The Talking Machine Forum — For All Antique Phonographs & Recordings

I have an older switch that has been mummified in some manner and then stopped working. My question is, once you dig out the tar, asphalt, or whatever it was "protecting" the electronics, and manage to repair the thing, what is a good modern substitute to put back in the device?

Put up a pic of what you are attempting to repair and maybe someone can help...

I once had to rebuild the power supply of an Atwater Kent 44 radio. I kept all the tar that I carefully scraped out of the power module. After replacing the paper-foil capacitors, I melted the tar and poured it back in to conceal the repairs. I don't know what to recommend for a new potting compound.

As far as a modern substitute to refill the switch, most modern ones are epoxy filled...

Thanks. The repair was the easy part, now I just need to fill in the "tar" I didn't keep any, but I can probably locate something else around the place with enough to melt back into the new one. I don't want to use epoxy as I think it would be nearly impossible to open it again should anything else break.

Why not use candle wax?

Curt A wrote:Why not use candle wax?

I think the low melting point combined with the high operating temperature of early electronics would likely be disastrous.

Never thought about the heat part... I guess it could cause some type of surprise. Typically, any switches that I have messed with don't give off heat, unless defective, but what do I know...

Curt A wrote:Never thought about the heat part... I guess it could cause some type of surprise. Typically, any switches that I have messed with don't give off heat, unless defective, but what do I know...

I wasn't referring to the switch giving off heat necessarily. I suppose I based my comment on the assumption that said switch was attached to something containing one or more of these, which do give off heat:

Those are out of my experience level... if something doesn't wind up, I try to avoid it...