Solder on Pot Cases

[rojo412]

You can use these, clamped between the pot and mounting area. If you string these together with the main ground, you'll avoid soldering to the pot casing. Just test all items needing to be grounded for continuity, before putting it back together.

(but properly soldering to the casing is fine, too, once you get the hang of it)

 

[Rabidhamster]

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.

You’re on the right track! I assume they also recommended a good eutectic electrical solder for that. Some pots are really finicky, the pots from radio shack you’d have to score pretty deep to get a connection. But for new CTS pots I just use some flux, I prefer the liquid but paste rosin works too. You can get a whole blob of solder on your iron just as you apply. Isopropyl or everclear qtips cleans it up after

 

[JeezyMcNuggles]

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.

Because audio pots are universal hardware. They aren't exactly made for guitars. They're used in guitars. They have various uses and functions.

You can easily just bend the right node to the pot, and solder it there, then just run your grounds into the actual pin holes instead of the pots. But, you have many grounds to connect, and the holes aren't exactly an easy point to run multiple wires.

The reason you can get it to stick though, is because you're not getting it hot enough. Hold your iron on the pot casing. Feed a decent drop of solder down on it. Stick the wires on the lump, and heat the lump. Let off. Done.

 

[40Hz]

27710888[/URL], member: 284122"]Can use a simple short piece of cable

Or a piece of solid copper wire, or a clipped off resistor or capacitor lead…or anything else you have handy that’s conductive. I often use a capacitor lead since I’m usually wiring up a complete harness and I salvage a piece to use from the tone cap.

 

[rojo412]

Those work great. And if you find yourself running out of that and doing a LOT of wiring, you can get BUSS WIRE in thin gauges which is perfect for these applications.

 

[Wfrance3]

I use solder that has 15% silver content and I also use liquid flux. Both for electronics obv…
+1 on having soldering iron hot enough.

 

[Wasnex]

It's not just about how hot the tip of the iron is....it's also about how much thermal mass the tip has. When you place the tip on the pot case, there is a transfer of heat energy. This means while the pot case heats, the tip cools. If the tip does not have enough thermal mass, it will not be able to give off enough energy to sufficiently heat the pot case.


You indicated you are using WE1010NA . I believe the included tip is fairly small and more suitable for working on circuit cards. Probably something like this:

If you have not already done so, try a bigger tip:

Another potential problem, potentiometers may be plated with material that is not really suitable for soldering. AFAIK, you may need to do a bit more than just rough up the surface of the plating. You may need to scratch through the plating to get the solder to stick.

Possibly the best solution is selecting a pot that is plated with a material that takes solder well.

 

[skycruiser]

I agree they should have tabs, or at least a high quality tab option for diy folks. Assembly line workers don't care. The know exactly how to solder to the case. I have broken pots by overheating them.

 

[HoHumbucker]

It's not just about how hot the tip of the iron is....it's also about how much thermal mass the tip has. When you place the tip on the pot case, there is a transfer of heat energy. This means while the pot case heats, the tip cools. If the tip does not have enough thermal mass, it will not be able to give off enough energy to sufficiently heat the pot case.


You indicated you are using WE1010NA . I believe the included tip is fairly small and more suitable for working on circuit cards. Probably something like this: View attachment 5154970

If you have not already done so, try a bigger tip:
View attachment 5154971

Another potential problem, potentiometers may be plated with material that is not really suitable for soldering. AFAIK, you may need to do a bit more than just rough up the surface of the plating. You may need to scratch through the plating to get the solder to stick.

Possibly the best solution is selecting a pot that is plated with a material that takes solder well.

Yes, indeed, I have a selection of tips. I am using one of the bladed ones for this.

 

[HoHumbucker]

When making a P-Bass wiring harness, I'll take a large paper clip and unbend it so that it is straight and cut to size. Then solder it to both pots. This serves as a common ground that you can use for the remaining ground wires avoiding any further soldering to the pots. It also will prevent a pot from rotating if the nut comes loose.
View attachment 5154437

I really liked this idea, so put it to use. The photo isn't the best, but you can see that I straightened a paper clip, formed it around the pot, laid flux paste around the sides of the pot, then wicked the solder between the wire and the pot. Seemed to work pretty well. Not the prettiest job, but seems to be holding.

