to them. Bending plywood will put the outer surface of the curve in tension, this will cause mirco fractures in the wood. Not to worry this isn't a structural issue. The CPES will actually helps to seal them up.

It normally takes two coats to seal plywood. Ditto the apply it outdoors and ONLY while wearing a respirator.

IMHO CPES'ing your interior is overkill.

The company that makes CPES is actually Smith and Company, they do sell it direct. Their tradename for it is MultiWoodPrime

[S. Heisley]

...Forgot to answer one of your questions.

According to the CPES documentation, 3 coats of CPES will make a piece of wood waterproof. Less than that makes it water resistant.

[Shazza]

Wow... thanks everyone...

This was exactly what I needed.. I would have applied my coating before I put the top on or cut it out even.. and then again on the cuts and screw holes.. I guess if I'm not careful I could turn into one of those overkill people.. lol I just really want a light weight Tear that I can pull with my VW Bug or my Jeep Cherokee... eventually one for each.. I guess I really need to get started I've been lurking and researching for just about 2 years and signed up this last summer.. I'm just a little scared about starting! I really want something to camp in this next summer.. Time to "Get r' done!"

So Doug and those who don't... if you don't use CPES and just epoxy... how do you apply it? do you thin it down? Or apply it straight?

Thanks a ton!! I so appreciate this board..

[Steve_Cox]

This epoxy user mixes as directed, and not thinned. I roll it on with a West System foam roller. CPES is 4 parts solvent and 1 part epoxy, if I remember correctly. I bought some CPES recently, but when it is gone, I am going back to just using epoxy, I like the ability of the epoxy to encapsulate the wood with one coat. CPES after all was developed to restore rotten wood. After using it, I find it would be excellent for restoration uses, but I feel I have better results with plain epoxy. Also as Doug mentioned, epoxy with different fillers added can be an excellent adhesive or it can be used for fairing seams, holes and rough places.