are potentiometers very heat sensitive?

[[email protected]]

It seems like I keep damaging the pots when I'm rewiring them in my
electric guitars or my amps. I'm assuming the heat from my soldering
iron is wrecking them. But I'm surprised they would be so sensitive to
heat. The hottest iron I use is 40 Watts.

 

[Andrew Holme]

It seems like I keep damaging the pots when I'm rewiring them in my
electric guitars or my amps. I'm assuming the heat from my soldering
iron is wrecking them. But I'm surprised they would be so sensitive
to heat. The hottest iron I use is 40 Watts.

Wrecking them how? How long are you applying heat for? It shouldn't take
more than 2 or 3 seconds per joint.

 

[Anthony Fremont]

Wrecking them how? How long are you applying heat for? It shouldn't take
more than 2 or 3 seconds per joint.

He's probably talking about soldering ground leads to the metal can of
the pot for shielding. Using a 40W iron, it takes a long time to get
the metal hot enough to solder to. He needs a trigger type gun in the
140W range. This will get the metal hot enough in short enough time to
prevent damaging the pot. Of course the lugs only need the smaller
iron.

 

[[email protected]]

shouldn't

He's probably talking about soldering ground leads to the metal can of
the pot for shielding. Using a 40W iron, it takes a long time to get
the metal hot enough to solder to. He needs a trigger type gun in the
140W range. This will get the metal hot enough in short enough time to
prevent damaging the pot. Of course the lugs only need the smaller
iron.

Actually, I AM talking about soldering the lugs. I don't think I'm
applying the heat too long. But sometimes when I'm done, the pots
don't work quite right. Sometimes they cut out while turning them.
Replacing them always seems to work.

Recently, I had a pot on my guitar amp that I took out and put back in.
When I was finished, the volume wouldn't turn off and the it didn't
behave the same. So I replaced it with another pot then it worked
fine.

 

[Rich Grise]

Actually, I AM talking about soldering the lugs. I don't think I'm
applying the heat too long. But sometimes when I'm done, the pots
don't work quite right. Sometimes they cut out while turning them.
Replacing them always seems to work.

Recently, I had a pot on my guitar amp that I took out and put back in.
When I was finished, the volume wouldn't turn off and the it didn't
behave the same. So I replaced it with another pot then it worked
fine.

Dirt.

Especially if you're using old, surplus, or recycled pots.

This kind of pot is notorious for intermittent connections. It isn't
soldering heat, it's just crud between the element and wiper. Get some
proper potentiometer cleaner spray, sometimes called contact cleaner,
or contol cleaner, or the like - look for something guaranteed to leave
no residue.

But just plain old ordinary dust in the air can cause this kind of
behavior in potentiometers. (I'd have said "pots", but didn't want
to open the thread to the bean cookers. ;-) )

Good Luck!
Rich

 

[Bob Masta]

Actually, I AM talking about soldering the lugs. I don't think I'm
applying the heat too long. But sometimes when I'm done, the pots
don't work quite right. Sometimes they cut out while turning them.
Replacing them always seems to work.

Recently, I had a pot on my guitar amp that I took out and put back in.
When I was finished, the volume wouldn't turn off and the it didn't
behave the same. So I replaced it with another pot then it worked
fine.

I wonder if these might be conductive plastic pots?
You might want to pry open one of the damaged ones
and see what it looks like under the hood. If this
doesn't tell you at a glance what is happening, you
could then experiment by soldering the connector
and watching what happens. If it's not actually
melting the polymer, it might be causing it to exude
something non-conductive to the surface.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

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