De-soldering a huge blob on the chassis

[MikeMcK]

This is a pretty non-technical question, but if anyone can answer it one of you can...

I'm trying to remove a multi-section cap (caps-in-a-can). It has four ground lugs soldered to the chassis with huge solder blobs. I tried everything up to using two separate 100W solder guns to try to get the first lug loose, but no luck. Any advice?

[smolder]

If it is factory solder it might be a high temp blend. It sounds odd... but I have had luck using lower temp solder on top and as it mixes the other solder softens. The real problem is the chassis is one giant heat sink.

[zzmoore]

A small propane torch, like a plumber uses to solder copper pipe.

[Trout]

I use a nice freshly sharpened craftsman 3/8's inch wood chisel and a tack hammer.(Low Impact)
You can cut the solder off really easy flush to the chassis surface no heat required.

BTW, if your tossing the cap, you can cut the tabs off with the chisel. I have done this several times. Those cans are very soft steel and cut like butter.

I have used a dremel a couple times, but I found it pretty messy and it was a PITA to clean up all the metal shavings.

[Blue Strat]

When desperation sets in I'll grab a multicap can with a big pair of pliers and wrestle it off. It's amazing how easily those tabs unsolder afterwards. ;)

[jbltwin1]

Big honking old soldering wand that takes about 20 minutes to heat up. When THAT fails, I have a couple of old externally heated irons that are heated with oxy-acetylene torches that we used to used MANY years ago when we repaired gas tanks with little copper patches and solder. DAMN, I'm old. In a pinch, you can heat the end of a cold chisel with the propane torch and loosen it that way. Steel cools quick so don't muck around.

[MikeMcK]

Thanks, all. I think I used a little bit of each of those ideas. Between the little torch and the chisel I had that thing off in about five minutes (not counting the trip to Home Depot).

Thanks again.

[slider313]

A 175 watt iron sold at pluming supply stores; like Blackman. They do sell some cheap 150 watt Chinese ones on ebay.

[mbratch]

I use a nice freshly sharpened craftsman 3/8's inch wood chisel and a tack hammer.(Low Impact)
You can cut the solder off really easy flush to the chassis surface no heat required.I've used this method. It's simple and effective.

[AL30]

Try using a very wide tip for the iron. You probably need more surface area to disperse the heat better.

AL

[Mike9]

If you're gonig to reattach something to that spot the plumbing iron is what you need - mine is like 200 watts.

[Trout]

If you're gonig to reattach something to that spot the plumbing iron is what you need - mine is like 200 watts.


I have one of those, " The Bertha 200" can be used for branding cattle also :AOK

[mbratch]

I have one of those, " The Bertha 200" can be used for branding cattle also :AOK
LOL - that's funny! :D

I have a soldering iron that goes up to 1100 degrees or something like that. With a medium tip, it still takes a bit of finesse, persuasion, and patience to get the chassis solder spots off. I am regretting the day I sold my Weller soldering gun at a yard sale.

[stoo]

Cut-off wheel in a Dremel tool.

Stew

[mark norwine]

Good heavens people! Torches? Chisles? Ripping it out with pliers?

This is why you own / keep a Weller 200W gun.

It's all about thermal mass & surface area. And wick. Lots of wick.

[jbltwin1]

I myself have never used a torch on the amp itself. I HAVE used the torch to heat a mechanical soldering wand(no internal heating of it's own). I usually don't use wick when I have a blob but it DOES work. I suck it up since the big irons will puddle it. Like Mark says, Chisels? No way. Unless you're heating it up of course. I HAVE done that.

[Dave C]

I too have used a sharp wood chisel and light hammer until I got this. It's an ancient Stanley 140w iron with a massive tip that takes a while to heat up...but when it's up to temp...it can melt and hold a very large blob of solder in a liquid state very easily
http://i83.photobucket.com/albums/j310/kemo6178/DSC_4046cs2.jpg

[rockon1]

You need one of these. Good for HD stuff. If you hold the trigger long enough the tip will glow red hot! Bob

http://i35.tinypic.com/2q3qhw5.jpg

[stratman_el84]

For the majority of heavy stuff I use a Weller D-550 dual-heat 200-260 watt gun. Takes only a few seconds to come to temp when the trigger is pulled, and cools quickly too. It will take care of 90% of the heavy stuff like multi-section chassis-mount cap cans.

That, along with solder braid and a 'solda-pullt'-type solder-sucker tool usually does a clean, relatively quick job. You use the solda-pullt to remove the main body of the blob, then the braid to clean it up to where the tabs will break free with a slight twist with a pair of needle-nose pliers, then just straighten the tabs enough to pull the can out.

For really really heavy stuff I have an ancient old 360 watt pencil-type plumbers' iron with a huge, massive tip & body with a big old wooden handle that takes about 30 to 45 minutes to come to temp. Not much will stand in the way of that monster. Not much finesse with that thing though, and definitely not an option where room to work is limited.

Cheers!

Strat