[jarroyo]

Hello,

New to these types of restorations and I am having a heck of a time desoldering the old caps. The radio is a 47-1230 and it is pretty crammed in there and the lugs have globs of solder on them. I have done PCB board desoldering before, but trying these is a battle. I have tried pumps and wicks, but I am having a heck of a time. Any tips or tricks you can offer? I am about to just say "forget it!" and either j-hook all these suckers or something more drastic.

Any help appreciated.

[morzh]

If you've done PCBs and your soldering was good, it's not that different.

First, keep in mind you need bit more power. So, your iron should be at least 40W.
Those Weller PES51 / WESD51 solder stations are usually good. I use it.


Second, you need long narrow needlenose pliers. You grab the lead and start unwinding as you heat it up. Usully works well.

Third. Be judicious wioth the amount of heat applied to backelite tube sockets.
Forth. Be especially judicious with the same when unsoldering a cap (or anything) from a coil / RF transformer.

So, keep your tip clean, and always have a droplet of solder on it. Use flux, it hepls.

And, practice makes perfect.

[RodB]

I use a solder sucker, but before I start using it I unscrew the tip and wrap the tip threads with Teflon tape, then reassemble the tip for a sealed fit and more suction.

[morzh]

Rod, which one do you have?

[MrFixr55]

If the wiring and soldering is good, I am not opposed to J-hooking, especially if you are stuffing caps. Personally, J hooking is mandatory if you are going to stuff paper caps, as you can seal the hook inside the cap and it will look like you never changed them (or disturbed the wiring).

If dealing with decayed wiring, especially rubber, then you need to desolder at the sockets. Use the steps recommended by Rod and Morzh

[RodB]

Mike, this one:

https://www.amazon.com/Teenitor-Solder-S...hdGY&psc=1

Just a cheapie.

[morzh]

Oh...I thought you were talking about some electromechanical one.
I have the same one. Or the same type (for regular jobs).
You mean, wrapping the threads in theflon actually makes the difference?

Mine has metal cap, these seem to have plastic ones.

But yeah, can't beat 3 for 7 bucks...

Mine has lasted me at least 15 years, I am down to 2nd tip.
Thing about them, they develop the plug every 15-20 sucktions, so have to be unscrewed and the plug pushed out. If I had to wrap it in theflon every time, that would be a bit onerous. But mine does not seem to suffer from the lack of suction.

[Arran]

I used to use a bulb, but had to drill out the hole in the tip to stop it from clogging, eventually the bulb part got old, and the rubber started to crack, so I switched to a "Solderpult" type sucker, which is less awkward but not by much. What I do to remove old caps is suck the solder off the terminals first, then clip the lead off on end of the old cap, then heat the terminal again and unwind the old lead. In Philco sets the terminals on the tube sockets are spade shaped and don't have holes, so you can unwind them, sometimes you need to undo something else wound on top, which isn't typically too hard, picks, or small screw drivers can be useful for getting these apart. It's just something that takes practice, and a hot iron, or gun.
Regards
Arran

[morzh]

Arran

I do exact same technique.

[RodB]

I also have a deluxe IBM unsolder tool. It has a forked end and a point end with a wood handle. I've used others but they are made of cheap metal and plastic. This one seems to be indestructible but I'm very careful with it.

[radiorich]

Hello Arran,
I also work on Philco radios and have been using the "Solderpult" since the 1980s! Like you mentioned, it’s easy to unwind the leads after cutting them off, and I use picks and needle-nose pliers as well.

Sincerely Richard

[morzh]

Well...while Hakko does indeef use some plastic, I would not call it made cheap.

[radiorich]

Hello morzh,
I agree with Hakko is good stuff most japanese tools and audio gear is well made .
Sincerely Richard
P.S. I want to get a Hakko desoldering station .

[MrFixr55]

Radio Shack used to make a desoldering iron, about 40 W, tip had an orifice and bulb for vacuuming while heating.  One of these days, I will hook up to a vacuum pump.

   

[DaleHCook]

I use a Metcal Model SP440 vacuum desoldering station, but large blobs of solder on a lug may clog the first filter in the Metcal. In those cases I use a vacuum pump desoldering tool (Radio Shack 64-2098) to remove most of the solder, and the Metcal, often with additional heat, to clean up. Heat and long-nose pliers help to remove wires.

I used to own an iron which combined a hollow heated tip with a vacuum pump desoldering tool. It was pretty good, but when it died I bought the Metcal.