I then attached the common wires like "birds on a wire". This tidied up the cavity pretty nicely. It also still shows my garbage attempts at soldering the wires directly to the case. My apologies in advance if my work traumatizes anyone. Once I got this all soldered up, I did plug into an amp and it all works just fine.

Thanks everyone for the ideas, help, and encouragement. I really appreciate it. My skills still have a long way to go, but I do certainly know what I need to practice on now.
Next, replacing the pickups.

 

[Spectre Gunner]

To OP: I think you did a great job with that. As long as it holds, conducts electricity and works as intended is what's important, so I'd consider it a success. One thing you are achieving by connecting all the grounds (as feasible) to a common point is known as "star" grounding which is a good thing.

 

[JfetPre775]

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.

 

[JfetPre775]

Perhaps a bit late to this discussion.. But reading through the comments I felt that you (the op). Or maybe someone else who’s been soldering for a bit and searching the threads trying to figure out what the heck they’re doing wrong.
Oftentimes novice’s (particularly novice musicians) getting into electronics despite putting in the practice, believe that they are the problem. It’s something I struggled with early on, inexperience & lacking any kind of “real” electronics background/training lead me to wonder “man, am I really cut out for this stuff? Maybe I need to stick with the subjective type artsy/creative musical stuff which comes naturally??”
(*Nowadays I design audio circuits for pro recording equipment. But I have a fairly large box of about 15 fully wired & assembled amplifier & guitar pedal stripboard /PCB’s that I couldn’t ever get working!)

Here’s the thing~The relative ease & speed of any soldering project VERY dependent on the type & quality of your soldering pen/iron, OR ideally digitally temp controlled adjustable soldering station w/several different sizes & shapes of tips the best you can afford. Yep, unfortunately the filthy 5$ or even 30$ amazon Chinese special soldering pen or the dirty old one you borrowed from your buddy which you hold solder to for hours and never melts.. That’s your problem not your ability level! Irons & Fancy Stations like the Hakko fx888d which made soldering effortless aside, There are other things that can make a pretty big difference to your work;
1) Rosin activated RA & High activity water soluble (careful this need to be cleaned) Fluxes in liquid or paste form can really speed up wetting time and flow, plus makes very strong shiny joints. So many ways this stuff can be used and can be so helpful for stubborn alloys or tight areas you’ve already soldered (like grounds on the back of those persnickitty push/pull Bass-potentiometers!!)
2) A newer fully functional nicely cleaned & tinned tip! The cheap irons fluctuate between low>high heat so much that the stress burns up even the best cared for tips. Partially damaged, corroding tips, or anything that doesn’t accept solder super easily over the entire active surface goes in the trash.. I would buy all the tip tinners/cleaners to try reviving the many tips I went through and even spent 12-15$ on a tip which I would then put on a 12$ soldering pen.. I’d need a new tip every time I soldered!! My Hakko station I mentioned before kept the exact same tip for about 6 years of every day use in absolute pristine condition!!!
3) Some may disagree with this; But regardless of the Iron, tip, fluxes, temperature’s etc.. Avoid kitchen sponges soaked with cold tap water at all costs!! The bad chemical makeup of tap water is reason alone, the dirty sponges, but particularly the temperature fluctuations from heat drops caused by the cold water.. can destroy tips. I love the tip cleaner copper wire balls like Hakko & others offer. Keeps your tip temp stable, only takes one pass to entirely clean, and has fluxing & tip rejuvenating powder in it. Why not??
Ps; after I said all that, The type of potentiometers you mentioned can actually give me trouble as well.. It’s the way they’re manufactured and the solder unfriendly alloy they use that makes them such a pain in the ass..

 

[HoHumbucker]

Perhaps a bit late to this discussion.. But reading through the comments I felt that you (the op). Or maybe someone else who’s been soldering for a bit and searching the threads trying to figure out what the heck they’re doing wrong.
Oftentimes novice’s (particularly novice musicians) getting into electronics despite putting in the practice, believe that they are the problem. It’s something I struggled with early on, inexperience & lacking any kind of “real” electronics background/training lead me to wonder “man, am I really cut out for this stuff? Maybe I need to stick with the subjective type artsy/creative musical stuff which comes naturally??”
(*Nowadays I design audio circuits for pro recording equipment. But I have a fairly large box of about 15 fully wired & assembled amplifier & guitar pedal stripboard /PCB’s that I couldn’t ever get working!)

