Best alcohol for thinning epoxy?

I need to slightly thin some 30 minute epoxy to make glassing a wing center
section easier. I know that the high water content of isopropyl tends to
weaken the epoxy, so which would be best? Denatured ( ethyl with methanol
added ) or straight methanol?
Thanks,
Mark D. Fain
Reply to
Mark D. Fain
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On Tue, 28 Jun 2005 10:16:49 -0400, "Mark D. Fain" wrote in :
If you're just fuelproofing or otherwise "painting" the epoxy on, I'll bet you couldn't tell the difference between these two.
I'd use whatever you have most of on your shelf.
If you're trying to get epoxy to flow a bit and want to retain much of its strength, you can heat it. It doesn't take much. It will flow like water, then set up very, very quickly. Check for drips and clean them up quickly--you've only got a small window of opportunity to do so.
Marty
Reply to
Martin X. Moleski, SJ
I don't use alcohol at all, spread the stuff on, use a heat gun to GENTLY warm the epoxy up a LITTLE, and it will flow and soak through the fiberglass into the wood VERY well use one of those fake credit cards you keep getting in the mail as a squeegee to force the epoxy through the cloth and to get any air bubbles out, once you can clearly see the wood grain through the fiberglass, the glass is fully saturated, and the epoxy is down to the wood. then use a roll of TP or paper towels to mop off the excess epoxy
you may want to go back later and fill the mesh with something later, but leaving gobs of excess epoxy on the surface adds a LOT of weight and contributes very little if anything to the strength.
this method works for me, YMMV bob
Reply to
Bob Cowell
You may want to hunt around for some epoxy resin that's meant for layup. Glues are intentionally thickened; a resin will be formulated to do exactly what you want.
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Reply to
Tim Wescott
Bob & group -
Please excuse a newbie question, but I have seen this before and not understood it very well. Do you mean using the whole roll of TP/towels like a paint roller? Is there some way to use the absorbent without it sticking to the epoxy & mixing with it? Is this done in addition to the credit card squeegee?
Tnx - LeeH
Reply to
LeeH
Don't add alcohol to epoxy. It screws it up. I mean, you use epoxy because it is supposed to be strong. If you don't care how strong it is, use water based polyurethane paint. It works well as a fiberglass binder too.
But, as Marty suggested, to thin epoxy, the best thing to do is to use a slow curing epoxy and then heat up both tubes in warm tap water. That will thin it to good brushing consistency and will not significantly weaken its strength. It does speed up the curing time, so keep an eye on it.
Ed Cregger
Reply to
Ed Cregger
That is exactly what I do, use it like a paint roller. move pretty fast, and keep stripping off the outside layer.
It doesn't take NEARLY as much paper as you would think, particularly if you use a "credit card" or old playing card or something to squeegee off most the excess before you mop up the drips.
the epoxy will tend to act almost like heavy oil or thin grease, and the TP or paper towel will pretty much skate over the top without sticking PROVIDED that you work fairly quickly, and don't let the epoxy get tacky before you start cleaning up.
bob
Reply to
Bob Cowell
I don't remember who first posted this method, Might have been Lyman Slack, or one of the other "senior" members of the group.
Reply to
Bob Cowell
Another good thing to do is to heat the parts to be glued with the old heat gun, rather than the epoxy itself- this does not shorten the pot life of the mixed epoxy, and really makes it flow into every crack and soak into the wood as soon as you apply it. - I'm here to help - Paul
Reply to
Paul Ryan
Go to the drug store and get some 99% alcohol. Last I bought was about $3 per pint. I have been using this for years with no problems. I also thin Epoxy finishing resin with it for glassing / reinforcing Quickie 500 pylon racer wings .Powered with Nelson engines they go over 150 mph. Holds okay on these.
Ken Day
Reply to
Ken Day
Laquer thinner works well. Some contain a small amount of alcohol, but not enough to attract much water. But this will weaken the epoxy. I only use it for fuel proofing.
Reply to
Sport Pilot
Lyman, WHERE do you find Epoxy thinner? I've never seen anything labeled as such. I use alcohol which is listed as the thinner in a lot of places. It works great.
Reply to
Jim Slaughter
The drugstore variety has water in it. Go to a hardware store and buy a GALLON of denatured alcohol for $8. Better stuff, same price.
Reply to
Jim Slaughter
On Fri, 01 Jul 2005 17:39:14 GMT, "Jim Slaughter" wrote in :
I thought Lyman might be making a joke.
One quick peek at google showed me I was wrong.
Marty
Reply to
Martin X. Moleski, SJ
On Fri, 01 Jul 2005 20:54:45 GMT, "Jim Slaughter" wrote in :
I presume that if you're intent on thinning epoxy, it's going to turn out to be used for a paint-like purpose.
I doubt that any of the commercial expoxy solvents would be any worse than the home brews we've been recommending. :o)
Marty
Reply to
Martin X. Moleski, SJ

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