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How to protect PVC pipe when soldering near it?

18K views 8 replies 6 participants last post by  biggles 
#1 ·
I need to replace some copper fittings that are only about 3 inches below and slightly to the side of a PVC drain pipe. How can I protect the PVC pipe so it doesn't start melting when I solder that close to it? I tried an Oatey flame protector cloth, but it started to melt the PVC where the cloth touched the PVC pipe.

Maybe the best option is to cut out the PVC pipe and replace it when I'm done soldering, but I'd prefer not to do that if I don't have to (it's in a tight spot so I'd have to use a cable saw, which I've heard doesn't cut real even).

I was wondering if a wet rag wrapped around the PVC pipe would help at all? Or if I ran cold water from a sink through that drain pipe while I was soldering near it, would that keep the pipe cool enough to not melt? You know how copper pipe doesn't get hot enough when soldering when there's water in the pipe? Was wondering if having a constant flow of cold water going through the PVC pipe would keep it cool enough?

Any suggestions are welcomed!
 
#2 ·
You are on the right track----wrap it in a dripping wet rag then place a steel plate in front of it--

I have a number of steel electric box covers that I keep handy for that purpose---they have handy 'ears' to hold a screw or bit of wire.
 
#4 ·
pvc and cpvc have various slip-couplings and so forth which might be useful to remove/replace.

I'd go to the hardware store and look at the options available. . . I wouldn't try to solder with the pipe there - even with protection in place it might weaken it and cause a problem and then what? you'll still be dealing with the same issue - just at a later time.
 
#7 · (Edited)
cut back on the flame don't need to go in with an afterburner going...place the torch shank against the PVC:eek: and let the flame just roll over the fitting be clean and solder paste.if you doing an elbow just bearly hit the bend DON'T move the torch the heat will cover the copper without moving it......if the shank is touching that PVC the heat will go away from it... piece of sheet rock or 1/2 plywood sprayed with water slipped between them is another trick.check this video out see how this guy goes right at the fitting not concerned with whats behind it... and the torch is blasting go softer on the flame...see when he does the elbow cut back the flame and just hit the bend about a 1" away without moving the torch hook the solder 360 around the joint without moving it...pull the torch back to control the melting solder and if you go to flux it after just let the flux drip onto it don't brush hot solder.... http://www.youtube.com/watch?v=WncG1NBEKQk
 
#8 ·
Good advice above on how to handle the torch. I'm using propane ... it I soften/shorten the flame, will it still get the fitting hot enough to melt the solder? Before when I was using the flame protector cloth, my flame was touching the cloth at times, and then where the cloth touched the PVC, it started slightly melting the PVC. So if I can dial back the flame, and still get the fitting hot enough, that might be the trick.

Thanks for the tips, everyone!
 
#9 · (Edited)
the combo of the size of the flame and how close you are to the copper is forgiving....keep the flame as i said 1" away closer to get the first heat in there then back it off....the smaller the fitting the quicker it heats up and needs testing with the solder wipe and wipe...then once it melts go around 360 without moving the torch then to the other connection.once one connect takes the solder again back the torch off and wipe it(the second connection)2 Xs around your good.drip some flux onto the joints dont wipe ...let it cool and then wet an old rag and wipe it down....nice and shinny :thumbsup: map gas or acytlene do about 500F just be clean with flux...pull out a lenght 6" of solder off the roll grab it with a piece of sandcloth or emory pad then dip it in the solder....you'll flow real easy with minimal heat...
 
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