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vaccuum
By:tom preska
Date: 12/5/2000, 12:08 pm
In Response To: Solutions for bubbles in epoxy (Vaclav Stejskal (OneOceanKayaks))

If you mix the epoxy and get a lot of bubbles is it possible to draw the bubbles out with vaccuum? I think i saw that somewhere probably in epoxy casting literature. You would have to get a science class glass jar with an attachment for a rubber hose and hook it to your flowing sink. of course you would need the sink adapter and the (whatever you call it) jar or a vacuum pump. But you should be able to draw out the bubbles prior to application.

Tom

: The first issue is to identify what's causing the bubbles.

: 1) The most common problem is bubbles whipped into viscous epoxy (System
: Three is certainly viscous). The solution is to pre-warm both the hardener
: and resin and mix them carefully together (don't heat the epoxy after
: mixing because you are robbing yourself of precious work time (pot life)).
: The alternative is to use less viscous epoxy. The bubbles are trapped (as
: in cold honey) and may not have the time to get to the surface or pop
: before the epoxy thickens even further.

: 2) First pre-heat the wood with a hair dryer or increase the temperature in
: your shop. Turn heat down, wait 5-10 min and start applying epoxy. The
: cooling air in the wood will suck the resin into the pores rather than
: outgassing. If your shop is constant temp, this is not the cause. Also,
: this happens mostly when you seal the second side of the panel as opposed
: to the first coat on fresh unsealed plywood. The air is trapped and there
: is a higher chance for bubble formation.

: 3) Do yourself a favor and get rid off all the 'brushes' especially the foam
: types. Foam rollers and brushes are GUARANTEED to introduce froth into
: epoxy as you apply it over 'hairy and rough' wood grain. Use only plastic
: squeegee!

: 4) John has a good idea with the alcohol sprayed on the surface. Both alcohol
: and carbon dioxide (in a torch) reduce the surface tension of the epoxy
: allowing the small bubbles to escape. Heating the epoxy after application
: is however going to cause outgassing.

: My suspicion (without knowing more details) is that your shop may be a bit
: too cold and the epoxy too viscous.

: Vaclav

Messages In This Thread

HELP: Bubbles in epoxy
Severne Johnson -- 12/1/2000, 11:30 am
Solutions for bubbles in epoxy
Vaclav Stejskal (OneOceanKayaks) -- 12/3/2000, 10:46 am
vaccuum
tom preska -- 12/5/2000, 12:08 pm
vaccuum epoxy bubbles
Vaclav Stejskal (One Ocean Kayaks) -- 12/5/2000, 5:30 pm
Re: Imploding Marshmellows & Thanks . . .
Spidey -- 12/7/2000, 7:35 pm
Re: Imploding Marshmellows & Thanks . . .
Vaclav -- 12/7/2000, 7:59 pm
Re: HELP: Bubbles in epoxy
Lee -- 12/1/2000, 5:40 pm
Re: HELP: Bubbles in epoxy
Severne Johnson -- 12/1/2000, 5:55 pm
Re: HELP: Bubbles in epoxy
John Monfoe -- 12/2/2000, 4:40 am
Shop temperature and alcohol
Severne Johnson -- 12/4/2000, 11:29 am
Re: Shop temperature and alcohol
John Monfoe -- 12/5/2000, 5:34 am
Re: Shop temperature and alcohol
Severne Johnson -- 12/14/2000, 5:58 pm
Re: Shop temperature and alcohol
John Monfoe -- 12/15/2000, 4:37 am
drink more -- shop feels warmer! :) *NM*
Dean Trexel -- 12/5/2000, 6:16 pm
Re: HELP: Bubbles in epoxy
Jason Given -- 12/1/2000, 12:19 pm
Bubbles in epoxy
Jason A. -- 12/1/2000, 12:09 pm