Pots for MOIST environment

[Mo'Phat]

I jump around when I play and tend to sweat quite a bit. That moisture is corroding my electronics - to the point that copper wire is corroding and breaking at the solder joints. Are there any potentiometers that are sweat resistant? Maybe sealed pots rather than the traditional open ones?

Are there any preamps that use aluminum wire?
Are Dunlop Super Pots any good?
Or is there a method to 'waterproof' the control cavity and the shaft of standard pots?

Modulus FU4 with a Bartolini humbucker and 3-band preamp currently loaded.

I'm willing to swap out preamp/pots/wiring and do whatever would work to keep the moisture out of the electronics.

/for the record, I'm not an unusually drenchy sweater, but we play humid spots all summer and the sweat just happens.

 

[sloppy_phil]

Can you identify what part of your arm is making the most contact with the electronics? Is it your fingers when you touch/turn the knobs, or maybe your arm rubbing up against them? Because if it's from your arm at all, you could look into wearing a sweat band (or three) to absorb the excess moisture before it gets to the electronics.

FWIW, this is the first I've ever heard of an issue like this, so not exactly coming at you with field-tested advice! But then, sweat bands are meant to, well, absorb sweat, so it seems an obvious first move.

Also FWIW, I have not heard of any moisture-resistant bass electronics. Perhaps not unrelated to this also being a problem I've never heard of anyone having before.

 

[Snert]

Are there any preamps that use aluminum wire?

Al oxidises nicely too so I'm not seeing a point in using it. It's also horrible to solder and I'd never trust it.

Or is there a method to 'waterproof' the control cavity and the shaft of standard pots?

There are plenty of pots available from brands like Bourns that are sealed and usually much higher quality than what you find in MI gear. I've been using them in various electronics projects for decades for devices that are far more critical than a bass on stage with no issues. Try Mouser and Digikey. The main problem you might have is finding knobs you like that fit some of them.

 

[Bruce Johnson]

You can waterproof your control harness. There are pots available which are closed and sealed. In the basses I build, I use pots made by PEC, a Canadian company, which I buy through DigiKey. These are heavy duty sealed pots, mil-spec rated, made for military electronic gear. They aren't horribly expensive, like $11 each.

You can also buy liquid insulating paint at the hardware store. A little can of black goop with a brush in the lid. It's used by electricians to seal up connections against moisture. Get your joints all soldered neatly and tested, then paint the goop on there. It will make the joints approximately water tight. It's more mess the next time you need to unsolder something. You have to peel the stuff off the joint.

We Luthiers don't generally waterproof our harnesses, because corrosion isn't much of a problem for most instruments. But if you are seeing real corrosion in your bass, then you can waterproof it.

 

[Snert]

You can also buy liquid insulating paint at the hardware store. A little can of black goop with a brush in the lid.

There are a variety of electrical potting compounds used in devices that are used in applications, usually industrial, that need to perform in harsh environments. You can also use epoxy if you want it permanent.

I also don't recall the last PCB I've seen that wasn't coated.

 

[Bruce Johnson]

Well, sure, you can cast the whole harness in potting epoxy, if you really want to. But that's nearly impossible to repair later.

This is the stuff I'm talking about: Liquid Electrical Tape. Lots of different brands available; here's one from Amazon:

https://www.amazon.com/Star-brite-L...pY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

It's dumb and simple and it works. And you can actually remove it to make repairs. Peel it back with a knife, resolder the joint, slop some more on. It's not real pretty cosmetically, but it does the job of sealing out moisture.

 

[BassCajon]

How can you stop the moisture from getting into the cavity in the first place?
If moisture is going through the knobs, you could try some rubber o-rings under the washers or even inside where the wood meets the metal.
I'm thinking you could also pack the wire hole in the pickup cavity with some cotton or something to stop moisture from creeping in. You can also closely inspect under the rear panel for discoloration or deposits too to see where your sweat might be getting in.

 

[sleddogn]

dang if that much water is rolling off you, maybe trip to doctor is needed? lol, j/k

 

[Zooberwerx]

IIRC, this was a Jason Newsted problem with his Sadowsky basses. Big question: how is the moisture wicking into the pots and control cavity? Is it following the path of the pot shafts or holes themselves? The cheapest and first approach would be to add a barrier of some ilk just to pinpoint the culprit. Here's a strange and stupid idea: Remove the knobs and add appropriately-sized rubber O-rings on the underside. Replace the knobs and re-position on the shaft so the knobs turn with some resistance. Even dumber: throw some desiccant packets in the control cavity. Any chance moisture is being introduced via the control cavity margins?

Oh, almost forgot: If sweating...and dripping...profusely, there's a good chance the sweat is entering the pickup cavities and following the leads to the control cavity.

Riis

 

[Jefenator]

I remember reading about Newsted's Sadowskys and how he got them sweat-proofed. I can't remember exactly what they did. Maybe silicone? Maybe a rubber O ring with the jack. Whatever they did was pretty thorough - IIRC they tested one by dunking it in a bathtub. (I might let the control cavity drain & vent via some downward facing cranny.)
You might be able to Google what they did - or re-engineer something similar. Sealed pots sound like a good idea for redundancy.
Also maybe book your summer tours in Canada.

 

[fig]

...I'm not an unusually drenchy sweater, but we play humid spots all summer and the sweat just happens.

I get it. I had a gig at a tiki bar that was very hot in the afternoon. In Florida, on second floor under a thin tin roof, directly over the kitchen. Miserable and tiring heat.

