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Re: Solving solvent worries
By:Joe
Date: 1/31/2002, 1:12 am
In Response To: Solving solvent worries (Paul G. Jacobson)

Just want to say that just because I am serious about getting an answer to this (and have never liked easy answers,ones that are too "easy" for their own good anyway) does not mean I am trying to make Dr. Rot or anyone look bad. Don and Paul "get" where I am comming from, it is only to understand what is happening and not wanting to just take the first thing any "expert" may say as gospel if I have a question or something doesn't add up. It isn't personal... It more important than that it for the BOAT !!! I want to do the CPES but I AM NOT LOOKING TO BUY SOME NEW TROUBLE with CPES (or anyone on this board). That's all.

Paul I notice we have one of the very same concerns although I did NOT post this part in my earlier messages. But I did tell Dr. Rot: My hull and deck have already been sealed and glassed with "Clear Coat" and fill coats of regular epoxy over that. So the CPES will seal the hull and epoxy over that will seal in the CPES, just like you wrote this is a cause of concern and that is the situation I am talking about. I too would be much less concerned if the "other side" were not already sealed.

Like you said:

"Then again, it might not matter too much. You'll be applying the cpes and the finish coat on one side of the wood at a time. Even if you only wait a couple of hours before putting on your final coat of epoxy, the back of the wood is still open enough for those solvents to evaporate through that side when the front is
completely sealed.

What you wrote without even know that that was my situation was right on!:

"What I don't like is the possibility that some solvents would be trapped in the wood and CPES when you are applying the "final" coats of epoxy resin.

"Polyester resins are thined with solvents which evaporate as the resin cures. The evaporating solvents create their own paths out of the resin, with the bubbles of gaseous solvents forming microscopic tubes or "wormholes" through the resin. After the solvents are long gone those microscopic holes remain.
While they are far too small for water molecules to pass through, they can act a bit like Gore-Tex (R) and let the smaller molecules of watervapor through. It is a very slow process, but moisture that gets under the resin can eventually feed mold or rot spores, With drops in temperature it can condense back to liquid water, and if the boat is later left in the sun that moisture can turn to steam, which, when trapped under the resin causes it to delaminate. The saturation of the wood with epoxy or CPES is going to deter rot, and probably not allow a lot of moisture in through the solvent holes -- if indeed any gets in at all. Ideally the solvent will be totally evaporated before the resin gels, allowing the weight of the resin to sag a microscopic fraction of an inch, and pinch closed any tubes or "worm holes" that may have been formed."

Like I said all you wrote was right on, BUT without more understanding (like these questions) I have already realized that I am stuck with only the uninformed choice of what you also said: "You either wait two days before coating the stuff, or you wait 2 hours." This is ok if there can be no better knowledge. I would just let the whole CPES seal coat evaporate and set up for days, but Dr. Rot says his chemists say the bond is much better if the next coat is applied while the seal coat is "tacky". Anyway to those who think this is a fair question to look for an answer here on this board of boat builders, I'd really like to hear the why's or way's of thinking about this. If some think what's the big deal, or just ask HIM about it, I only wonder if that couldn't be just as true of 90% of the questions posted and asked on this board. I mean how many times is "How long before my epoxy gets a blush and I have to sand before recoat asked here?" Can't System 3 or MAS answer that (They DO right in the book they GIVE you when you buy the stuff), but questions like that get posted here day after day, so can't see why "Go ask somewhere else" applies to this question. I know I can ask Dr. Rot, he seems like a great guy, so that is no problem. BUT I have found this board powerful for how much people KNOW and CARE. So I am CHOOSING to try to educucate myself before I just go back again for the third time (with the same questions) but not one bit more to knowledge to help me find out all the facts from him. Anyway I think it is a fair question for this board and I have already learned from Paul's points that the concern I have of sealing over CPES too soon is real. Thanks to all for their time, experience and input. As a novice I try to do the same if I think my "knowledge" will do no harm, but if I don't have a good idea of the issues involved in a question I don't just pull something out of the air, or say why not ask somewhere else.