Here’s the thing~The relative ease & speed of any soldering project VERY dependent on the type & quality of your soldering pen/iron, OR ideally digitally temp controlled adjustable soldering station w/several different sizes & shapes of tips the best you can afford. Yep, unfortunately the filthy 5$ or even 30$ amazon Chinese special soldering pen or the dirty old one you borrowed from your buddy which you hold solder to for hours and never melts.. That’s your problem not your ability level! Irons & Fancy Stations like the Hakko fx888d which made soldering effortless aside, There are other things that can make a pretty big difference to your work;
1) Rosin activated RA & High activity water soluble (careful this need to be cleaned) Fluxes in liquid or paste form can really speed up wetting time and flow, plus makes very strong shiny joints. So many ways this stuff can be used and can be so helpful for stubborn alloys or tight areas you’ve already soldered (like grounds on the back of those persnickitty push/pull Bass-potentiometers!!)
2) A newer fully functional nicely cleaned & tinned tip! The cheap irons fluctuate between low>high heat so much that the stress burns up even the best cared for tips. Partially damaged, corroding tips, or anything that doesn’t accept solder super easily over the entire active surface goes in the trash.. I would buy all the tip tinners/cleaners to try reviving the many tips I went through and even spent 12-15$ on a tip which I would then put on a 12$ soldering pen.. I’d need a new tip every time I soldered!! My Hakko station I mentioned before kept the exact same tip for about 6 years of every day use in absolute pristine condition!!!
3) Some may disagree with this; But regardless of the Iron, tip, fluxes, temperature’s etc.. Avoid kitchen sponges soaked with cold tap water at all costs!! The bad chemical makeup of tap water is reason alone, the dirty sponges, but particularly the temperature fluctuations from heat drops caused by the cold water.. can destroy tips. I love the tip cleaner copper wire balls like Hakko & others offer. Keeps your tip temp stable, only takes one pass to entirely clean, and has fluxing & tip rejuvenating powder in it. Why not??
Ps; after I said all that, The type of potentiometers you mentioned can actually give me trouble as well.. It’s the way they’re manufactured and the solder unfriendly alloy they use that makes them such a pain in the ass..

Thanks for your thoughts and suggestions. Quality gear is nearly essential for this I know.
- My brother is a EE university professor and lab instructor. My soldering station, solder, and flux come at his recommendation.
- I do have a variety of tips, and they are in good nick. With the solder station, this should be less of an issue than the pencil irons, but I am keep an eye on how well I can keep it tinned.
- I have one of the copper cleaning stations on order. I have been using a sponge with water so far. I do also have a small container of the tinning rejuvenation powder. Have used that a few times to tidy up the tip.
- I appreciate your sharing that these pots can be more challenging. But If I can make it work on the hard stuff, the easy stuff should be more easy, eh?!?

 

[JfetPre775]

Thanks for your thoughts and suggestions. Quality gear is nearly essential for this I know.
- My brother is a EE university professor and lab instructor. My soldering station, solder, and flux come at his recommendation.
- I do have a variety of tips, and they are in good nick. With the solder station, this should be less of an issue than the pencil irons, but I am keep an eye on how well I can keep it tinned.
- I have one of the copper cleaning stations on order. I have been using a sponge with water so far. I do also have a small container of the tinning rejuvenation powder. Have used that a few times to tidy up the tip.
- I appreciate your sharing that these pots can be more challenging. But If I can make it work on the hard stuff, the easy stuff should be more easy, eh?!?

Yes absolutely! Although, part of my point was that for some the fussy difficult project is their last. I know the combination of not successfully completing the project. Along with melting/destroying the 18$ dual-stacked pot I couldn’t figure out how to choose a replacement for almost pushed me out (I had no clue what audio, anti-logarithmic taper, center-detent 500k/250k ohms split knurled shaft meant when I started!!). To be honest I was posting in response to you, but also in the hopes my advice might reach someone who’s stuck. Searching through old forum threads for help/answers 10 months whatever down the road. Like I did years ago..
It actually sounds like you’re really fantastic shape!! An EE lab level quality digital station and industry standard supplies ..you may be in better shape than I am and I do this professionally!!

