# Desoldering



## TNTTNT (Nov 2, 2008)

I hope I don't offend by asking a very basic question. Just forgot to put the body of an RCA plug on to the cable I was making.

I thought I would try to desolder and start again. I placed the tip on the solder and it didn't melt. I held for quite a while, and still solid. I turned the temperature up bit by bit to 900f, and the plastic ring holding the centre signal pin melted. The solder was still not melted.

Is there a basic technique I have missed to desolder a RCA plug? My iron is a 60w iron with temperature control:-

http://www.maplin.co.uk/Module.aspx?ModuleNo=218050

I have only used the tip a couple of times. It is a fine point one, and the tip is now black, with no silver tip. It came with the iron.


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## sparky77 (Feb 22, 2008)

use a fine file or emry cloth and clean the tip till it shines, and have a damp cellulose sponge handy, when you heat the iron, when the iron is hot, wipe the tip on the sponge so it's nice and shiny, then put a drop of fresh solder on the tip so it only sags a slight bit. Then touch the tip to the point you want to melt again, and it should work fine. Also doesn't hurt to have one of these.


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## TNTTNT (Nov 2, 2008)

Great thanks. I'll give this ago. It is 1.09am here and I was looking at cleaner powders, when I got your reply. Some of these claim to clean and tin the tip.

I have a solder pump, but it is rubbish. The end is very large and it is hard to get to the solder. Your link looks great. Really solid and fine tipped.

I am surprised that the solder didn't melt. When I put some fresh solder, it melted quickly. The old bit I tried to desolder was like granite stone - didn't budge.

I know it is easily done, but I still feel like a dumb for leaving the RCA body off the cable.


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## lcaillo (May 2, 2006)

Do not use emery cloth on a tip. You will remove the plating and it will oxidize continuously and never remain tinned. Use steel wool or a wet sponge or even a paper towel.


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## sparky77 (Feb 22, 2008)

steel wool would do exactly the same thing as emery cloth, but since you've already used it to solder, theres not too much to worry about as long as you only wipe off the dark stuff. The best is heat up the iron, and wipe it on a damp sponge, and the ultra cheap cellulose sponges work the best, as the plastic based sponges do tend to melt and stick to the tip of the soldering iron. Having a little bit of freshly melted solder on the tip does help a lot in getting the premelted solder to melt again.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Interesting, I've never had to use steel wool or emery cloth. Just clean the tip with the usual wet cellulose sponge, press it to the soldered terminal for a second and add a dab of solder. That's usually all it takes. Something about the resin helps the old solder melt; never understood why.

Here's a tip for desoldering RCAs. Plug it into a 1/4"-RCA adapter. That way if the plastic insulator gets a little soft, the adapter will hold everything steady until it cools off, and you won't ruin your connector.










Regards,
Wayne


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## TNTTNT (Nov 2, 2008)

Using the 1/4" adaptor is genius. I need to go to the electrical store today, so I'll add to list.

I thought that the solder was suppose to coat the tip - is this right? On the blackened tip I find that the solder rolls into balls and and runs off. I'll try the abrasive suggestions.

On a twist to RCA soldering, do the quality of RCA plugs matter. I read Wayne's guide, and will avoid the plastic cheapies. I want to get different plugs this time for the next job. I mean I have a choice between: -

http://www.canford.co.uk/Products/43-024.aspx

and

http://www.canford.co.uk/Products/43-061.aspx

I must say I thought the latter was a quite a bit more expensive. It is for a decent hi-fi, so don't mind spending if there is a reasonable difference.


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## lcaillo (May 2, 2006)

sparky77 said:


> steel wool would do exactly the same thing as emery cloth, but since you've already used it to solder, theres not too much to worry about as long as you only wipe off the dark stuff. The best is heat up the iron, and wipe it on a damp sponge, and the ultra cheap cellulose sponges work the best, as the plastic based sponges do tend to melt and stick to the tip of the soldering iron. Having a little bit of freshly melted solder on the tip does help a lot in getting the premelted solder to melt again.


Emory cloth is far more likely to take off the plating. I have tried it, along with many other things, and after thirty years of daily soldering, I use steel wool or even better, one of those pot scrubbers that look like very coarse steel wool. The steel wool grabs the larger debris off the tip far better. YOu can also just stuff it into the holder for the iron and form it into a holder for the tip that cleans it every time you put it in the holder.

I use temperature controlled stations, so I prefer not to cool my tips with wet sponges. If you are using an iron that is not well contolled, it may be useful to cool the tip a bit to keep it from oxidizing, so a wet sponge can be very effective. I don't like that method because you have to keep wetting the sponge, and when you work with your iron all day every day, it gets to be more trouble than it is worth.

