Need a consensus

[Oldcoot2]

I have been using just a bit of acetone to thin my epoxy down just a touch in order to apply a thin layer for joining various planks.
Recently, my epoxy started the "Never Cure" bit. I have tried different epoxies and still wind up with the same results.
Any new suggestions out there? :confused:
Gerald

[schrederman]

Gerald,

Try using 99% isopropyl alcohol instead of acetone. Lots of epoxies have gone away from being solvent based. Make sure you get the 99% instead of the 90%. You may have to ask the pharmasist.

Jack

[jtlsf5]

Your problem may be in the way you are mixing rather than the mix itself. Acetone should little affect on the cure, especially if you only use a little. I routinely use isopropyl alcohol (as JW mentions), and have used acetone successfully in the past.

Two key points if you use this method:

1. Blend the epoxy in the proper proportions first, and thoroughly mix it before adding the thinning solvent. You need to establish the chemical reaction that will cause it to cure before you thin it. To do otherwise could very well cause your "nevercure" problem if the solvent dissolves either or both of the components before they can react. The process of solvation involves molecules of the solvent surrounding and lightly bonding to the dissolved substance. This in effect prevents the components of the epoxy mix from adequately getting to each other.

2. After you apply your thin layer, allow it to stand for a few minutes (assuming you are not using 5 minute epoxy) to allow most of the solvent to evaporate or absorb into the wood. Then press the pieces together.

JT (the chemist)

[schrederman]

What JT said... ;)

[crashagain]

A little trick I have used is to use your little heat gun and heat up the e-poxy a little. It will thin it out quite a bit.
Be sure you use a slower setting epoxy not the 5 minute stuff, the heat will speed up the curing process...

[lincoln]

Some kinds of epoxy are quite thin and easy to spread. Try one of those. (I'm not remember which popular brands, though.)

[prodjx]

MGS is the thinest I've ever used and the best, when using a credit card to apply I use an ounce to do both the upper and lower skin's, 1/32in balsa, on a 30 inch panel. Dave.

[Oldcoot2]

Great help! I knew it was out there. I think I will try Vader's idea of the 99% alcohol after letting the epoxy work a bit after mixing.
By the way, Jack.....any word on your employment opportunities?

Thanks to all
Gerald

[Daryl Perkins]

Oldcoot,

Why are you thinning epoxy anyway? I try to pick a material that has the properties I am looking for for a particular purpose. If your epoxy isn't thin enough, I'd select another resin.

For laminating - West, Pro-set, MGS... etc... no need to thin any of these if you apply them properly.

My old flight instructor used to tell me by operating my aircraft outside the manufacturer's placards and published flight limitations, I'm now a test pilot. You start thinning resin, you're now a test pilot. ;) Who knows if it'll cure or not. That's not worth my time, or a ruined part.

JT and Jack know what they're doing. Good advice, but I would keep it simple.

Good luck with your project

dp

[Oldcoot2]

Daryl
Thank you for your response. My building plans from Ray Hayes say to use thin 30 minute epoxy for joining the fuselage sides. I have two brands of epoxy and they are both pretty thick. My epoxies last so long that I have to throw them out over time. MGS is a new one to me, and when I have to replace again I will certainly keep it in mind.
Anyway, being frugal I am thinning the epoxy. I have taken the advice of Jack and JT, and it works. My overnight test proved positive in that the epoxy blob I made up was harder than the hubs of hell this morning.
Thank you for your advice and help. :p
Gerald

[jtlsf5]

Anyway, being frugal I am thinning the epoxy. I have taken the advice of Jack and JT, and it works. My overnight test proved positive in that the epoxy blob I made up was harder than the hubs of hell this morning.
Thank you for your advice and help. :p
Gerald

Gerald,
Did you try both acetone and isopropyl alcohol in separate tests, or just isopropyl?

JT

[prodjx]

Daryl, your absolutely right. I've gone beyond my mgs's use date and it still work's for me, though I think I should probably use it up on several molds I have.
Also the chemist's have put alot of time creating these great epoxies I think they know more about formulation's than we do. Dave

[Oldcoot2]

JT
Tried them both. The acetone still failed, but the isopropyl worked like a champ. This was after mixing two small batches of 30 minute epoxy, waiting about 2 minutes for the chemical reactions to take place then adding small amounts of acetone, and isopropyl to the mixes.

I think I will rob the kitty and go buy a batch of MGS for the rest of my build.
Sure don't want to take any further chances on this Oly III.
Thanks,
Gerald