Potting removal options ?

[KD0CAC John]

Got another repair issue - a potted circuit board , this one has off white color  .
But would like to hear options , maybe some types more removable , and not , ;( ?

[Haenk]

Is it silicone based, or more like rock-hard stuff?

[jonpaul]

photos?

[KD0CAC John]

Ok have a picture , it is hard - with a little flex , but can not make a mark with finger nail .

It is part of a Dewalt 60volt air compressor .

My guess is that I turned on with max pressure in tank 120lbs , maybe the high current darw of trying to start against full pressure cause a failure .

Tried another battery [ incase the BMS turned off the other battery ] still not working .

Looks like a 3 phase motor with control board [ pictured ] between motor , battery , switch & pressure switch --- I did jump the pressure switch incase it was cause " no run " .

So figured fault in potted board .

Thanks for refplies

[jpanhalt]

People who clean up fossils do that all the time -- and I mean years of picking.  Good luck.  There really is no solvent for epoxy, silicone, and numerous other polymers.  Removal requires melting, if possible, or denaturation (i.e., chemically burning it, etching), or physically picking it off.  Some solvents, e.g., methylene chloride, may make it more flexible so it comes off in larger pieces, but that is still a lot of work.  Melting is not practical for epoxy and silicone. 

[inse]

Recently I depotted a high voltage module that I destroyed by drawing arcs.
I put it into the oven at 150 degrees centigrade- the compound could easily be scraped off but it smelled nasty.
After repair I re-potted it with clear epoxy.
Give it a try, nothing to lose.

[jchw4]

I had some funny experience with that: https://www.eevblog.com/forum/reviews/ikea-ledare-teardown/msg4197535/