A question for all you soldering experts

[skyjive]

If I have a some copper fittings soldered together, and I melt the solder and pull them apart, can I solder them together again in a different way and use them safely as if they were being soldered for the first time?

[colty-bear]

try just melting the old wire then go over it again

[mark.f]

Not really.

Unless you sand all the surfaces back to bare metal, and at the same time don't remove too much material to where the clearances widen enough to inhibit the capillary action while soldering.

When I muck up a joint, I just rebuy the parts. It's not worth the work and uneasiness.

[UKSGC]

Mark thats not true at all. Heat it until it parts then simply rub the old solder down enough to get the fittings back on, reflux and go again.
I dont wish to wet anyone bonfire but I have been soldering for about 25 years.

[mark.f]

Wouldn't metling the old solder off (leaving the parts 'tinned') be better than simply sanding them down a bit?

Not arguing, just wondering.

[jrrdw]

Mark thats not true at all. Heat it until it parts then simply rub the old solder down enough to get the fittings back on, reflux and go again.
I dont wish to wet anyone bonfire but I have been soldering for about 25 years.

Important keyword highlighted in red.

[Technician1002]

Mark thats not true at all. Heat it until it parts then simply rub the old solder down enough to get the fittings back on, reflux and go again.
I dont wish to wet anyone bonfire but I have been soldering for about 25 years.

Important keyword highlighted in red.

I agree, Flux is required to crust and float off oxidized solder. I have re-used copper parts with no issues.

Instead of sanding the parts to remove excess amounts of the old solder, just heat the solder to the flowing point and quickly wipe it off with a damp rag. This removes the excess solder and the oxidized solder leaving a nice shiny tinned surface. Flux, assemble and solder. Use a cotton rag, not anything synthetic that will melt.

[cdheller]

for what its worth

although you have to heat both parts ftg and pipe it helps to throw a little more heat on the pipe .

smacking or knocking off the fitting in a strait line is usually a lot less work than pulling apart.

keep an eye on your heat it's way too easy to make every thing soft.

a flux brush works good to swipe the excess solder from the inside of the fitting ,outside of pipe too.

a dry rag works better than a wet rag in a couple of ways ..more time to get all solder off before solder hardens ,wicks some also