# Solder won't stick



## kous (Apr 12, 2007)

I am having problems getting the solder to stick, especially with connecting the wires to the tremolo claw, pots, and switch. I think the problem is that all the parts are new. I cleaned the surface to free any dust and oil. I also scratched the surface a bit to expose the metal underneath the surface. But no luck. Any help would be greatly appreciated.

Thanks!


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## ronmac (Sep 22, 2006)

The problem may be that you are not using enough heat (wattage rating of iron may be too low). For an effective solder joint the metal contact points need to be hot enough to melt the solder and allow it to flow freely. If the solder is being melted by direct heat from the iron itself you will not have a good bond.


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## Wheeman (Dec 4, 2007)

Use the flux, young padawan, use the flux!

Seriously, a dab of flux makes life that much easier. It does its own chemical cleaning and flux + lead/silver solder = happy solder.


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## PaulS (Feb 27, 2006)

If you don't have flux use a small piece of sandpaper or a file and clear a spot on the place you wish to solder.


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## keeperofthegood (Apr 30, 2008)

Although I think this is a very low probability, stick a magnet to the metal.  if it fails, you could be soldering onto white metal or aluminium both of which are not going to happen with any great ease (and I have encountered aluminium with pot shells, rare but happens).

Heat (really important if you are using lead free solder, and if you have silver in the solder it will require more heat too), the right flux (gosh I was 9 when I used acid core on an audio transformer :/ what a mess it was a few days later!!), well sanded solder points are all important too. Time as well, you need everything to stay still until the solder has cooled to the point it is no longer liquid or you could be pulling your wires right back off or causing weak cold solder connections.

Another thing to try is to tin your solder points same as tinning the iron. This also aids in then connection wires next.


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## greco (Jul 15, 2007)

keeperofthegood said:


> Although I think this is a very low probability, stick a magnet to the metal.  if it fails, you could be soldering onto white metal or aluminium both of which are not going to happen with any great ease (and I have encountered aluminium with pot shells, rare but happens).
> 
> Heat (really important if you are using lead free solder, and if you have silver in the solder it will require more heat too), the right flux (gosh I was 9 when I used acid core on an audio transformer :/ what a mess it was a few days later!!), well sanded solder points are all important too. Time as well, you need everything to stay still until the solder has cooled to the point it is no longer liquid or you could be pulling your wires right back off or causing weak cold solder connections.
> 
> *Another thing to try is to tin your solder points same as tinning the iron*. This also aids in then connection wires next.


+1 to all the above. 

What is your iron's power rating (in watts) ?

Dave


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## kous (Apr 12, 2007)

Thanks for the replies guys, 

I have a soldering paste, which looks like Vaseline. I think this is the flux. The solder I am using does not contain lead. 

Concerning the wattage of the soldering iron, I heard that anything higher than 60-70 could cause damage to the part. I don't know the power of my solder (it is rather cheap) but it is enough to melt the solder. Can you elaborate on the solder being melted by direct heat? 

I am pretty sure the parts are solder-able (?) since they are specifically guitar parts.


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## mhammer (Nov 30, 2007)

1) Solder flow is a function of the rate of heating vs the rate of heat dissipation. The bigger the surface or part, the faster it dumps the heat you're trying to foist upon it with your soldering iron. Poor solder flow = cold joint.

2) What makes a part/surface perpetually shiny is not necessarily what makes for good solder adhesion. Same way that what may have a great surface for adhesion *under* all that grime and tarnish doesn't necessarily provide a good joint either. I often use a utility knife or equivalent to scrape away a bit of the shiny surface to permit better solder adhesion to what's underneath.

3) A small $10 bottle of solder flux is a wonderful addition to any workbench. make tinning things so much easier, and if you apply a bit to solder wick when unsoldering, the solder wick works 5x better.

4) For really big things, sometimes the answer is not to solder to the object, but to solder to something which you can *secure* to the object. So, for instance, if you canot solder to the pickup switch, then solder to a small washer which is *secured* to the switch with a screw/bolt.


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## Guest (Sep 10, 2008)

mhammer's liquid flux did my solder joints on pots and jacks a world of good. The flux will not steer you wrong.


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## Spikezone (Feb 2, 2006)

Sometimes it helps to heat the component (potentiometer casing or terminals, for instance) and melt a small daub of of solder to it, then do the same for the wire you are going to attach, then it only takes a short burst of heat to join the two together securely.
-Mikey


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## kous (Apr 12, 2007)

Thanks for the advice everyone.
I'll try things out.


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