Solder on Pot Cases

[HoHumbucker]

I have a Gretsch G2220 that I am hoping to install some TVJones Thunderblades on. But I am getting stuck trying to solder to the cases of the new pots I ordered with the P/Us. Taking a break to research what I may be doing wrong and why the solder and wires won't stick to the back (I have cleaned and sanded the case).

Then a question popped into my head. If there are so many folks using the case as a common, why do they not install tabs connected to the case to make that soldering easier? Maybe the answer is that the expected skill level for this task exceeds my current capabilities. If anyone has any trick to share, I sure would appreciate it. Thanks in advance.

 

[Geri O]

You want to be careful here, but make sure your soldering iron is hot enough for soldering wire to the case. It takes a little more heat for that than just soldering wires together.
But as with all soldering work, you want the iron to be just hot enough to do the job.

 

[Inertialsky]

Tin the wire with a little solder. spread a tiny bit of solder on the clean/scuffed back of the pot. Once they're both tinned it should be easy to bond them.

If you're using cheap solder that could be part of your problem.

Youtube is your friend. there's plenty of tutorials on this topic.

good luck

 

[SharpCat]

+1 on not-cheap solder. Make sure it's rosin-core, not the acid-core used for plumbing or no-core. Put a dab on the soldering iron tip just before starting to use it so there's fresh rosin. It burns off after just a bit.

 

[BassLife77]

I use ring terminals and solder to those

 

[SharpCat]

I use ring terminals and solder to those

I like that idea. Thanks!

 

[ChristoMephisto]

I prefer solder tabs over soldering to the back of pots, on my Bass VI none of the pots are grounded, only the jack"s on the plate is connected to a common point in the cavity. I have no extra hum beyond the single coil 60Hz hum

 

[themickster]

I have a Gretsch G2220 that I am hoping to install some TVJones Thunderblades on. But I am getting stuck trying to solder to the cases of the new pots I ordered with the P/Us. Taking a break to research what I may be doing wrong and why the solder and wires won't stick to the back (I have cleaned and sanded the case).

Then a question popped into my head. If there are so many folks using the case as a common, why do they not install tabs connected to the case to make that soldering easier? Maybe the answer is that the expected skill level for this task exceeds my current capabilities. If anyone has any trick to share, I sure would appreciate it. Thanks in advance.

You need to get the pot up to the right heat for the solder to flow.

 

[Deleted member 271037]

I prefer solder tabs over soldering to the back of pots, on my Bass VI none of the pots are grounded, only the jack"s on the plate is connected to a common point in the cavity. I have no extra hum beyond the single coil 60Hz hum

The pots on your Bass VI are definitely grounded, from pot chassis' through the metal control plate to the jack chassis/sleeve. If the pots weren't grounded you wouldn't get any sound at all.

This works fine as long as the pots are firmly connected to the control plate of course but it's only a mechanical connection and it can't be trusted. If the pots or jack are slightly loose (which can easily happen, typically during a gig...) you may experience crackling and dropouts. In my experience it's always a good idea to solder ground wires to the pot chassis' on Bass VIs.

As for the OPs problem it's probably a matter of using enough heat and a suitable soldering tip. Cheap, low wattage soldering irons and/or small soldering tips can be problematic when soldering to a pot chassis. With more heat and a suitable soldering tip you can get a good connection within a fraction of a second. Faster soldering = much less risk of damaging the pots. I actually ruined a pot once, because I used a poor quality soldering iron and had to apply heat for too long.

 

[ardgedee]

All that metal on the back of the pot is serving as a heat sink, wicking the heat away from your soldering iron. That's why it's more difficult to solder that than to solder the wire.

Make sure you have the the right solder for the job. To make your life easier it should be rosin core and intended for electronics. Do not use plumbing solder!

You could keep the iron resting on the pot until it's hot enough but that comes with a high likelihood of damaging the working bits. When soldering you want to expose things to the soldering iron as little as possible.

