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jtrieck
01-16-2009, 07:39 PM
Anyone built a boat the way he does, heating the shop up real high and then turning on the A/C while he slathers on the epoxy?

Seems miserable, but maybe its not as bad as I am imagining. Why wouldn't some of the epoxy sealers do nearly as good a job?

SMARTINSEN
01-16-2009, 08:11 PM
Right now around here it is about -10 F. I would be hard pressed to get my shop up to 40F, never mind 140.

Pleasant thought though.

James McMullen
01-16-2009, 08:53 PM
Some of us prefer not to have so much exposure to epoxy if we can help it. . .plus my shop is not in Florida.

Working in that heat seems beyond miserable. I do miss Robb White, though. I'd reccommend his book to anybody. Hilarious!

ccx2
01-16-2009, 08:56 PM
I googled it and couldnt find anything , what the heck are ya talkin about.

Brian Palmer
01-16-2009, 09:38 PM
Heat the shop (or really just the parts) before applying epoxy. Apply epoxy. Then cool shop, and cooling air contracts and pulls epoxy deeper into joints.

In reality, I do not think you could get enough of a temperature difference to make that much difference in the volume of air involved. You are not going to simulate a vacuum bag or autoclave situation.

What he probably did was just reduce the viscosity enough so that the epoxy flowed more easily.

Brian

SMARTINSEN
01-16-2009, 09:56 PM
What he probably did was just reduce the viscosity enough so that the epoxy flowed more easily.

Brian

And then, as the expanded cells of the wood cooled from the outside in, the epoxy is driven deeper into the wood, if I understand the method correctly.

StevenBauer
01-16-2009, 10:10 PM
He wasn't trying to get the epoxy deeper into the wood, just deeper into the joints. He didn't like messing with epoxy either. that's why he put all the epoxy on at the end, instead of gluing each lap as he went along.


Steven

RFNK
01-16-2009, 10:53 PM
When sheathing our plywood Folkboat deck with epoxy and glass, we glassed in the afternoon when the deck is cooling. This is to prevent air expanding under the glass and for the cooling plywood to suck epoxy in. This is in Australia, in summer, where the temperature during the day would typically range from around 20 - 30 degrees C but, in the sun, can go to around 40 degrees at midday. Rick

JimD
01-16-2009, 11:08 PM
...This is to prevent air expanding under the glass ...

Yup. The gas trapped in the wood expands and escapes out of the wood as it pre heats, so no outgassing into your nice epoxy/glass work. If you can't heat up your shop then just leave the wood to be epoxied out in the sun for a while. I do this every time in the summer.

P.L.Lenihan
01-17-2009, 02:46 AM
His method is correct and does not really need a huge temperature differential....although where he lived he did have to get it hotter then it already was :)
Otherwise, intead of a wonderfully smooth, slick,epoxy surface you risk ending up with a gadzillion little epoxy bubbles peppering the surface which then have to be sanded off......absolutley no fun!

Don't ask me how I know this..........


Peter

PeterSibley
01-17-2009, 05:36 AM
His method is correct and does not really need a huge temperature differential....although where he lived he did have to get it hotter then it already was :)
Otherwise, intead of a wonderfully smooth, slick,epoxy surface you risk ending up with a gadzillion little epoxy bubbles peppering the surface which then have to be sanded off......absolutley no fun!

Don't ask me how I know this..........


Peter

I used to use a lot of a finishing epoxy marketed as Photogloss .You apply a very thick layer and it forms a dead smooth high gloss finish ....it also gets millions of small air bubbles in it if you haven't sealed the surface .Sometimes I sealed but found it easier to run a propane torch over the job .The epoxy softens ,even after it has started to set up and the bubble burst and disappear .It works well and if you use a particular brand all the time it might be worth playing with .

Saltiguy
01-17-2009, 01:59 PM
I was a big fan of Rob White, but some of his epoxy/fiberglass techniques seemed eccentric and troublesome to me. It's always a good idea to do epoxy coating on a dropping temperature. That's basic, for all the reasons mentioned, and it's always wise to have dry wood - the dryer the better, to soak in the epoxy. Having said that, I don't think it necessary to heat up the work area to extremes. When coating, or laying glass, I pre-coat with epoxy that I've thinned about 10% with lacquer thinner. On dry wood, it gets sucked in as fast as you can broadcast it onto the wood and being extremely thin, you know it is getting into all the little fissures (especially in fir). Then, when the solvent has evaporated, and the epoxy is green, I do my next coat with or without glass as the case may be. This works great and has proven itself over 25 years.
Rob also talked about how he would glass his craft with little scrap pieces of cloth - sit there with a brush and dab, dab, dab - one little piece at a time. Not for me. No thank you. I prefer the biggest cloth I can handle and to apply my epoxy with a squeege. If you precoated as I do, the cloth will wet-out real quick and you'll have a perfect job with little fuss.

ABfish
01-17-2009, 09:12 PM
I recently downloaded a copy of West Systems epoxy manual from the internet. There is a section of the manual that discusses pre-heating a lamination before epoxy application to increase penetration....the first thing I thought of was Mr. White's method of pre-heating his entire shop.