Grounding Question

[Turk 182]

I am trying to do the wiring for an H-S-S, 5 way switch, one volume, one tone, with split humbucker configuration on a guitar and I have a question about the wiring for ground. The schematics found on this site say to solder several of the wires to the tops of the pots as a ground, but I am having trouble getting the solder to hold on the pots...it just slips off so the wire doesn't stay. It is a stop tail guitar and has a piece of heavy wire (about as heavy as a clothes hanger wire) connected to the body, probably to the tailpiece because it is coming out into the wiring cavity and it is not an electrical wire-its just a heavy piece of metal-I am assuming this is there to be used as a ground wire.

My question is, do you think if, instead of connecting everything the schematics say to solder to the tops of the pots labeled as "ground", i connected those wires to this piece of heavy wire I am referring to, it would serve the same purpose? Is there something special about using the tops of the pots as a ground that I am not aware of?

 

[Metalblaze]

Re: Grounding Question

The top of the pots must be grounded as they are wired like that (caps, shorted lugs to ground etc).

Maybe if you scratch the surface of the pots before you solder could help. Also wait until the back of the pot heats up with the solder (and wire) in place. Once it heats up you'll see the solder to spread. THat means a good solder joint.

I would suggest to use a more powerful soldering iron but you need to be experienced as you have to make everything faster. I've used a 75W one which is quite powerful but I could swap pickups in no time with it. You just have to be more careful.

btw welcome!

 

[ehdwuld]

Re: Grounding Question

scuff the back slightly

once your surface becomes heated enough
the solder will "flow"
large pots are difficult to heat because you have to heat the entire pot

a larger soldering iron just increases the chance of scorching the pots innards

I have used a 30 watter for years

 

[GuitarDoc]

Re: Grounding Question

You should roughen up the area to be soldered with steel wool or sand paper. A soldering flux may also be helpful.

Actually, a high wattage soldering iron will potentially cause less damage to a pot or circuit than a low wattage iron. The reason being...you want to get a lot of heat to a small area in a short duration of time. This keeps the heat at the soldering site.

With a low wattage iron, you will need to keep it in contact with the pot for a longer period of time to get it up to the heat required to cause the solder to flow onto the metal. This increased time allows the heat to spread to the more heat sensitive components of the pot, potentially causing damage to the pot.

So the key is, heat a small area as rapidly as posible. Once the solder begins to flow, you're done. Don't "dink" with it. It also helps to use a heatsink to absorb the excess heat and keep it from spreading. This can be, simply, with your wire snips pressed against the metal right after removing the iron.

 

[TheLivingDead]

Re: Grounding Question

All of this is good advice... But I have to ask, I've recently been told to NEVER scuff the surface of the pot. That in doing so, you're actually scraping away what would help the solder to stick. Any truth to this? I've been scuffing for years with no problems but now I feel weird doing it.

 

[GuitarDoc]

Re: Grounding Question

No truth to that, unless you scrape all the way through the metal.

You are only "cleaning" the surface of the pot, not necessarily roughening it. Solder won't stick to rough dirty/oxydized metal, but it will stick to clean smooth metal.

 

[Turk 182]

Re: Grounding Question

Thanks for all the advice everyone. I'll give it another try tomorrow.

 

[uOpt]

Re: Grounding Question

You only have to connect to ground somehow. If the pots all sit in a conductor such as a shield inside a Strat pickguard they are all connected and connecting one of them to ground does the trick, or connecting the shield to ground any other way.

The practice of soldering to the back of the pot is wrong in the first place. These things are supposed to be grounded from being put into a metal chassis. It's just stupid electric guitar hacks that brought this practice, which often damages the pots, forward.

 

[Jeff_H]

Re: Grounding Question

Actually, with some of the new CTS pots and those from RS Guitar Works, I have read that they already have a solder like layer of material on them and scratching it off will make it harder for the solder to stick. I'll have to dig around and see if I can find the actual link I read.

I'm sure that does not pertain to all pots everywhere, but I don't know what percentage of CTS pots have this material on the back.

 

[TheLivingDead]

Re: Grounding Question

Actually, with some of the new CTS pots and those from RS Guitar Works, I have read that they already have a solder like layer of material on them and scratching it off will make it harder for the solder to stick. I'll have to dig around and see if I can find the actual link I read.

I'm sure that does not pertain to all pots everywhere, but I don't know what percentage of CTS pots have this material on the back.

Yeah! Pretty sure that's what I heard too.