One thing I wish I’d pointed (more for the general community than you specifically) was how important leaded solder was.. Especially if you can afford a high quality flux core 63/37 eutectic alloy wire, like the kester 44 rosin core 63/37 solder I use. The 63/37 eutectic type alloy melts at a significantly lower temperature than the common 60/40 type.
Oh, and also using isopropyl alcohol and a toothbrush to clean & prep surfaces.. That ridiculous wives tale I see folks posting all the time about scraping or gouging the backside casing of potentiometers only makes things worse! -Ok I’m done, I’ll get off my soapbox now!

 

[HoHumbucker]

One thing I wish I’d pointed (more for the general community than you specifically) was how important leaded solder was.. Especially if you can afford a high quality flux core 63/37 eutectic alloy wire, like the kester 44 rosin core 63/37 solder I use. The 63/37 eutectic type alloy melts at a significantly lower temperature than the common 60/40 type.
Oh, and also using isopropyl alcohol and a toothbrush to clean & prep surfaces.. That ridiculous wives tale I see folks posting all the time about scraping or gouging the backside casing of potentiometers only makes things worse! -Ok I’m done, I’ll get off my soapbox now!

I had not been cleaning with IPA, but will going forward (I keep a bottle of Everclear around for my 3D printer farm cleaning).
Actually the Pb-Sn eutectic is at 61.9% so both the 63/37 and 60/40 are off-eutectic composition, but in different directions. They are fairly close in liquidus temperature, but the 60/40 has a wider mushy zone and will partition just a bit more than the 63/37. At these cooling rates, that should not make a huge difference. There may be some whetting or surface tension characteristics that are different between the two alloys which may make one or the other flow better as a liquid.
I have decided not to use Pb solder for now (Sn-Ag-Cu instead). Yes, the Pb-Sn does work better for many applications, but I spent a chunk of my career working with literal tons of molten lead, and I prefer to limit additional exposure.

 

[JaymoLobo]

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:

That solder joint doesn't look good to me. And contrary to what others have said, a good solder joint is nice and shiny, and has good "wetting" to all items in the joint. In the case above, your wetting is poor, and the conductivity may be poor relative to what you want, particularly when it comes to good grounding.

 

[walterw]

I have decided not to use Pb solder for now (Sn-Ag-Cu instead). Yes, the Pb-Sn does work better for many applications, but I spent a chunk of my career working with literal tons of molten lead, and I prefer to limit additional exposure.

then that will be an additional hurdle to overcome to get reliable solder joints, the lead-free stuff is much harder to use (certainly not worth it for non-industrial use IMO, you're not slaving over a hot iron all day every day)

the other "secret trick" not mentioned so far is creating the "solder bridge", where you put enough solder on the iron tip to create a hanging liquid droplet right before hitting the work; this greatly speeds up heat transfer, much like oil in a frying pan speeds cooking

this solder bridge droplet is not the solder that will make the joint because the flux inside it will have cooked out already, but when you use it to apply the heat while feeding in fresh solder you should be able to get nice joints even with an iron that isn't that great

put it this way, i don't bother with anything besides soldering to pot backs because with the right technique it's fast, easy and reliable

 

[Passinwind]

It's not just about how hot the tip of the iron is....it's also about how much thermal mass the tip has. When you place the tip on the pot case, there is a transfer of heat energy. This means while the pot case heats, the tip cools. If the tip does not have enough thermal mass, it will not be able to give off enough energy to sufficiently heat the pot case.


You indicated you are using WE1010NA . I believe the included tip is fairly small and more suitable for working on circuit cards. Probably something like this: View attachment 5154970

If you have not already done so, try a bigger tip:
View attachment 5154971

Another potential problem, potentiometers may be plated with material that is not really suitable for soldering. AFAIK, you may need to do a bit more than just rough up the surface of the plating. You may need to scratch through the plating to get the solder to stick.

Possibly the best solution is selecting a pot that is plated with a material that takes solder well.

+1. I also have a spool of some special Kester solder for metals that don't take solder well, I will have to sort through my disaster area of a shop to call the exact spec though. I use a 70W Hakko iron with a 4mm screwdriver tip for anything with a big ground plane area, it makes things much much easier. Something like a 2.4mm chisel may be safer for civilians though.

Edit: it's this stuff: 331 Flux-Cored Wire
Which you must clean up after rigorously, preferably with warm deionized water.