peachfront
fully equipped rock polisher
Stones have begun to speak, because an ear is there to hear them.
Member since August 2010
Posts: 1,745
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Post by peachfront on Jul 4, 2012 7:56:18 GMT -5
Here's a quick question for you folks experienced in using epoxy. Does it have to be a heat gun, or can you use a blow dryer just as well? I assume for a small intarsia, a hair dryer would be fine. More worried about a large "pour" for a table top that I may be doing soon.
Sorry if this is a stupid question. Thanks in advance, and don't giggle too much.
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itsandbits
freely admits to licking rocks
Member since March 2012
Posts: 825
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Post by itsandbits on Jul 4, 2012 8:53:41 GMT -5
When you do an epoxy project, the formula usually just needs an average warm temperature; 70-80F to work properly; this gives it time to bond on a molecular level and the chemicals to do their job; they produce heat as part of the reaction too. A heat gun gets them up to the fire alarm temperature and for larger/ thicker projects, may actually cause cracking.
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peachfront
fully equipped rock polisher
Stones have begun to speak, because an ear is there to hear them.
Member since August 2010
Posts: 1,745
|
Post by peachfront on Jul 4, 2012 11:59:23 GMT -5
But...but...(sob) (pitiful whimper) On youtube they said that the heat gun gets the bubbles out!
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itsandbits
freely admits to licking rocks
Member since March 2012
Posts: 825
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Post by itsandbits on Jul 4, 2012 16:54:29 GMT -5
I have seen them flame the top of the surface with a quick pass to pop the bubbles but thats all, not enough to burn it though. I have heard of thinning the epoxy by heating it so you could get better crack penetration. I actually tried it on some cracked opal and used a brake bleeding vacuum pump and heated the optical epoxy in water in a small canning jar. it worked great. The epoxy was a uv activated type and I just set it in the sun and it cured.
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Post by Bluesky78987 on Jul 5, 2012 3:16:35 GMT -5
In a class on Sunday on epoxy inlay, the instructor said two sort of relevant things:
1) you can get bubbles out by passing CO2 across the surface (blowing with a straw is what she suggested - we were doing pendants). Not sure if it works, I didn't try it.
2) Heat definitely aids the setting time. She made a little oven with lightbulbs for the class - it was hot but not heatgun hot in there. So I'd say the hairdryer will probably speed things up, depending on what type of epoxy you're using.
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peachfront
fully equipped rock polisher
Stones have begun to speak, because an ear is there to hear them.
Member since August 2010
Posts: 1,745
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Post by peachfront on Jul 5, 2012 8:38:14 GMT -5
Thanks, Bluesky. One of the Youtubes I saw said the blowing on a straw method only worked for tiny projects, but I'll definitely test it on something small when I get a chance! I'm leaning toward the hair dryer at the moment...
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Post by jakesrocks on Jul 5, 2012 10:14:55 GMT -5
First step is to try very hard not to mix air bubbles into your epoxy. Stir the 2 parts gently. A few drops of acetone added to the mix will thin it some, and also give you more working time before the epoxy starts to set up.
Only 2 really sure fire ways to prevent all bubbles. The best is using a vacuum table. The other is a vibrating table. I've used both in industrial jobs, and they really do remove all of the air bubbles.
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Post by Bluesky78987 on Jul 5, 2012 10:22:48 GMT -5
Let us know how it goes!
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