Soldering Copper In The Field

Sheet Metal Fabrication techniques, questions and help. "Tricks of the Trade"

Moderators: Harold_V, GlennW

Post Reply

Soldering Copper In The Field

Post by TomBrooklyn » Wed Nov 12, 2003 6:55 pm

What are some techniques for soldering copper in the field where one has to solder vertically such as along some parts of copper gutters or roof flashings. It is hard to solder vertically.



Re: Soldering Copper In The Field

Post by gmacoffline » Thu Nov 13, 2003 10:53 am

you need to find a good tin-knocker or roofer that has done this. old copper downspouts sometimes had to be repaired and soldered like this. typically it is(was) done with irons and not torches so the problem of too much heat was seldom there. theoretically, if you use a small but hot enough heat source you should be able to heat the local area quickly and if you move fast enough and use little enough heat, the surrounding copper will keep on cooling the soldered spot so you can move along the joint and the solder will not all run out. proper joint prep and heat control technique are critical to getting this to happen. you may have to do a spot and then move down a few inches, do another, then go back up and fill in the area between after it cools some if the heat cannot be drawn away fast enough. restoration roofers do this all the time in soldering copper roof joints but most of those are not purely vertical.

User avatar
Posts: 393
Joined: Wed Jan 08, 2003 2:00 pm
Location: Massachusetts

Re: Soldering Copper In The Field

Post by Rolly » Thu Nov 13, 2003 12:08 pm

You need the old time five pound copper Iron that you heat up with a torch. Clean a flux the joint and hold the iron on it add the solder, and move up the joint.

Posts: 275
Joined: Thu Jan 02, 2003 10:47 am
Location: Atlanta, GA

Re: Soldering Copper In The Field

Post by Matt_Isserstedt » Sat Nov 15, 2003 10:23 am

The right solder alloy also helps out.

My personal favorite is Stay-Brite 8 by JW Harris. Note that there is also a Stay Brite by the same manufacturer.

The difference lies in metallurgy of the solder but is played out like this: The plain Stay-Brite has a solidus and liquidus temperature exactly equal, so "poof" the solid immediately wicks and runs like liquid when the appropriate temperature has been reached.

The Stay-Brite #8 has the solidus and liquidus temperatures offset by I think around 100 deg F, so the solder becomes kind of a half-solid that will stay in its place for a little bit. I know I'm at that when I can wipe a thin line of solder out on the copper exactly equal to the diameter of the solder. It is bonded to the copper but won't go anywhere unless I keep the heat on it and then it will flow and wick into the joint.

The unspoken and unquantified part of this is expert torch play to keep the heat "just right". And believe me I'm no expert!!! It takes experience to know when to hold the flame where and then how fast to wave it in and out of the area being heated. You'll develop the knack as a job progresses or if you do this regularly which I don't.

Good luck, I hope this helped.

PS: The website for Stay-Brite is here:
The beauty of entropy is that it is self-maintaining...

Post Reply