Thinning epoxy resin

[2DLake]

I am looking for some help with making my own thinned epoxy resin. I have read several things and have a general idea of what I want to do, just need some specifics.

I have read this: http://www.epoxyproducts.com/penetrating4u.html . Based on their info I am planning to use US Composites 635 epoxy and mix 40% epoxy to 60% xylene.

My questions are:

1. Has anyone used this mixture? How did it work for you? Pros? Cons? Better options or different concentrations.

2. When adding the xylene, do I mix resin and xylene, then add hardener? Mix resin and hardener, then add xylene? Do I need to wait a specific time before adding xylene to resin/hardener mix, or just put it all in at the same time.

Thanks,

Mark

[Laketexoma]

I have always mixed my hardner and resin together first, that way I can thin it out to where I like it.

[TRBenj]

Resin+hardener together first- you want to make sure youre properly mixed before thinning. Only thin as much as you need to get the consistency you want. It thins out pretty quick. The purpose of thinning the epoxy is to get it to soak into the substrate (usually wood) better. The solvent flashes off, eventually (the more you add, the longer it takes) so the less you can add initially, the better.

[2DLake]

Thinning epoxy resin

Thanks guys for your quick responses. I am in the process replacing the wood behind the combing pads in my 90 Ski. Do you know if the wood that the factory used was treated with anything? It looks like it may have been treated with something based on the color. Most of it still looks pretty good except for a 6" section that was completely rotted out.

[DanielC]

I am going to suggest you do not do this. That is unless you have a chemistry degree, and have specifically have studied epoxies, including the one you are planning on using.

This is my recommendation.
http://rotdoctor.com/products/cpes.html

[TRBenj]

Oh for Christs sake... its not rocket surgery. The resin is thinned with solvent, allowing it to penetrate the wood, the solvent flashes off. The wood becomes more plasticized and should be less susceptible to rot. While its certainly possible that name brand CPES will work a little better (penetrate further or flash off faster), I have a hard time stomaching a 2x cost compared to epoxy resin, when its actually diluted with a less expensive solvent.

Whats the worst thats going to happen? He's coating his combing pad backers! Sheesh.

Ive done repairs on much more critical structural components using homebrew CPES and everything has held up very well.

[Laketexoma]

Oh for Christs sake... its not rocket surgery. The resin is thinned with solvent, allowing it to penetrate the wood, the solvent flashes off. The wood becomes more plasticized and should be less susceptible to rot. While its certainly possible that name brand CPES will work a little better (penetrate further or flash off faster), I have a hard time stomaching a 2x cost compared to epoxy resin, when its actually diluted with a less expensive solvent.

Whats the worst thats going to happen? He's coating his combing pad backers! Sheesh.

Ive done repairs on much more critical structural components using homebrew CPES and everything has held up very well.

X2

[DanielC]

Everybody is entitled to their own opinion on what they want to do on their own boat.

But do you really need to use the Lord's name in vain?

[2DLake]

I am going to suggest you do not do this. That is unless you have a chemistry degree, and have specifically have studied epoxies, including the one you are planning on using.

This is my recommendation.
http://rotdoctor.com/products/cpes.html

Daniel,
My link above compares homebrew to what I believe is rot doctor. The only difference is rot doctor uses several different solvents instead of just one. The page at the link was written by resin suppliers. Surely at least one of them has some kind of degree.

I went ahead and used my homebrew and looks good so far. And, like TRB said, its only the combing pads.

Thanks for your concern,

Mark