Dissolving epoxy/Flash circuit electrodes problem(s)

saefroch · Mon Jun 20, 2011 6:34 pm

Is there anything that I can use to dissolve epoxy? I just accidentally epoxied my electrodes together...

clemsonguy1125 · Mon Jun 20, 2011 6:41 pm

Heres some ideas.
http://www.smokstak.com/forum/showthread.php?t=22619

ramses · Mon Jun 20, 2011 6:41 pm

fire/heat (outside or in a real fume hood only).

Beyond that, it depends on the specific epoxy

al-xg · Mon Jun 20, 2011 6:47 pm

Methylated spirits, works well before it dries...

A few companies specialise in "dissolving" and recycling thermosetting composites, but it still isn''t really practical and very polluting.

After a quick search, apparently dimethylformamide or high concentration sulfuric acid will work... sort of risky stuff.

saefroch · Mon Jun 20, 2011 6:49 pm

Yeah, I found the same thing. A bunch of solvents I don't have and don't see any way to get quickly. I'll try the heat.

Mon Jun 20, 2011 6:54 pm

How strong are your electrodes? I've always found a chisel and hammer gets rid off the main type of epoxies that dry hard like Araldite or JB-Weld.

Fnord · Mon Jun 20, 2011 6:54 pm

About 50 amps at 20Kv through the electrodes should dissolve the epoxy just fine.

ramses · Mon Jun 20, 2011 7:13 pm

Fnord wrote:About 50 amps at 20Kv through the electrodes should dissolve the epoxy just fine.

are you suggesting that he connect one to ground, and throw a lead connected to the other over a relatively high tension powerline? Because I can't think of anywhere else to get 1 MW.

Would 20kv even cause dielectric breakdown in the epoxy?

Zeus · Mon Jun 20, 2011 7:13 pm

I've heard that nitric acid does a good job, I was reading about people using it to get access to the insides of ICs.

Such is the wonders of being bored in an area where internet filters are set on Cult level.

Edit: I daresay Fnord was having a joke, it would work, but it's quite impractical. Not to mention a little dangerous.

Theres a high likelyhood of gibbing also.

saefroch · Mon Jun 20, 2011 9:16 pm

MrCrowley wrote:How strong are your electrodes? I've always found a chisel and hammer gets rid off the main type of epoxies that dry hard like Araldite or JB-Weld.

Sadly that's not really an option, since they're tiny, and because of what they're encased in, which I'd REALLY like to keep:

I fashioned the electrodes crudely out of the electrodes from an old spark plug, and they're housed inside a flash tube that I ground down and put a hole in. The epoxy ran inside the housing too far while it was curing, and I highly doubt the current will arc through the air with the epoxy connecting the electrodes.

ramses · Mon Jun 20, 2011 9:59 pm

epoxy is an insulator, so you might be able to get some kind of arc. If there's too much current, you are more likely to break the tube, since there is less volume for the air to expand into.

if the arc is sufficiently hot, the epoxy will begin to carbonize, and later short out the electrodes.

If heat doesn't work, this is starting to look like a total loss. You might be able to salvage the electrodes, but the tube may be doomed.

saefroch · Mon Jun 20, 2011 10:01 pm

ramses wrote:the tube may be doomed.

Ah well... This one was rather better than the first one I made, which met with the same results.

saefroch · Mon Jun 20, 2011 10:30 pm

Well I'm double posting because I changed the title of the thread to reflect it's now-changed nature. I connected a simple pizeo to both electrodes and it appears that there is arcing occurring at the connection of the electrodes to the wires coming off the piezo, but not in the spark gap (which is immersed in epoxy)... any ideas on what's conducting? The epoxy?

Video added:
[youtube][/youtube]
Upon closer examination it appears that it is arcing through the glass... What?