cleaning old solder

foghat35 · Mar 13, 2007

The stub out for a stop valve I'm replacing is completely covered with solder. Blobs of solder everywhere for the full 3" of pipe. I'm putting on a compression valve so I have to get all this solder off. I plan on heating and wiping with a rag. Is there anything else you guys do to clean the pipe in situations like this?

Coz · Mar 13, 2007

heat it up, wipe with rag then you could hit it with some sand cloth.

Sponsor · 2022-01-29T12:20:58-0800

Randyj · Mar 13, 2007

what coz said...heat up again and wipe with wet rag usually gets it really clean.

hj · Mar 13, 2007

copper

A wet rag will congeal the solder immediately. Use a dry rag after the solder becomes molten. No need to sand it if you wipe it properly.

Randyj · Mar 13, 2007

not if you've already got the solder wiped off with dry rag......been there done that, got the t-shirt, got the badge, got the tennis shoes to boot....

Mikept · Feb 19, 2008

What if the solder isnt a full blob but a slight build up. Does the outside diameter of the pipe have to be perfectly round for a compression stop to work?

Rather not torch if i dont have to torch.

Mikey · Feb 20, 2008

mikept said:
Does the outside diameter of the pipe have to be perfectly round for a compression stop to work?

I'd bet no, but you have a great opportunity to experiment. I doubt you could even get the ferrule on the out-of-round piece.

Rather not torch if i dont have to torch.

That's the fun part. Use a heat shield to prevent burning the house down. I made one out of an old 29oz fruit can that I've been using for years. I just reworked a bunch of copper yesterday and quickly found that the torch is the only tool worth using to clean up the 30-year-old globs and such. Solder is tough stuff -- much too hard to sand. Once it's melted, you can either wipe it or blow it off the work.

hj · Feb 20, 2008

solder

Slight buildup or blobs, it doesn't matter. It has to be removed or the valve will not go on, much less tighten and seal properly.

Mikept · Feb 20, 2008

I think theres a clean spot between the buildup and blob

How much pipe do i need for a compression fitting?

Herk · Feb 20, 2008

If you have too much buildup, the nut will not go on. Generally, if the nut goes on, the ferrule will go on.

You need to bottom out the pipe in the socket of the stop.

Mikept · Feb 20, 2008

generally how many inches of pipe will i need to bottom it out?

Frenchie · Feb 20, 2008

Dude - just torch it, already.

Cass · Feb 21, 2008

Heat and wipe the pipe, see if the comp nut and ferrule slide on, if not sand a little till it fits, install comp nut then ferrule then valve, push valve all the way on to pipe and hold it in, place 1-2 drops of oil on threads, hold back valve with channel locks, tighten nut by hand then with anothe pair of channel locks tighten the nut, CAUTION don't under or over tighten the nut.

Mikept · Feb 21, 2008

I believe in my case i have enough lenth to cut sweat wipe and install a compression stop.
But if the stub was too short would i unsweat the stop instead of cutting it off, or would i have to open the wall and replace the stub? *just curious*

Jadnashua · Feb 21, 2008

My guess is that you need a little over 1/2" or so and probably less than 3/4" of stub sticking out of the wall to install a compression stop. Now, if you want a bezel on the wall, you need maybe 1/2" more. This could vary depending on the brand chosen. You'd have to measure to be sure, or view the specific installation instructions.

Mikept · Mar 4, 2008

Heated with my new bernzomatic ts8000 torch, Wiped the solder cut the pipe and installed new compression stops Quite easy and No Leaks!!! Not to hard to do...

Where does the compression seal form? the very end tip of the pipe or the OD of the pipe?

Im surprised that the metal seals together leak free.

When i was snaking the lav drain i checked the stops and they were broken, the hotwater didnt close and the cold dripped for a while after turning. When changing the stops i noticed the rusted through lav hanger bracket was 1/3 missing.

Mikey · Mar 4, 2008

The compression seal is formed when the ferrule is squeezed by the tightening of the compression nut. Try taking one off and you'll see...

Mikey · Mar 4, 2008

Cass said:
CAUTION don't under or over tighten the nut.

I guess it's easy to see if you've under-tightened the nut, but never thought it was possible to over-tighten it. This is another Goldilocks thing -- it has to be "just right"?

Mikept · Mar 4, 2008

Mikey said:
The compression seal is formed when the ferrule is squeezed by the tightening of the compression nut. Try taking one off and you'll see...

I know when the seal was formed, im curious about where it seals to the copper, the cut end or the sides of the tube.

hj · Mar 4, 2008

seal

It seals at both sides of the ferrule/ring to the outside of the copper. The end of the tubing just keeps it straight in the fitting or valve.

cleaning old solder

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