Degooping hard epoxy

[sonicmojo]

Does anyone have a tip on doing this on a PCB with some epoxied components? I only need to remove about 1 inch worth. I have an adjustable heat gun but thought I would ask for tips first before attempting.

[husky]

Does anyone have a tip on doing this on a PCB with some epoxied components? I only need to remove about 1 inch worth. I have an adjustable heat gun but thought I would ask for tips first before attempting.

What amp is it?
Pretty difficult if it is potting epoxy designed for the purpose without destroying something.

[sonicmojo]

It's actually a boutique effect pedal that I've been having a lot of screeching feedback issues with and wanted to maybe add a smoothing cap to it but unless I can see what I am dealing with, it is not really possible. It's not a big loss if I kill it but I was thinking since it is PCB and not point to point wiring, it may not be possible. Maybe I can add a 1500pf cap on the level pot instead. I hate goop.

[Kagliostro]

In my knowledge no way to remove epoxy without damage something

the only way I know is by mechanical action

a little burr in a Dremel or other sistems

Kagliostro

[Phil_S]

Dremel tool, very, very carefully. If you can clamp the Dremel in place and move the board instead of the other way round, you might find control is better.

[9pins]

you could try that freeze spray stuff.

[husky]

Heat and a dental pick works sometimes but assume you might destroy it in the process, usually better achieved with a small local heat gun like an Ungar used for shrink sleeve. I would advise asking the maker though, maybe he could tell you the best way to tweak it or make you a different version. Most people are eager top please their customers. What happens if you roll down your volume on the guitar to like 8 or 9? Most guys I know when using tube screamer type pedals never put the guitar on 10 and dont use a treble bleed for that. Also try a longer cable before you hit the pedal and not ultra low capacitance.

[VacuumVoodoo]

Aqua Regis (royal water) will dissolve epoxy but unfortunately also everything that's hiding under it.

[sonicmojo]

John, thanks for the advice on the cables. I recently set up my pedalboard with some RG400 cables to the amp. I may experiment a little bit with a different return cable too. Thanks for the replies. I think I'm going to punt the idea and go back to a tubescreamer clone.

[xtian]

Aqua Regis (royal water) will dissolve epoxy but unfortunately also everything that's hiding under it.

Oh, yeah. I have some of that.

http://en.wikipedia.org/wiki/Aqua_regia

[halfbackstrat]

Epoxy resins should dissolve into Acetone?

It's an Organic Ketone and thus should be ok with the components, provided you don't get much on them.

Hope this helps.

Source: Chemistry Student

[Omicron]

Acetone works on uncured epoxy resins. I've never seen acetone do anything to cured epoxy. This is from experience w/ fiberglass boat repairs.

The only way I've ever removed cured epoxy is physically, through sanding, grinding, etc.

[PWE Amplification]

If you look at the spec sheet for some encapsulating epoxies you'll see that acetone will indeed disolve it...after 30 days of submersion

[Zippy]

If you look at the spec sheet for some encapsulating epoxies you'll see that acetone will indeed disolve it...after 30 days of submersion

... as well as the circuit board.

[FUCHSAUDIO]

I bought degooping liquid from one of the encapsulation/epoxy makers. It took about a month of soaking and dental picking to get past it. By the time i got to the parts, the values had come off and each part had to be measured. It's a tough process. You have to decide if it's worth it.