brazing

[hill.josh]

I am pretty much new to brazing. does anyone have any tips on doing it? checked out all the blueprints but wanted to get a few pointers.

[ThomasPowers]

This is brazing in the forge? My tips: start with the pieces as clean as possible, and if possible mechanically held together, flux with borax, heat slowly and evenly until a O-A brazing rod will melt. For steel you can also braze with copper wire or the famous penny weld with a pre 1984 penny, (a copper alloy rather than more recent copper plated zinc).

Let cool without moving it if possible.

Boil it in water to help dissolve the borax flux.

[CurlyGeorge]

OK Thomas. I have absolutely NO EXPERIENCE in brazing, with the forge. I have had guys tell me to use an O-A brazing rod and also had some tell me to mix brass filings with the borax and spread this on the joint. Which one works better? I have a small cast iron case that I'd like to try brazing back together. Thanks.

[ThomasPowers]

The forge allows you to heat a piece fairly evenly and get a slow cool down---why I like it.

Some folks go hybrid and do the pre/post heat with the forge and the brazing with a torch.

My advice is that if you don't have any experience---learn on something(s) you don't care a lot about!

[Finnr]

Forge brazing isn't all that hard. It's another thing that takes practice. As Thomas said practice on something you aren't all that fussy about.
Finnr

[ThomasPowers]

The biggest issue I had was with brazing was with charcoal; my fuel pile would burn down fast and the pieces would shift WRT each other just about the time they were getting to the proper temp...arghhhhh

[Jose Gomez]

The key to brazing is to get the parts to be joined as clean as possible, take the extra time to make sure that all joints are as tight as possible, and ensure that the parts will not slip, shift, or be bumped out of place during brazing. Once you have made it this far heat the piece gently with an O/A torch, while at the same time heating the filler metal that you are using. for torch brazing I prefer LFBFC (Low Fuming Brass Flux Covered). Which is just like it sounds, a brass rod with a thin flux coating (meaning that no additional fluxing is necessary). Heat the base metal evenly keeping the filler metal near the flame. As the base metal approaches dark cherry red melt a small droplet of brass off of the filler rod allowing it to rest on the heated base metal as you continue to heat it. When you see the droplet of brass flow into the base metal you have reached the appropriate heat, and can apply the filler metal and begin traveling along the joint. You want to keep the heat as even and as low as possible to prevent the over heating of the brass (800 degrees F). When brass is heated in excess of 800 degrees the zinc that is contained in it is burned off and can have the same effects as welding on galvanized materials.

Here are some pics of a name plate that I recently made out of a 3/16 inch thick plate, letters made of 3/16 welding rod, and a ton of braze. The letters were arranged on the plate, tack welded in place, and then I applied a layer of brass over everything. once the brass cooled I ground it flat to expose the steel letters encased in the brass,polished the face, trimmed it with twisted 1/8 in welding rod, and called it done.

[Frosty]

Very nice Jose.

A variation on the theme we did in high school was to use lettering stamps to strike the name, etc. then braze over them and grind to bare steel. It leaves brass letters on steel.

Funny, I never thought to do the reverse.

Frosty