This is one of the most effective ones, and as you can see is made by Hakko, the soldering station people. You can do the same thing by picking up a pot scrubber from the grocery stor for $2.00 and stuffing it into your iron holder.
http://www.kiesub.com/prostores/servlet/Detail?no=12


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## lcaillo (May 2, 2006)

Wayne A. Pflughaupt said:


> Interesting, I've never had to use steel wool or emery cloth. Just clean the tip with the usual wet cellulose sponge, press it to the soldered terminal for a second and add a dab of solder. That's usually all it takes. Something about the resin helps the old solder melt; never understood why.
> 
> Here's a tip for desoldering RCAs. Plug it into a 1/4"-RCA adapter. That way if the plastic insulator gets a little soft, the adapter will hold everything steady until it cools off, and you won't ruin your connector.
> 
> ...


If the insulator gets hot enough to get soft, you are heating ineffectively. Usually this is because of an iron that is not holding heat enough and/or to low power. Use a larger tip or larger power iron, be sure the tip is not oxidized and is clean, and maybe use a little flux.


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## Anthony (Oct 5, 2006)

I've found that a simple solder pot and wet sponge (in the base of the iron stand) is enough to keep the tip perfectly clean. The pot is available from Radio Shack for like $4 and you just plunge the tip into it. It's basically cleaning rosin with a little bit of solder in it. Keeps the tip perfectly clean. Wipe it off when finished.

For desoldering a "wet" tip as described above is a must. This is especially true for thick wires or connectors, as they act like heat sinks. Also a desoldering plunger or braid works well for when the solder finally melts. The plunger is klunky but usually gets teh job done in one pop. The braid wicks away the solder, but sometimes it takes a couple of tries to get it all off.

Good luck.


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## Wayne A. Pflughaupt (Apr 13, 2006)

TNTTNT said:


> On a twist to RCA soldering, do the quality of RCA plugs matter. I read Wayne's guide, and will avoid the plastic cheapies. I want to get different plugs this time for the next job. I mean I have a choice between: -
> 
> http://www.canford.co.uk/Products/43-024.aspx
> 
> ...


Yeah, quite a difference in price there. Maybe you can find something in between? Personally I don’t think any RCA is worth more than $2-3 (1.35-2.07 in your currency). They’re low end connectors, no matter how much they “pretty them up.” Any chance you can find the Neutrik NYS373 somewhere? Great connector for a low price.

Electrically speaking, there really isn’t much difference between the two you linked there (if anything at all). The primary difference is build quality and ease of installation (for you that means if it’s easy or a pain in the neck to solder a cable to it!). Also, cheapie RCAs like the first one you linked usually don’t have very good cable clamps. If it’s the kind you squeeze down with pliers, it needs to be able to get fully around the cable, not just the sides (top picture, not bottom picture!)



















Regards,
Wayne


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## Anthony (Oct 5, 2006)

I second the recommendation on the Neutriks. The few times I have made RCA cables with solder ends (I usually use crimp and coax), I used Neutriks with good results. You can just feel how much more solid they grip, the strain relief is better, and they obviously gave thought to the assembly process (and making it easier).


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## Wayne A. Pflughaupt (Apr 13, 2006)

lcaillo said:


> If the insulator gets hot enough to get soft, you are heating ineffectively. Usually this is because of an iron that is not holding heat enough and/or to low power. Use a larger tip or larger power iron, be sure the tip is not oxidized and is clean, and maybe use a little flux.


Yeah, you're right - the thin pointy tip I like to use is great for fresh work because it's easy to maneuver in close quarters. I should probably switch out my tip for desoldering, but typically I'm immediately re-installing the recycled connector on another cable. Hmmm, maybe I should look into getting a second iron... :T

Regards,
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

TNTTNT said:


> Using the 1/4" adaptor is genius. I need to go to the electrical store today, so I'll add to list.


The 1/4" adapter has other uses as well! You can use it with a clothes pin to help keep the RCA still and in place while you're soldering.










Regards,
Wayne


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## lcaillo (May 2, 2006)

You should market that solder work support device. Very clever design.


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## TNTTNT (Nov 2, 2008)

The ideas suggested have been very useful. In fact I have tried most since posting. I bought some new tips and I am shocked at the difference. The tip goes through solder like butter.

There is much advice on the web given to novices on soldering, but I don't think it is stressed enough how important it is to take care of the soldering iron tip. I think these can be reduced to: -

- Keeping the tip tinned, especially before storing away
- Don't solder at too high a temperature
- Keep cleaning the tip at the sign of oxidation.

I tried the suggestions. The kitchen scourer was a good idea and worked to some extent. The cleaning flux was quite good. I bought some Henkel Cleaner

http://www.farnell.com/datasheets/108282.pdf

It fizzes away and leaves a black residue in the flux pot. It worked again to some extent.

All these suggestion have nearly retinned the old tip. There is a black area on one side, and I think this tip is past saving. At least all of this has helped me to understand iron care.

I think I have found some Neutrik RCAs which are in between the two suggested, so thanks to Wayne and the forum community.


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