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thinning epoxy

Old 10-19-2006, 07:01 PM
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wildhair
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Default thinning epoxy

Could anybody tell me what the best way to thin 30min epoxy? Thanks
wildhair
Old 10-19-2006, 08:26 PM
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rajul
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Default RE: thinning epoxy

Hi wildhare, adding a few drops of methanol will thin it down, but the epoxy will take a much longer time to cure (much longer than 30 mins) and it will turn out to be a little rubbery. I would recommend you to use finishing epoxy, which is low in viscosity, easy to work with, and cures hard.
Old 10-19-2006, 08:31 PM
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Default RE: thinning epoxy

Here's a link to Z-poxy that might help http://www2.towerhobbies.com/cgi-bin...&I=LXCX58&P=ML
Old 10-19-2006, 08:45 PM
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Default RE: thinning epoxy

Thanks Mark for the info I'll order some now.
wildhair
Old 10-19-2006, 09:05 PM
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Default RE: thinning epoxy

You're most welcomed!
Old 10-19-2006, 09:35 PM
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Default RE: thinning epoxy

I wouldn't use methanol, even if I had some pure methanol instead of 'normal' fuel that contains nitro, oil, etc. Isopropyl alcohol works fine and 91% is better to use than 70%; both are available at drugstores. You can also use denatured alcohol, but I've never seen a benefit over IPA and the IPA is normally in your home anyway. Just use only small amounts to get to your desired viscosity.
Old 10-19-2006, 10:08 PM
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Default RE: thinning epoxy

Just say no to thinning epoxy.

Warm the stuff up to make it flow. If you are doing a glass tape wrap of a dihedral break, use a heat gun to heat the epoxy and a credit card to work it into the cloth. If you are glassing a wing, fuselage, etc., then use a finishing resin (or laminating resin) as has been suggested.
Old 10-20-2006, 07:25 AM
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Default RE: thinning epoxy

Just say no to thinning epoxy.
While I agree with the above sentiment for the applications mentioned, thinning epoxy is very appropriate for areas that aren't using the epoxy for strength, but where it is being used for fuel proofing and waterproofing, such as firewalls, fuel tank areas and the fuselages, hulls, floats, etc. of float planes. Thinned epoxy is very good for these areas and adds less weight than the heated epoxy method.
Old 10-20-2006, 08:53 AM
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Default RE: thinning epoxy

I've had good results with denatured alcohol. It's readily available at your local hardware store.

Scott
Old 10-20-2006, 03:09 PM
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Default RE: thinning epoxy

(covers ears) lalalala

Yes, of course you can thin epoxy with alcohol (or acetone, MEK, etc.) Yes, the results can be quite satisfactory. It's just less than optimum and it's generally not necessary. There are products made especially for each of these applications if warming the epoxy doesn't cut it for you.

If all you want to do is fuel/waterproof, then epoxy paint comes to mind. You will generally want to seal the surface, so then sanding sealer and lacquer or dope start to sound good. Whatever floats your boat, man.
Old 12-07-2006, 09:58 PM
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Default RE: thinning epoxy

Thinning epoxy I don't. westsystems.com has detailed methods to thin without adding anything. Acetone is what I would use if anything for non structual repairs but never for building a plane. They use it for rotted wood repairs in boats where water has turned the wood under glass to black mush.
Thinning polyester resin is the norm and I had to fight the urge when using zpoxy the first time and now West systems 105/205. Working it in with a squeege or brush and let it gell before trimming the excess.
Old 12-08-2006, 11:21 AM
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Default RE: thinning epoxy

Hi charlieoneseven,

could you enlarge on the details from westsystems.com. Were is the info located?

Regards.

Karl.
Old 12-08-2006, 01:14 PM
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Default RE: thinning epoxy

http://www.westsystem.com/ewmag/14/ThinningEpoxy.html

Tom
Old 12-10-2006, 11:57 PM
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Basil Yousif
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Default RE: thinning epoxy

Rubbing alchahol works good with 30 minute epoxy to make a small amount of coating for the Hull of your model.
I had 6 planes to finish so I went and got the Marine grade Epoxy and hardner from Tap Plastics with some fiberglass netting for around the
firewall. That stuff is excellent. You can mix it with a small paint brush and coat the inside of the model fast and get a
super coat thats many times stronger than the 30 minute epoxy with rubbing alchahol mix. It mixes to a perfect consistancy for spreading out and
and doesn't smell bad like 30 minute. You can also fabricate or repair a fiberglass cowell or fuse with the fiberglass netting and the resin mix.
For $35 you can get alot of this Epoxy and hardner combo. I've coated three models and havn't made a dent in the can yet.
I won't ever use the 30 minute rubbing alchahol mix again its inferior to Marine grade Epoxy.
Old 02-07-2007, 12:57 PM
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RES Flyer
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Default RE: thinning epoxy

I have also used the West "penetrating" epoxy (to actually repair a full-scale rotten boat hull). Its a great product. I have started using other West epoxies in place of the 30 minute stuff because it is much easier to work with.
Old 02-07-2007, 05:16 PM
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Basil Yousif
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Default RE: thinning epoxy

The Marine grade epoxies are much higher grade than the 30 minute epoxy for coating and fiberglass fabrication. I just picked up more planes at a close out sale and my epoxy mix will take care of those and the other planes I have waiting to be built. If you didn't know about the marine grade epoxy you would probably spend alot of cash on 30 minute epoxy and get a infearior coat job. I want to get into making parts like a warbird fuse or cowell. A sailplane body would be nice too.
Old 02-07-2007, 07:00 PM
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Darrell B.
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Default RE: thinning epoxy

Are there any good on line sources for the marine grade epoxy? Is the hardner mixed in equal parts, or is it in a smaller volume like with fiberglass hardners?
Thanks,
Darrell
Old 02-07-2007, 10:36 PM
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Default RE: thinning epoxy

Tap Plastics sells the one I purchased. The hardner comes in three speeds. fast mediam and slow. I use mediam. Gives me a half an hour to use up about half an ounce to an ounce of the mixture before it hardens. It's around $25 for the epoxy and $6 for the hardner this makes over a quort of mixture. The Larger quort can is the Epoxy and the Hardner is the smaller can. You mix 4 parts of the Epoxy with 1 part harder. Make sure you get some fiberglass cloth for around the firewall and for retract models around the wing area. For the Hanger 9 P51 I pulled out the retract wells and put in the fiberglass and Epoxy mix to reinforce the wings.
Old 02-08-2007, 07:51 AM
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Darrell B.
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Default RE: thinning epoxy

Great looking stuff. Thanks for the info.

Darrell in Rogers

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