Disolving epoxy compound.

[Sceadwian]

Does anyone know of a way to disolve common epoxy potting compounds? I have a magnet assembly from a laser scanner that I'm trying to get the magnetic ring out of. I have access to concetrated Hydrochloric at work and that's the only thing I can think of trying. We have very pure Sulfuric and Nitric as well but I'm betting those are going to do any favors to the magnet.

Can anyone suggest anything?

 

[gerty]

I've had some luck with a heat gun, the epoxy softens enough to pull apart..

 

[jpanhalt]

I agree on the heat part. It is probably the best and most likely method to work. The glass transition temp is probably in the 130°C ball park.

If that fails, long time soaking in a paint remover for epoxy paints may soften the epoxy enough to allow you to chip it out. You will probably have to repeat that treatment many times. Let it dry between treatments, scrape, then repeat. It is a messy process. I don't know of anything that will dissolve epoxy like lacquer thinner does to lacquer.

Any even more messy process would be to use the nitric acid. Iron is reasonably stable to pure nitric acid (i.e., in the absence of water), but the amines and amides in most epoxies are destroyed. I have used nitric acid a lot in my life for other purposes, so let me emphasize that I would not even try that approach here, unless I was truly desperate for the part.

BTW, neat nitric acid is a great way to remove galvanize coatings in a controlled manner from small steel parts prior to soldering -- like the ends of pushrods used in models.

John

 

[Sceadwian]

Thanks for the tips. The heat method proved workable, I was very gentle in removing it but the magnet still cracked into about 6 pieces, I may still be able to work with it but I was going to attach it to a gyroscope to drive it externally and I don't think gluing it back together is going to do much for balancing. My heat gun did soften the epoxy but only to a hot glue like state. I think the main problem was the magnet material didn't like the heat much, it's pretty thin to begin with and the thermal expansion with the shielding material probably didn't help much. If I get another one I'll try Nitric, we have very concentrated Nitric at work and I know how to handle it safely. I'd use Muriatic to remove galvanized coatings any day, it's a lot safer to work with and safer on more substrates, especially when dilute. Our primary Zinc (galvanize) stripping method is low concentration muriatic.

 

[rickb]

dissolving epoxy

Paste type paint remover will disolve most epoxy and potting compounds. Also enamel insulation and many plastics. It is VERY alkaline and burns skin. Use gloves and don't breathe the stuff.

Rick

p.s. rare earth magnets will lose a lot of their strength if exposed to a heat gun.If it's too warm to touch, it's toast.