Difficulty removing components from vintage electronics

[bluzmn]

I've been working mostly on vintage amps lately; I've found that on most of them the leads of the components are not only put through the holes in the mounting tabs but are also wrapped all the way around the tabs, making them a real PITA to remove and replace. Does anyone have any tips or tricks to make this process easier?

[Chuck H]

A desoldering tool can help sometimes. Especially if you don't like molten solder blobs flinging up in random directions. If your replacing components you can often just stick the new component in place, then snip the old one out. If your replacing several components and they're all wrapped in tight you can lift the board (usually enough without the need to remove wire leads) and snip out the components, then melt fresh solder into the eyelet and let the old junk drop out the bottom. Then suck out the eyelet again if needed. Sometimes I just get agressive and melt the solder and rip the end up. I use a narrow nose plier to grab the component lead near the joint and just twist like I'm trying to wrap the lead around the closed plier end. If you want to preserve what you pull, sometimes the only option is to lift the board AND remove the solder so you can work the lead with the least amount of stress. If you find that you need to take much time with the solder melted you can clip a plier to the lead your working on to act as a heat sink and help protect the component body. I use a pair of hemostats. But when unable to find them I've also used the same pair of narrow nose pliers with a rubber band across the handles for tension. A couple of other things that have helped are a nut pick (an actual tool made to pick the bits out of cracked pecans and walnuts) and a soldering iron tip that I have curved to a right angle (the bomb).

HTH

[Enzo]

I didn't read the question as eyelets, I envisioned him asking about things like tube socket pins or termnial strips.

A pointy tool plus the iron, and you can sometimes get under the end of the component lead and wedge it outwards. Once started, it gets easier to unwrap.

Sometimes getting it half way is close enough. If I can expose a bit of a loop in the lead wire, I can snip it in half with my dikes. Then i just have two pieces of wire, no unbending.

SOmetimes it is tight, too tight. I have small dikes, along with the large ones that cut AC cords in half. The small ones are for snipping component leads and such. But I have some small ones that will work in close quarters. Plus some flush cutters. So sometimes I can nibble off the wire lead as it curves around the terminal. Once the little knot of wire is cut in half, it is easier to worry it off.

[bluzmn]

You're correct, Enzo, I'm talking about tube socket pins and terminal strips; true point-to-point wiring. I'm sorry, but what are "dikes" and "flush cutters"?

[rf7]

Dikes with an i are wire cutters. Flush cutters are wire cutters that are ground flush to the apex of the cutting edge on one side of the jaws.

[Enzo]

Sorry.

Dikes is slang for diagonal cutters - your basic wire cutters.

If you look at your dikes, you will see the cutting edges are bevelled back from both sides, so if you lay the cutters flat on the table around a vertical wire, and cut, they will nip off the wire a little bit above the flat surface due to the bevel.

Flush cutters are darn similar except the bevel is all on one side. You can lay the cutters on the table and the cutting edge will be flush against the table.

I use flush cutter to snip off the legs from an IC body, right flush with the body.

"FLush cutter" todays seeems more and more to refer to those cheap stamped cutters, but I prefer some nice quality ones that are real pliers, not two flat pieces riveted together.

FLush cutters will get you that last extra half a millimeter closer to the work.

[Tom Phillips]

In addition to the methods Enzo described I use a tool known as a fork & hook soldering aid. I have a couple of different sizes. The closest photo I could find is attached. After sucking the solder out of the joint I reheat the joint, slide the fork end of the tool over the end of the wire and then a twist of the tool unwraps the wire.

[tedmich]

the all in one solder sucker/iron units really help especially if you are using a hook with your "free" hand!



wire wrap, now thats a pain...

[JHow]

In addition to the methods Enzo described I use a tool known as a fork & hook soldering aid. I have a couple of different sizes. The closest photo I could find is attached. After sucking the solder out of the joint I reheat the joint, slide the fork end of the tool over the end of the wire and then a twist of the tool unwraps the wire.

Dittos. I used to play a lot with 1940s Philcos and they wrapped everything like crazy. I have even see working radios with unsoldered lugs that still worked because they were wrapped tight.

[Enzo]

As is the proper method. The solder is not there to provide mechanical strength, it is there to ensure good electrical contact.

[rjb]

As is the proper method. The solder is not there to provide mechanical strength, it is there to ensure good electrical contact.

I would never disagree with you, but NASA might: http://www.protostack.com/download/N...0Soldering.pdf

"Slide the wire off the terminal. Using wire cutters, flush cut the bent wire so that it will only make contact with the terminal for 180 degrees minimum (1/2 turn) to 270 degrees maximum (3/4 turn).

26 AWG and smaller wire shall be 180 degrees minimum (1/2 turn) but less than one full turn 360 degrees maximum (1 turn)."

But, of course, radios and guitar amps need to meet much more stringent demands than NASA might require!

-rb

[Mark Hammer]

Heavier gauge solder wick is also helpful. I've been using solder suckers for decades, but I find they often can't get close enough to the joint to provide enough suction. And in the case of terminal strips with heavier gauge leads wrapped around them, the amount of heat you need to apply to flow the solder can damage the teflon ends of the solder sucker. Solder wick lets capillary action do the heavy lifting, after a quick once-over with a solder sucker has taken the first 60% of the solder away.

I recommend using your pliers to stretch the solder wick out sideways and create larger surface area. Then, dab some liquid flux on the solder wick with a cotton-tipped applicator/swab to "supercharge" the wick.

I stayed away from the stuff for ages, but am now a convert. Removing all that solder "webbing" not only provides let material to adhere the cvomponent leads to the solder tabs, but also lets you see the damn leads clearly so you can tell where to grip it and unwind it from.

[rjb]

I've been using solder suckers for decades, but I find they often can't get close enough to the joint to provide enough suction. And in the case of terminal strips with heavier gauge leads wrapped around them, the amount of heat you need to apply to flow the solder can damage the teflon ends of the solder sucker.

I find a bulb type solder extractor (like the lower pic in tedmich's post) easier to use and more effective than those plunge-type solder suckers. Got one for cheap a bunch of years ago at Radio Shack, haven't used the Solda-Pullit since.

-rb

[Enzo]

I hate bulbs, and much prefer the cock and shoot things Everyone has their favorites. On the other hand, if I have a recalcitrant part, I might prefer to leave the pool of molten solder when extracting the lead - it helps conduct heat into the joint. ANd perhaps beyond the scope of this thread, I use a desoldering station in preference to the manual suckers.

And I haven;t picked up any braid in decades. I don;t like braid at all.


RJB, it wouldn;t be the first time experts had different views from mine, ask my wife, she's convinced I am always wrong. But I am not sure how NASA was disagreeing with me. They require the wire be wrapped at least 180 degree around a post - a U-turn around the post. and preferably 270 degrees - around the post and crossing itself. That is the sound mechanical joint. The solder then keeps it from coming loose, but also and importantly makes the electrical contact reliable and secure.

[rjb]

But I am not sure how NASA was disagreeing with me. They require the wire be wrapped at least 180 degree around a post - a U-turn around the post. and preferably 270 degrees - around the post and crossing itself. That is the sound mechanical joint.

Somehow that's not what I envisioned when JHow said "I used to play a lot with 1940s Philcos and they wrapped everything like crazy."
NASA says to wrap *no more* than 3/4 turn around the post; 2 or 3 times around is way too much.
In other words, make a sound mechanical joint that can still be undone for repair.
I do subscribe to the credo that "solder is not glue".
So, it looks like NASA, Enzo, and rjb all agree. I can't speak for Enzo's wife.

-rb