Advice on joining larger pieces of brass

[Rex Walters]

Ah, I think I see now. You are making the fence out of two diameters of brass, both larger diameter than the drill rod you’ll use to hold the scriber. The threaded hole to secure the drill rod will go through the side of the smaller diameter brass.

If I go the silver solder/brazing route, would I just sit them flush, or cut a socket for the thinner brass to seat in?

Soft solder (plumber’s solder, usually and preferably, imo, a lead alloy) has very weak peel strength. You will want some sort of shoulder or joint to provide mechanical strength.

A through hole the size of the smaller piece would work, but it’s a good chance to try boring a flat-bottomed hole on your lathe. You’d only see the solder on the inside of the joint that way.

Soft soldering is also brazing, by the way. Brazing just means melting a dissimilar metal to hold things together, as opposed to welding which actually melts the base metal parts.

Clean the parts well before soldering. The solder will tend to follow the flux, so apply it neatly and wipe away excess before heating (especially true with silver solder). Ideally, you want it to wick into the hole and nowhere else, leaving just a small amount at the interface visible.

I’d still go the peened square tenon route myself, though. Done well, it will look like a single piece of metal. Break out those files!

 

[homebrewed]

Awhile back I wanted to solder a brass bushing deep inside a length of 1/2" copper pipe. It was for a home-made water spinner/sprinkler and the bushing was used to support the spinning portion of the sprinkler. To do that, I cut a groove in the bushing that was deep and wide enough to wrap some flux-core solder around it without being proud of the surface. I cleaned the ID of the copper pipe, inserted the bushing+solder and heated the pipe with my propane torch. The solder melted and wicked into the space between the bushing and pipe. Dabbing some extra flux on that portion of pipe would help the solder wet the copper/brass but it worked well enough for me without doing that.

If you do something similar, you likely will have a joint with no obvious solder showing on the outside.