Solder choice ?

[Txflycaster]

I am about to start a half stock smoothbore build similar to a single barrel mortimer. With this having an under rib what solder is preferred?

 

[Wildrangeringreen]

Since the under rib really doesn't take any recoil force (just the slight movement of the ramrod upon firing) , You don't have to be overly particular. I use common (affordable, easy to work with) 400-460'F melting plumbing silver-tin or tin-antimony (Oatey General Purpose 95/5 Lead-Free Acid Core Solder works well) solder for everything but Sole-ing the frizzen, for that I use " Bridgit(Harris) Lead Free High Strength Nickel-Bearing Solder" (since it takes a very sharp whack on a focused area every time you fire the gun). It melts at 630'F, I essentially temper the glass-hard spring-steel at the same time I attach it; I tin the parts, wire them together, and put them in the oven at 550'F until they are up to temp, then remove them from the oven and raise it to the flow-point with a torch. By the time the part cools, the battery surface is just the right hardness to throw great sparks, but not be brittle. On a rifle that I know is going to be primarily shot with very heavy loads, I will use the Nickel solder for the barrel tenons, but I'm really not sure it's necessary.

So long as you have cleaned the parts properly and tinned them (ample flux), and have a large enough bearing surface to form the joint, the solder doesn't need to be that strong for most applications.

Permanent marker makes a good resist for solder, and reduces your clean-up time.

 

[dave_person]

Hi,
A low temperature silver bearing solder like Stay Bright or Brownells Hi Force 44 is plenty. They flow at about 465 degrees. Even standard plumber's solder is fine.

dave

 

[Red Owl]

Maybe others can comment but tinning the parts is the way to go. On some ribs when it cools, it might bend as the metal contracts.

 

[user 34300]

Yes, it is very important to tin the rib and barrel first. I tin them with acid flux paste and a steel wool ball. I work my way down the barrel and rib. I do not try to heat them all at once. Once cool enough I wash the flux off and replace it with liquid rosin flux. The rib is clamped in to place. I then heat both and add a little solder to fill any gaps completely. I use lead tin solder. I work my way along. There is no need to heat it all at once.

 

[Red Owl]

You can also have everything upside down and you will see the rib slightly move and settle in place as soon as the heat is sufficient.