A couple questions regarding CPES

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DSR
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A couple questions regarding CPES

Postby DSR » Wed Aug 17, 2016 3:28 am

Hi everyone, I'm planning on getting started on my build very shortly and I'd like to get some clarification regarding CPES and if it's something that I should use....
If I'm thinking correctly, and please correct me if I'm wrong, I could actually apply this to the individual parts before I glue and screw and it will help with strength of the the epoxied assemblies (such as the frames and transom, planking etc.)? And I also plan on finishing the complete interior of the hull with a catalyzed urethane auto paint. From what I've gathered, it sounds like once the interior of the hull is completely covered by the CPES it does the job of epoxy-encpasulation and painting directly over the CPES would be a good way to go or am I reading this wrong? Any help from those who have used this product would be greatly appreciated!!
Thanks
Dave
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hoodman
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Re: A couple questions regarding CPES

Postby hoodman » Wed Aug 17, 2016 7:04 am

I don't have any experience with CPES and am just planning on encapsulating the inside of my boat with regular un-thickened epoxy. Best practice is to coat any pieces to be glued together with a thin coat of un-thickened epoxy and allow to soak in for a few minutes before applying thickened epoxy. Plywood especially will soak up a little bit of epoxy and you don't want it to wick too much out of your thickened mix.

DSR
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Re: A couple questions regarding CPES

Postby DSR » Wed Aug 17, 2016 8:55 am

Hi Matt, thanks for your time. This is something I stumbled into while I was searching the forum for tips and tricks (which there are a ton of). From what I've read so far it looks like most people are using the CPES on new builds as both a "sealer" for the wood and as a "primer" for epoxy glue-ups when assembling and getting mostly positive response (other than the fumes of course). If this is in fact true, I was wondering since I'll be finishing the inside of the hull with an automotive urethane primer / paint system and Smith's is stating that the product accepts paint and varnish very well, would epoxy-encpasulation after the CPES would be redundant or if there's a benefit to doing both before painting?
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hoodman
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Re: A couple questions regarding CPES

Postby hoodman » Wed Aug 17, 2016 9:55 am

I'm guessing it is redundant. CPES is epoxy itself after all. I believe with some extra solvents than normal epoxy to help it soak into the grain a bit better. Someone that has used it will chime in. Most paints you will still need to use the primer that goes with their system.

gdcarpenter
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Re: A couple questions regarding CPES

Postby gdcarpenter » Wed Aug 17, 2016 1:38 pm

In terms of full disclosure I have not used CPES.

My understanding is the quality and effectiveness varies brand to brand. As I understand it - it is, in and of itself, NOT an 'encapsulating' product, ergo NOT designed to be your first line of defence against water intrusion.

Methinks it was first developed to stem wood rot, so it's 'thin' and penetrates. As an adjunct to a true encapsulation with epoxy it provides a 'back up' should water penetration occur.

Personally I would not rely on it as my first line of defense.

I do not see it adding any strength in any way.

Always follow manufacturers recommendations as to base coats for paints.
This is my first, last and only boat build.

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DSR
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Re: A couple questions regarding CPES

Postby DSR » Wed Aug 17, 2016 8:14 pm

Hi Gd, thanks for stopping by.
I was wondering if I was wrapping my head around this CPES thing correctly or not. With this being my first build I wanted to explore all the different options to build a fun, fast little boat and make it as safe as I can along with making sure she sticks around for a long time.
I appreciate you guys taking the time to help me and using that I believe that I will be encapsulating the interior to get the protection and the base for finishing. With that in mind, is there really a benefit to using the CPES in a new build or is it unnecessary money and time spent? I will be using the 2K urethane paint with an epoxy primer which has worked very well for me on previous projects

Thanks guys!
Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
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bjfrater
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Re: A couple questions regarding CPES

Postby bjfrater » Wed Aug 17, 2016 9:34 pm

Like Gd said, Some guys apply a coat of CPES to wood prior to encapsulating with epoxy.
I spoke with the guys at Westsystem who's epoxy I use and they said that it was unnecessary as they believe their product does the job without it.

I think its up to the builder, if your boat is gong to sit in the water permanently and you are worried about the quality of the epoxy then maybe you would use it. I personally decided against it after the advice I got plus trying to avoid extra contact with dangerous chemicals as much as possible.

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hoodman
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Re: A couple questions regarding CPES

Postby hoodman » Thu Aug 18, 2016 7:36 am

bjfrater wrote:Like Gd said, Some guys apply a coat of CPES to wood prior to encapsulating with epoxy.
I spoke with the guys at Westsystem who's epoxy I use and they said that it was unnecessary as they believe their product does the job without it.

I think its up to the builder, if your boat is gong to sit in the water permanently and you are worried about the quality of the epoxy then maybe you would use it. I personally decided against it after the advice I got plus trying to avoid extra contact with dangerous chemicals as much as possible.


I agree with all of this. I honestly don't see how CPES can really soak into wood that much more than just some regular good quality marine epoxy. Maybe if there is rot or the wood is a little soft there is a benefit to it. From my experience okoume and meranti plywood soaks up regular epoxy quite readily. The first light coat soaks in and you get sort of a fuzzy finish. Then a light sanding and your second coat smooths everything over. You'll want to put it on as thin and smoothly as you can because epoxy doesn't level itself very well like a good paint. The Yellow rubber scrapers are a good way to apply thin coats to large expanses of plywood.

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Bill Edmundson
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Re: A couple questions regarding CPES

Postby Bill Edmundson » Thu Aug 18, 2016 7:49 am

I agree with Matt. I tried CPES and regular epoxy on the same piece of wood. When I cut the wood I didn't notice a difference in penetration.

On bad wood, I'd CPES first.

Bill
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DSR
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Re: A couple questions regarding CPES

Postby DSR » Thu Aug 18, 2016 9:09 am

Perfect guys!! Thanks so much for your help!
That confirms my decision to just encapsulate with a good epoxy. The boat is only going to be in the water when it's being used so it should outlast me at least :D
Thanks again and I'm sure I'll be back with more questions and also updates and pictures as I go
Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
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