Dripped sweat from my arm and hand down the bass body. Wore two sweat absorbers (cut-off sleeves from old T-shirts), one on my wrist, one near the elbow. Weird to see, but worked for me. Also a fun conversation starter when on breaks LOL. I used my beater bass (and stand-by amp) for that gig, 'cause of the corrosive salt air environment, so I didn't wipe the bass after every gig. Next day was salty trails and splotches from dried sweat LOL. The sweat absorbers stopped that.

So if just your arm is the culprit, you might consider sweat absorbers for now to prevent some sweat intrusion as a partial solution. You can always continue looking for better liquid proofing solutions as mentioned in the thread.

 

[Zooberwerx]

I remember reading about Newsted's Sadowskys and how he got them sweat-proofed. I can't remember exactly what they did. Maybe silicone? Maybe a rubber O ring with the jack. Whatever they did was pretty thorough - IIRC they tested one by dunking it in a bathtub. (I might let the control cavity drain & vent via some downward facing cranny.)
You might be able to Google what they did - or re-engineer something similar. Sealed pots sound like a good idea for redundancy.
Also maybe book your summer tours in Canada.

The key word here is "barriers". Granted, the OP will have to replace any damaged components (pots?) but other key components, including preamp board, are just as vulnerable. Water follows the path-of-least-resistance. I would imagine just about any potential pathway can be addressed with items-on-hand (bathtub caulk) or material readily available at Lowe's...no StewMac needed here! I'm still leaning heavily towards introduction via the wiring channel(s). Water adheres to the wire and follows like it would on a water pipe. The terminus: the pots.

Riis

 

[Mo'Phat]

OP here - thanks for all the suggestions, everyone. Sweat is from arm, head and chest. I'm in a RHCP tribute, so plenty of bare skin and non-stop movement for a 2 hour show 4-5 days in a row. I wipe down arms and bass between tunes when I can, but can't catch it all.

I will look into what Newsted did - I also seem remember reading something about Tim with Rage needing to take similar measures. I saw Newsted twice and although he was obviously in tremendous physical shape, he was still drenched by mid-show.

I will silicone the wire chases to the pickups, look into O-rings or just silicone the knob holes, and check out sealed pots. Insulating paint on the solder connections is a great idea. I've now had three copper connections corrode and break off the pots and have to be resoldered.

 

[Jefenator]

It sounds like an extra inspection & maintenance routine will be a good idea, regardless of what solution you implement.
At very least, I would probably look in the control cavity to see what's going on before each season or tour - even if that meant having to redo some silicone seals.

 

[Zooberwerx]

OP here - thanks for all the suggestions, everyone. Sweat is from arm, head and chest. I'm in a RHCP tribute, so plenty of bare skin and non-stop movement for a 2 hour show 4-5 days in a row. I wipe down arms and bass between tunes when I can, but can't catch it all.

I will look into what Newsted did - I also seem remember reading something about Tim with Rage needing to take similar measures. I saw Newsted twice and although he was obviously in tremendous physical shape, he was still drenched by mid-show.

I will silicone the wire chases to the pickups, look into O-rings or just silicone the knob holes, and check out sealed pots. Insulating paint on the solder connections is a great idea. I've now had three copper connections corrode and break off the pots and have to be resoldered.

Sometimes you just have to think like a plumber: plumber's putty or little wax rings for the control holes, caulk the surround...if it's a major leak, I'll borrow my buddy's ProPress kit.

Riis

 

[bigdaddybass12]

I get it. I had a gig at a tiki bar that was very hot in the afternoon. In Florida, on second floor under a thin tin roof, directly over the kitchen. Miserable and tiring heat.

Dripped sweat from my arm and hand down the bass body. .

Yes on this, same situation, we had an afternoon gig, west facing stage, august, southwest Alabama, sweat was running down our arms and legs. Not much jumping around for us.

 

[fig]

Sweat is from arm, head and chest. I'm in a RHCP tribute, so plenty of bare skin and non-stop movement for a 2 hour show 4-5 days in a row. I wipe down arms and bass between tunes when I can, but can't catch it all.

Well, that makes my cutesy little arm absorbers idea pretty much useless LOL. Besides, those arm absorbers would be visually distracting when you're doing the portion of your RHCP show wearing just a sock. Tribute bands gotta tribute

I wonder if Flea, or his techs, do any sweat-proofing of his basses.

 

[MidlifeBeginner]

I work for an electronics company. Gear we design spends years outdoors in every environment, including jungles.

Whatever you do, you want to still be able to take things apart to clean. Two primary objectives are reduce the amount of water getting in, and dry up what water gets in. The DC voltage of active electronics will drive corrosion.

Salt only corrodes when water is present. Unfortunately, enough salt build up will pull water out of humid air.

• Sealed pots are a good idea.
• Get silicon grease to put on threads and nut of the pots after install. It keeps the threads from rusting and can fill in tiny gaps water might follow. Dielectric grease can reduce rust formation on any metal.
• Seal around the pickup with something. Maybe frog painters tape. It is ugly, but would be easy to put on and peel off.
• In the control cavity, put in desiccant packs. You routinely have to change them out, depending on how well things are sealed.

 

[Mo'Phat]

Desiccant packs! Great idea. Even those gel humidor dehudifiers would work.

I usually just eat them, like the packets say

/kidding.

 

[MidlifeBeginner]

I like the ones with the color change beads. You can dry them in your oven to reuse.

The beads can handle quite a bit of heat. Beware the the glue on cheap packs might come undone in the oven. It is a narrow temperature range to dry and not melt glue.

You can buy the beads and make your own packs by stabbing a bunch of little holes in ziploc bags. Dump the beads out in a pan to dry. Ziploc bags aren't compatible with an oven.