Bad Epoxy, needs to be removed, any ideas?

I mixed up some 20 minute finishing epoxy, thinned it with isopropyl rubbing alcohol as I have done before successfully, brushed it on the plane covered with 1/2 ounce cloth, now it will not dry, needs to be removed. Anyone have any ideas how to best remove the bad mix of epoxy? Thanks, John from Va.

I would try the same alcohol you used to thin it.
Are there any other substrate layers under the cloth, or just balsa?

Allan Perret

>I would try the same alcohol you used to thin it.
>Are there any other substrate layers under the cloth, or just
>balsa?
>
>Allan Perret
I layed the 1/2 ounce cloth on bare balsa, then applied the thinned epoxy, bad results. Thanks. [photo not recovered: sipcof.gif]

Have you tried using a heat gun on it. I remember a flying partner of mine that finished a little 1/2A speedster with K&B Epoxy. He forgot the hardner. He stuck in in the range oven for less than an hour and the epoxy hardened up perfect. Another trick with it being summer time and temps in the 90's is sto put it in a closed up car(vehicle) for a couple of hours. DOC Holliday

Isopropyl alcohol contains water in various percentages, 30%, 70%, etc. That is the real problem. You can use denatured alcohol with no problem. It contains no water. Wish I could help on the removal. SLEEPY

Yeah, heat should cure it right up

When I thinned the epoxy, I always use Acetone and it works great. I would try Acetone to remove it also.

Sean

I'll apologise in advance if any of this
is too simplistic.

Are you sure it hasn't set up?
Is it possible that you have a thick layer
of "Blush" floating on the surface?

Yes, try the heat gun. I prefer a
hair dryer. It only warms the epoxy
without damaging it. The sunny window
suggestion is a good bet too.

The best way to remove hard epoxy is
with a heat gun and a putty knife.

The question you might ask yourself
is why this batch didn't set up.
If the epoxy is too old it will often
misbehave. A trick for rejuvenating
old epoxy is to microwave it.
WARNING! THIS ONLY WORK SOMETIMES
AND CAN BE SMELLY!
If you decide to try the microwave
trick, test a mix before using it
on an aircraft.

Hope this helps....

[photo not recovered: 29802.jpg]

One of my movie models made from
foam, glass and epoxy.

Attachment #1, (jpg file)

Morgan. How soon before it's available as a kit? Or maybe an ARF?

Floyd

Well, I heated up the epoxy with a heat gun, I'll see if that worls. I mixed up some of the same epoxy without the alcohol, showed same tendencies, kind of rubbery.

If you look in the container the epoxy in in...is it clear? or does it have white gummy crap in it? If it has white gummy crap in it you can put the whole container in about 1" of water and bring it (the water) to a boil. Then shut it off. This will rejuvinate the epoxy. And hardner as well.
This is what I do about once a year (thats about how often I use it) and I've NEVER had a problem with the epoxy not going off.

Also one of the other posts was correct: you can remove hardened epoxy with a monocoat gun/hairdryer and exacto blade. Catch the corner and it will peel right off with continued heat. I've done it dozens of times. (yes, from crashes. RC of course) I used to slope race and that really eats up the planes fast!
Good luck, Jerry

Dino,

There is a good chance that the epoxy will eventually harden fully. Keep us informed. meanwhile Ii suggest using acetone for thinning finishing resin.

Al

Hello Dr. Spark
I delivered this
as an ARF (All Ready to Float)
or maybe that should be ARS
(Sink) since it's a sub.

[photo not recovered: 29804.jpg]


Never did get it to loop.

Cheers!

Attachment #1, (jpg file)
Attachment #2, (jpg file)

Tres Cool! What movie?

That prop looks like something we could try on a stunter. It looks like (turning CCW) it could not only bite, but grab and maim.. ;->

Very nice work, tell us the movie so we can watch for it!

[photo not recovered: 29334.gif]

"It is pretty hard to tell what does bring happiness; poverty and wealth have both failed. " -Kin Hubbard

Hey Guys, thanks for the interest in the sub.

The movie is still in Post Production
where the computer people do the CGI stuff.
At least I think it is(?).They don't tell me
anything after the images are in the can.

I'm taking a small risk for posting the
pictures without permission at this stage,
so I don't want to say too much.

If you have a taste for B movies you might
have already seen my work.

Compared to building a competitive CLPA
plane, movie work is a snap!

[photo not recovered: 29803.jpg]

Well, I heated up the bad epoxy with a monokote heat gun, it is now dry to the touch, I have not put any filler on it yet, probably use Sig Lite-Coat, we shall see! Thanks all, for the imput. John from Va.

In applying epoxy on bare balsa, you run the risk of separating the hardener from the resin. Don't ask me more details, but that is what it looks like from the outside. I have even seen this happening with polyesther resin.
Therefore, you want to put at least one coat of dope on the balsa. Also , you have to really stir the epoxy longtime, long enough for it to start reacting, before you apply it.

Now with your mishap, there is no alternative but fully remove the sticky stuff. I do this by scraping techniques, rather than looking for diluents. It is a terrible accident to happen and I commiserate with you.