SOLDERING

[hortonstn]

what is the difference between soft soldering and hard soldering and which method would you use to solder underbarrel lugs on?
thank you
paul

[Acer Saccharum]

Plumbers use a low temp solder and flux. The old standby was 50/50, which was half tin and half lead. The replacement for this is 95/5, which is tin/antimony. These solders can be successfully used with an acid or rosin flux at 600 deg F.

Silver braze, or silver solder, depending on the alloy, runs from melt temps from 900 deg F to 1500 deg F, with a borax based flux. It's important to use a flux that matches the melt temp of the solder. Any welding supply place can help you with this. I would not use this for underpin lugs. Yes for a bayonette lug.

For barrel lugs, I use the 95/5, as it does not require as much heat. You do need a broad base on the lug for good adhesion and strength.  Be sure to heat the barrel evenly all the way around. A localized hot spot can bend a barrel.

Tom

[38_Cal]

Many of today's solders are tin/silver, usually from 4% to 6% silver.  These are still classed as soft solders, and a soldering iron for small pieces or a propane torch for large pieces will work well with them.  I prefer NoKorrode or similar non-acid fluxes with them, especially for repairs where you don't want to harm an existing finish.

David

[Ron Brimer]

Too much heat , you can scale inside the bbl wont be able to hit the house. Then you would have to lap it.
     Ron B

[caliber45]

Paul -- Use SWIF paste solder from Brownells. It already contains the ground metal and flux. No need to "tin," no need to worry about snips of solder wire and all the other irritants that go with traditional soldering. It's strong. Flows easily with propane heat. Never had an underlug separate. -- paulallen, tucson az