solder not sticking??

[Psych0F0x]

That does work - until the solder that attached to the wire only begins to corrode and oxidize in the unwetted area between it and the lug it's mechanically attached to.

Unless you get the LUG AND THE WIRE clean enough to wet with solder and hot enough to melt the solder all by themselves, wrapping the wire in the lug will eventually cause an intermittent joint. That may take a long time, but it will happen.

There are no non-cleaning ways to solder properly. Either it is clean enough for the flux to finish the cleaning, or it won't make a good solder joint.

Thanks, I never cease to learn more stuff on this board.

[petemoore]

How powerful is your soldering iron?
  This has alot to do with it.
  OT: I cheat
  w/cheep-o iron, I have a 'Grille Lighter', I set the flame for about 1''+, heating/getting carbon all over *behind the tip, this super heats even the worst of irons. Fast work makes all this easier, hot is the temp to choose if the iron can handle it. Not recommended, use only the tip of the flame for greatest concentration of heat/highest temperature/most complete carbon combustion. The flame is hotter/cleaner at the tip or just above. Propane torch is even better/more dangerous/harder to work with, {OT though, I sometimes greatly prefer a valved torch fuel controller, and the ablity to still buy them. Sometimes what I have is a 'tepid' iron, and with a lighter I can proceed now. Mind that you do not want carbon on your tip or in the solder joints !!
  I have a honkin' 16'' industrial Iron, gets plenty hot, can melt lug mess in 1 second, I use it for sheet copper/solder connections.
  Bear in mind the main variables you've got with the physical soldering iron that affect how quickly it transfers heat:  temperature and surface area.    If you lay an entire side of the iron along the surface you're trying to wet, you can transfer substantial amounts of heat even at a lower temperature.  It's almost exactly the same as the relationship between voltage differential, electric resistance, and current, except instead of electricity you're dealing with heat.
  Great Points!!
  Thermal Mass is going on big time, variances in...:
  Heat conduction
  Temperature of iron, and 'to be soldered to' materials, Also: the SOLDER
  Thermal Mass of the Iron and 'to be soldered items'
  Solder 'temperature and amount' is a big one. Just Enough solder to conduct heat to the metals...then let the conduction occur by NOT adding more solder UNtil the conduction has allowed the metals to rise to soldering temperatures...then accounting for the further cooling the 'new cold' ..solder added to provide structure to the joint.
  A whole lot of mashed solder on an inadequately heated jack lug is a fairly common sight. A tepid iron and copious amounts of solder is the method used to achieve: needs cleaned up, and heated properly so it can be re-flowed.

[coffyrock]

great helpful ideas here. I was having trouble keeping my wire and lug together while holding the iron, so I started making the wire into little hooks and putting it on the lug. Now I've got a solder-stand thingie with alligator clip holders so I essentially have the third hand I was missing. Now I'll steer clear of the hook-wires and any eventual durability problems... thanks for the tip!

Going to get some liquid flux tomorrow!
I love this board! 

[davph30]

Hi There. Usually ruffing up the surface and putting some solder on it and some on the wire first helps.

[SolderBoy]

I don't recommend sanding parts.  The reason is that you may get molten solder to harden and stick to it, but it won't actually be making a proper solder joint.  I recently repaired an active bass that had pots that were obviously held on a belt sander or a bench grinder or something prior to originally being installed.  If fact, they actually had scorch-marks on them!  The bass was 10 years old and I just popped off the wires from the pots with my fingernail.  The parts sould be clean, sure - I always have a bit of steel wool handy to shine up grey parts, but scratches may lead to the false impression that you have a good joint.

A few years ago I bought a cheap 80Watt iron for these sort of jobs.  As RG says - you can get in there and get out again very quickly.  Its great for pots and also for neutrix plugs and sockets - especially the sleeve on their right angled plugs.  Its good for tinning thick cables and also for soldering those automotive spade terminals etc. etc.   It has a very big tip, so you couldn't use it on anything delicate, even if you wanted to.

I only ever use flux when I have no choice but to tin both parts.  This happens when I have both hands full with a difficult installation in a guitar or something and I know that I'll have to fudge good soldering technique and melt a blob of solder on the iron first.  By the time you get to the parts, the rosin in the solder has burnt away.

[R.G.]

I don't recommend sanding parts.  The reason is that you may get molten solder to harden and stick to it, but it won't actually be making a proper solder joint.

That happens when the contact is a base metal that does not solder easily or perhaps does not respond well to the type of flux in the solder you're using. Sanding removes the plating that would otherwise wet easily and you're left with a difficult-to-solder base metal.

Steel wool, especially 0000 is about the right amount of abrasion for tough cases. Generally, a pencil erase or a typing eraser (do they even make those anymore?) is abrasive enough to remove surface oxides.

[343 Salty Beans]

I don't recommend sanding parts.  The reason is that you may get molten solder to harden and stick to it, but it won't actually be making a proper solder joint.

That happens when the contact is a base metal that does not solder easily or perhaps does not respond well to the type of flux in the solder you're using. Sanding removes the plating that would otherwise wet easily and you're left with a difficult-to-solder base metal.

Steel wool, especially 0000 is about the right amount of abrasion for tough cases. Generally, a pencil erase or a typing eraser (do they even make those anymore?) is abrasive enough to remove surface oxides.

+1 to the erasers. I don't exactly have steel wool on hand here, so I chanced it with a pencil eraser, figuring 'what the hell? it's only a 5 x 7 piece of vero anyhoo'. Worked like a charm.