Joe

Messages In This Thread

Epoxy: To Evaporate and Blush or not to .....
Joe -- 1/30/2002, 8:20 pm
Re: Epoxy: To Evaporate and Blush or not to .....
Steve Smith -- 2/1/2002, 4:38 pm
Thank you Mr. Smith
Pete Rudie -- 2/1/2002, 5:52 pm
Re: Epoxy: To Evaporate and Blush or not to .....
Jim Chowning -- 2/1/2002, 10:40 am
Thanks for the answer
Pete Rudie -- 2/1/2002, 12:09 pm
Re: Thanks for the answer
Jim Chowning/The Rot doctor -- 2/1/2002, 12:55 pm
Re: Thanks for the answer
LeeG -- 2/1/2002, 1:41 pm
Re: Thanks for the answer
Jim Chowning/The Rot doctor -- 2/2/2002, 12:31 pm
Re: Thanks for the answer *Pic*
Pete Rudie -- 2/2/2002, 1:46 pm
Re: Epoxy: To Evaporate and Blush or not to .....
Severne -- 1/31/2002, 11:52 am
Just when things looked clear...
Pete Rudie -- 1/31/2002, 9:31 pm
Re: Just when things looked clear...
Joe -- 2/1/2002, 3:01 am
Re: you are a reasonable guy
LeeG -- 1/31/2002, 10:52 pm
Only 1/32" Penetration ???.....
Joe -- 1/31/2002, 2:40 pm
Re: Greater Penetration
Chip Sandresky -- 2/1/2002, 12:45 pm
Re: Only 1/32" Penetration ???.....
Pete Rudie -- 1/31/2002, 2:56 pm
Re: Only 1/32" Penetration ???.....
Nick Schade - Guillemot Kayaks -- 2/1/2002, 10:54 am
Good point. And it IS Softwood. *NM*
Joe -- 2/1/2002, 11:11 am
however
mike allen ---> -- 1/31/2002, 3:05 pm
Re: however
Jim Chowning/The Rot doctor -- 2/1/2002, 7:36 pm
Re: however
Pete Rudie -- 1/31/2002, 6:22 pm
Re: however
mike allen ---> -- 1/31/2002, 6:38 pm
I asked Dr.Rot to come and answer us HERE!
Joe -- 1/31/2002, 4:45 pm
Re: I asked Dr.Rot to come and answer us HERE!
Nick Schade - Guillemot Kayaks -- 2/1/2002, 10:49 am
Re: Only 1/32" Penetration ???.....
LeeG -- 1/31/2002, 3:01 pm
It's not really blush .....
Pete Rudie -- 1/31/2002, 1:40 am
But could it be . . .
Paul G. Jacobson -- 1/31/2002, 10:33 pm
Good point,
Pete Rudie -- 1/31/2002, 11:50 pm
MORE than fair. Thanks *NM*
Joe -- 1/31/2002, 7:31 pm
Re: It's not really blush .....
Joe -- 1/31/2002, 3:04 am
Re: It's not really blush .....
LeeG -- 1/31/2002, 3:27 am
Re: Pure Speculation...
Nick Schade - Guillemot Kayaks -- 1/31/2002, 9:02 am
Re: Pure Speculation...
Tom Johansen -- 1/31/2002, 5:53 pm
Re: Pure Speculation...
LeeG -- 1/31/2002, 8:31 pm
Re: Pure Speculation...
Jim Chowning/The Rot doctor -- 2/1/2002, 2:01 pm
Re: Pure Speculation...
LeeG -- 2/1/2002, 5:17 pm
No speculation here...
Pete Rudie -- 1/31/2002, 6:15 pm
Dr. Rot replies ....
Joe -- 1/31/2002, 7:01 pm
Re: immaculate speculation
LeeG -- 1/31/2002, 2:56 pm
Limitations
Pete Rudie -- 1/31/2002, 11:21 am
Re: Limitations
Jim Chowning/The Rot doctor -- 2/1/2002, 1:49 pm
Re: Limitations
Nick Schade - Guillemot Kayaks -- 1/31/2002, 12:59 pm
Re: More Speculation...
Shawn Baker -- 1/31/2002, 10:46 am
Solving solvent worries
Paul G. Jacobson -- 1/30/2002, 10:50 pm
Re: Solving solvent worries
Joe -- 1/31/2002, 1:12 am
Re: Solving solvent worries
Jim Chowning/The Rot doctor -- 2/1/2002, 1:16 pm
Re: Epoxy: To Evaporate and Blush or not to .....
LeeG -- 1/30/2002, 8:54 pm
Re: Epoxy: To Evaporate and Blush or not to .....
Joe -- 1/30/2002, 10:13 pm
Re: Epoxy: To Evaporate and Blush or not to .....
LeeG -- 1/30/2002, 11:17 pm
Re: Epoxy: Good questions
don -- 1/30/2002, 10:48 pm
Re: Epoxy: To Evaporate and Blush or not to .....
Jon Murray -- 1/30/2002, 10:35 pm