So if you have a soldering iron with adjustable temperature, try a higher temp and work more quickly. If the joint doesn't take, let things cool down before trying again. Also try using ring terminals instead, like suggested above.

Also, don't worry too much about making your work attractive. If there is a gnarly pile of solder on the back of the pot, that's fine -- the solder can be re-melted infinite times (as long as you keep the heat from reaching the working bits of the pot). Don't keep adding more. You can always clean up after you're done.

 

[Tommy Sparks]

All good advice.
I use a 45 watt pencil type iron and have since 1979 when I started electrical school.
Definitely higher heat and more quickly. I’ve cooked a couple of pots myself over the years.
Buy a little tub of resin and put it on the pot before you start soldering.
Good luck.

 

[HoHumbucker]

Thanks for the input everyone. Looks like I may just need more temperature and practice.
-I understand about the heat sink issue. I can see the pool quench almost immediately (recommended temperature your find works for you?)
- I do have electronics rosin core solder. I figured that plumber's solder and a blow torch was likely not the right job for this
- Using a WE1010NA station. recommended to my by a EE lab director
- I am indeed trying to work quickly and not damage the underlying components
- Ring terminals? you mean like ring/spade I would use in automotive wiring? Bare terminals? crimp connector? solder the ring end to the pot? or leave the ring out for the wire connections?

I really appreciate the help. I know I will get better with practice, but I would like to be practicing the right skills.

 

[40Hz]

Others have already mentioned the importance of using quality solder and proper soldering technique. So I won’t repeat it. However, adding a drop of flux to the pot will make for a better flow when you’re soldering to it.

This is a trick I found useful for wiring volume pots:

 

[HoHumbucker]

Others have already mentioned the importance of using quality solder and proper soldering technique. So I won’t repeat it. However, adding a drop of flux to the pot will make for a better flow when you’re soldering to it.

This is a trick I use for wiring volume pots:

Wow, that is a great idea. The initial pot had a wire soldered like that. I had not thought to hang the other wires like laundry on a line. Will try that for sure. Thanks for sharing that one.

 

[40Hz]

27709725[/URL], member: 387738"]Wow, that is a great idea. The initial pot had a wire soldered like that. I had not thought to hang the other wires like laundry on a line. Will try that for sure. Thanks for sharing that one.

You’re welcome. His channel has some other good ideas. Worth a look.

One side note: if you bought a pot that is specifically sold as a guitar pot, check the manufacturer’s specs to see if the case is already tinned before scuffing it. RS Guitarworks and a few others are selling CTS pots that come that way and can be soldered to directly. Scuffing those pots undoes the tinning and defeats the purpose.

 

[HoHumbucker]

One side note: if you bought a pot that is specifically sold as a guitar pot, check the manufacturer’s specs to see if the case is already tinned before scuffing it. RS Guitarworks and a few others are selling CTS pots that come that way and can be soldered to directly. Scuffing those pot undoes the tinning and defeats the purpose.

Thanks for this. I bought the pots from TVJones when I got the P/Us. I will take a look.
Yes, indeed, he does appear to have some stuff I could learn from on his channel. I appreciate the pointer.

 

[kgbeast]

I always shield the cavity with conductive adhesive copper tape, then I use that shielding as common.
You would need a slightly more powerful soldering iron to solder to the pots. I have a simple orange handle Weller ron which is probably 20-25w iron. It would take minutes to heat up a pot case which is bad as all other parts of the pot will get too hot. I just make sure that the pot makes contact with the tape and then use copper tape shielding for the common. It is very easy to solder to. Works great and leaves the pots clean if the solder blobs.

 

[Aloe]

I had problems wiring to backs of the pots when I used a 40w iron. with a 60w iron everything is okay.

be sure not to overheat the pot, as already noted.

 

[Killing Floor]

The pencil solder irons from the hardware bin at Walgreens don’t get hot enough.

 

[Rolling Thunder]

Tinning is winning. Put a small amount of solder on the case and let your iron heat up the case as you're soldering. You want flow, not BB-sized beads (a sign of cold surface). Good luck!