Weird Problem - Solder Won't Melt

wyvern84 · #1 05-09-2009, 02:56 PM

I got some new pickups for my Fender MIM Jazz Bass, the Dimarzio Model J's (DP123). I wanted to install them myself, so I did a lot of research and I'm fairly certain I know enough to do this.

So I take off the pickguard and control plate, plug in my soldering iron, and get out the desoldering braid. I know which connections I have to desolder, so once the iron is heated, I start to desolder the old pickup. I put the braid on the connetion and heat it up. Nothing happens. It is my understanding that the solder should melt when I heat it and the braid should suck up the solder. I even put the iron directly on the connection for a few seconds to see if I could melt the solder, but I get nothing.

The only thing I can think of is that it's not hot enough. I'm using a 30 watt iron, which I've read should be enough for any guitar work. It's very capable of melting the rosin-core solder I bought for this job. I can only assume they must have used something very different to wire it in the first place.

Do I need to buy a stronger iron? I've read that you don't want anything stronger than 30 watts for guitar work so you don't damage anything. Causing any damage is the last thing I want.

pbassturk · #2 05-09-2009, 03:01 PM

Dude, I've been a mechanic for a looong time and I have personally NEVER heard of solder Not melting when heated(rosin core or not). Are you sure your on the glob of solder and not on the component?

spideyjg · #3 05-09-2009, 03:03 PM

Something sounds whacked to me. Typically a 30 watt iron is the exact tool you need.

However recently solders have changed formulations to reduce lead and these solders are more of a challenge to work with.

Typical solder irons get to 700F I use one that is adjustable and can go quite a bit higher but I set it to about 700.

Do some digging on low lead solders to see what iron would be needed.

Got flux?

Jim

wyvern84 · #4 05-09-2009, 03:06 PM

I do have flux, but I'm not sure how that will help when the solder won't even melt.

Nick Kay · #5 05-09-2009, 03:12 PM

Some soldering irons have to warm up for a good five minutes before they'll melt anything. Some connections may require more than a few seconds of direct heat to melt. Make sure the tip of the soldering iron is attached tightly and tinned.

wyvern84 · #6 05-09-2009, 03:25 PM

I've tried to tin the tip, but the solder just falls off. Could the tip be dirty? It's definitely not very shiny.

jtc_hunter · #7 05-09-2009, 03:31 PM

Take some sandpaper to the tip and clean it well, then try again after the iron has had 10 mins. to warm up.

Ric5 · #8 05-09-2009, 03:34 PM

It depends on the mass of the lead to be melted. If the glob is too big then it will be hard to melt.

Or perhaps you need a new soldering iron.

Nick Kay · #9 05-09-2009, 03:35 PM

Quote:

Originally Posted by wyvern84

I've tried to tin the tip, but the solder just falls off. Could the tip be dirty? It's definitely not very shiny.

Quite possibly! As jtc_hunter said, take some sandpaper to the tip (a finer grit, 400 at the lowest), take off any carbon char and corrosion, then go over it with some steel wool and try tinning again. You're never going to get results if your tip won't hold solder from tinning.

wyvern84 · #10 05-09-2009, 03:37 PM

Quote:

Originally Posted by Ric5

It depends on the mass of the lead to be melted. If the glob is too big then it will be hard to melt.

Or perhaps you need a new soldering iron.

Whoever soldered this originally did use huge gobs of solder. If that's the problem, do I just need to hold it on longer?

MagicMan_841 · #11 05-09-2009, 03:38 PM

I think another part of the problem is that the pots and control plate (if you haven't taken the pots out of it) act as a giant heat sick that absorbs enough heat to prevent the solder from melting.

Cleaning the iron will definately help, though.

VisualShock · #12 05-09-2009, 03:40 PM

clean the tip of your iron until it shines, nearly to the point of seeing your face in it. then start again. dab your iron in a wet sponge whenever you get solder on it, and then wait for it to heat up again.

Bubba Ghanoosh · #13 05-09-2009, 03:42 PM

I always let the iron warm up, then wipe off the tip before tinning it. Also, it may be hot enough to melt the solder by itself. But to desolder, and for a proper solder joint, it should be able to heat up the solder, wire and solder point.

I use a 60W soldering station w/adjustable heat and set it for the lowest temp required for the job.

+1 on what Magic Man said about heat sink.

wyvern84 · #14 05-09-2009, 04:35 PM

Is there anything I can do about the pots being a heat sink, or do I just have to deal with it?

dmusic148 · #15 05-09-2009, 04:47 PM

You just have to deal with it. As stated, clean tip and tin it. If that doesn't work, it's new iron time. Yours may just be a POS.

Rocky McDougall · #16 05-09-2009, 05:47 PM

I really like the higher power soldering irons because they heat the spot (on the pot) to be soldered much quicker and the full body of the pot does not get as hot. Also I use a small puddle of solder to transfer heat faster. Keep a damp cloth pad close by and wipe the tip of the iron frequently to clean the tip. Also as others have said, sand or file the tip of the iron to clean it well before starting.
.

fusoid · #17 05-09-2009, 06:07 PM

Sometimes you need to prime the wick a little bit to get the flow going. Before dumping a lot of heat on the joint, try to see if you can even melt any solder into the solder-wick by itself... Also, sometimes its better to cut the wire away from the joint before attempting to remove all of the solder, as long as you have enough length to redress the end. When soldering, its good to work as quickly as possible, especially with vintage components.

wyvern84 · #18 05-09-2009, 08:10 PM

I finally managed to desolder two of the wires, the two connected to the "legs". The two directly on the pots just have way too much solder. I can't melt it. Is there any way around this?

walterw · #19 05-09-2009, 08:15 PM

try flowing in a little new solder, which might help transfer heat and melt the old.

also, a good quality soldering iron tip would be immediately ruined by sanding it.

if you can't get solder to flow onto the iron itself, it'll do you no good on anything else. clean (don't sand) the tip, replace the tip or get a better iron.

nboyer941 · #20 05-09-2009, 08:28 PM

Clean the tip with steel wool or a wire brush, not sand paper.

Also, I'm not sure about the irons. Whenever I solder I use a 150 watt soldering gun and the solder will melt right away and not do any damage. This way is fast, clean and easy. A dual temp 150 watt, craftsman gun at Sears is like $45. It heats up and is ready to go in 10 seconds.