Solder problem...

[Axtklinge]

I'm trying to melt solder to do some rewiring in my guitar, but it seems the solder doesnt agree, and wants to stay in place (aka it just doesnt melt).

I'm using a small (30W) soldering iron, which as far as I can tell is work fine (it melts the solder I use for small home work), but doesnt scratch the solder in the guitar.

Any idea how many Watts I might need to melt "Fender solder"?

[milocj]

Try adding some "fresh" solder to the original unmelted solder as you're heating it up.

[jwells393]

I have a Ungar 45 watt iron and have never had your problem.

[gtech]

Don't forget that the more metal you have to heat, the higher the wattage you need.

45W is indeed better, specially if you want to solder on lugs or on the back of the pots.

[Axtklinge]

Originally Posted by gtech

(...) specially if you want to solder (...) on the back of the pots.

And thats exactly were I started, as it was the more exposed zone.

Edit : I've just called a friend who seems to have a 80W iron.
Should I use it, or is there any danger of "frying" pots, caps, or else?

[superlightweigh]

I had the same problem. What you don't need is more watts. What you do need is flux. Spread a little on that blob, get your tip tinned, and it will melt like buttah.

There is a danger of damaging caps from too much heat applied in the wrong way.

[1293]

Originally Posted by Axtklinge

I've just called a friend who seems to have a 80W iron.
Should I use it, or is there any danger of "frying" pots, caps, or else?

I wouldn't use it to solder a cap, but it would be good for soldering wires to the back of the pot. With more watts, the solder will melt quicker and the pot will probably heat up less than with a lower watt iron applied for a long time.

[Vizcaster]

Could you explain how flux is meant to help de-solder? I thought flux was meant to etch the metal so that solder will stick to it in the first place, I didn't know that it was supposed to do anything to the solder itself when you're melting it to remove it.

Incidentally I agree that 30 W can be a little weak for solder blobs on the backs of pots, and some manufacturers use higher temperature solders. I wouldn't worry too much about cooking the pot (although it's really the amount of time you apply heat that is a problem, not the power of the gun, so it's like stir frying - use a lot of heat and get out fast). However you might want to put a heatsink clip or hemostat onto the wire you're desoldering so the heat doesn't migrate back and melt the insulation or the cap as the case may be.

[gtech]

Exactly what they say. You use more heat and can go faster by heating just what you need.

If you use not enough heat, it takes so much time that the whole pot is getting warm and absorbing the heat.

[superlightweigh]

The flux definitely does more to help the heat to flow from the tip of the iron- I've found that by keeping the tip tinned and painting on a fresh coat of flux to the blob on the back of the pot, I can liquify the whole thing in about two seconds with a 40-watt iron.

(I did not learn this through trail and error, but from getting Terry Down's DVD- he's on the TDPRI)

Since watching a master do it, I've gained more skill in two to three weeks than in all the years leading up to that point.

[jrfrond]

- Higher heat-less hang time

- Clean tip (make sure you have a wet sponge to wipe it on)

- Clean solder surfaces (get yourself a little wire brush and clean the leads. SCRAPE the back of pots with a small screwdriver or knife blade.

Electronic solder has a flux core, and extra flux should not really be needed. However, when working on old connections, using a bit of flux or melting a little new solder into the old will help it to reflow.

Flux helps to boil-off impurities, it does not etch. Metals can build up an oxide layer over time that is inpenetrable by chemical means, making the wire brush treatment necessary on occasion.

[Axtklinge]

Latter today I'm gonna to try out my friend 80W iron.
Lets see how it goes.

Thanks you all for your help!
Cheers
Axt

[Axtklinge]

Job's done.
But let me tell you that it was no easy task even with the 80W iron!!!
The solder simply took huges ammounts of time to melt, only to instantly get solid again a fraction of second latter.
I'm not that experienced, but it was nothing like I've ever seen.

Anyway it was very difficult to "undo" the factory job, but afterd that the rest of it was quite simlpe.

Thanks you all for your input!
Cheers
Axt