Soldering problem. Can't get it to stick.

[MattAnonymous]

Hey guys, it's been a while since I've posted and it seems a lot has changed.

I'm in the process of finishing the guitar I've been building (pic below).  The only problem is that I can't seem to get the pickups backplates to solder to the covers.  I've sanded, cleaned, and fluxed to no avail.

Any tips would be much appreciated.



Thanks,
Matt

[R.G.]

Soldering large pieces of metal is different from soldering small ones.

(a) Do you have enough heat?
(b) Were these originally soldered? What metal are they - presumably not aluminum?
(c) Is it possible that you sanded off a plating layer that was solderable?

[petemoore]

I've used, in degrees of succes...
  750w soldering *Gun [lots of output and contact with this, so works good, use solder between tip and piece to transfer the heat, allow it to heat until the solder melts from touching only the piece right next to the tip.]
  Electric Stove burner...funky and way too much radiant heat, but will allow soldering temps, just set the joint area so it's touching the burner and use a long solder strand or leather glove, outside preferably, we have an exhaust fan....not exactly recommended
  Propane Torch [the heat is most concentrated and the carbon is least concentrated at the tip or above the flame, heating one side and soldering the other may work some, the carbon that propane deposits often prevents solder stikking.
  Propane torch heats 'some tip' like of an old heavy iron...don't immerse the tip in flame, heat behind the tip so the carbon doesn't get to the conduction area, get a big enough mass of 'tip' material hot enough and it'll heat the sheet.
  Huge Industrial Iron [may be workable, but slow
  35w Iron [forget it
  Getting a right angle soldered is tricky, I'll type about that.
  on the one piece I may cut and bend a 1/32'' 'tab' [the smallest I can get with a cutter so that there's a tab 'catch' at the edge of the sheet that catches on the other sheet edge] that touches the top and end of the other sheet, and duct tape [back from where it's gonna get real hot] the two pieces together, then solder that tack together first.
  But for the first one I like 'tieing or sewing it together with copper wire, through little holes , then do the second tack using the tab align method [or..hold it somehow aligned], and tack solder the tab area first, so when I continue the pieces align and meet.
  The sheets Around where you're soldering should be 'floating', and clamping [don't clamp there] around there conducts thermal mass that cools where you want the heat to rise quickly.
 
 

[Skreddy]

Go to a really bad part of town and visit a liquor store.  You should be able to find a cheap little butane torch for sale that's probably used for smoking crack.  Ideal for little soldering jobs that require more heat than an iron will supply, I used one to solder 1/4" jacks to some 6v outdoor lighting wire (great speaker cable).  The extra heat might rainbow your chrome or nickel plating.  Just buff it out with chrome polish if so.

[Paul Perry (Frostwave)]

An alternative might be to abandon solder altogether, and use a short piece of wire to connect the pieces together, with conductive epoxy (as used to repair heater wires on car demisters). That would take care of the groundign issue, and then use some kind of glue to hold the top on. DISCLAIMER: just an idea, nobody would ever let me near a guitar.