very freakin annoying noob q

rightintheface

Senior member
Messages
326
alright. so i've wired up my electronics as best i can. HOWEVER. i can't bloody work out how to attatch a decent blob of solder to my pots as a ground. the stuff just slips right off. ive tried sanding the bottom of the pot a little, for a bit of grip ( ???), but it's still not working. any suggestions? i'm not sure the exact composition of the solder i am using. the silver kind  :icon_tongue:
 

jimh

Senior member
Messages
1,344
Sometimes you can find that some types of solder wont take as well to some types of metals as they do others (I must say I'm not too familiar with silver solder).  Also bear in mind that the back of the pot is quite a bit larger that most other solder connections.  It'll act like a heat sink, and dissipate the heat more than just the end of a piece of wire or solder tag.  This obviously means it'll take longer to heat up enough for the solder melt and bond to it.

Also, As I think you were getting at, some pots have a kind of lacquer on them which obviously wont create a metal to metal / electrical bond.  But as you say, you've roughed up the back so you should be OK.

You've got a couple of options........If you've got a low power (15-20W) soldering iron you'll have to leave the iron touching the back of the pot for longer in order for it to heat up enough for the solder to take.  Bear in mind that if you hold it on for too long, you could overheat the whole pot, and potentially damage the wiper or the tracks.
The other option is to try to find a slightly more powerful (hotter) iron.  Around 30-45W.  This will obviously heat up to a higher temp.  This'll mean that the area on the back of the pot will get hottter quicker, the solder will take to the pot easier, hopefully without the heat spreading too much to the rest of the pot and damaging the tracks.

Hope that helps.
Let us know how you get on.
 

Orpheo

Senior member
Messages
2,738
I had the same trouble, but I got my pots from Warmoth. what I did was to sand down the pot to the bare metal. there is a sort of a 'film' of some kind on the pot, and that prevents proper soldering on the back of the pot. just sand it down until it shines, and then you're ok to go!
 

jackthehack

Senior member
Messages
5,630
Funky Phil said:
Just use CTS pots and a decent iron...no need to sand or file the back.

There are many models of CTS pots; the short shaft ones sold at GuitarElectronics.com, for example have a dull metal finish to the back/sides and solder sticks to them easily. The long shaft ones that Warmoth sells are long enough to fit through rear route control holes, but have chromed backs. If you don't sand/file/dremel the chrome finish off the back as needed, you're likely to burn the thing up before you get any solder to stick to it.
 

DiMitriR33

Senior member
Messages
604
hotter iron, the pot needs a bit of heat before the solder will adhere. also you need solder sutable for that much heat, the real fine stuff for circuit boards can work but usually turns all black.

some might disagree but i like to use a 45watt iron or hotter for the pots, gets things hot quickly so you can get done quickly and less potential damage to the pot. but for a beginer a 30 watt iron should be hot enough to do the job and will not be as likely to damage the pot if it is heated and re-heated several times, or kept hot for an extended period.
 

Phrygian

Senior member
Messages
459
Look, why is is that so many say use a big gun, and they never mention flux.  Some rosin paste flux will help tremendously (it prevents oxidation), especially at higher temperatures.
 

Orpheo

Senior member
Messages
2,738
jackthehack said:
Funky Phil said:
Just use CTS pots and a decent iron...no need to sand or file the back.

There are many models of CTS pots; the short shaft ones sold at GuitarElectronics.com, for example have a dull metal finish to the back/sides and solder sticks to them easily. The long shaft ones that Warmoth sells are long enough to fit through rear route control holes, but have chromed backs. If you don't sand/file/dremel the chrome finish off the back as needed, you're likely to burn the thing up before you get any solder to stick to it.

I really think, no, know, that this is the answer to the problem. one you sand away the chrome, you can solder it within 5 seconds. I know I can, with my 15w (!!!!) soldering iron.
 
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