Brazing

[flyguy]

Speaking of "brazing," I ran across an interesting section in a welding book a while back. Was about making "tubular" frames for racing cars. They were brazing them together, rather than welding. This is brazing in the sense of having a VERY tight fit over a larger area with very thin brazing material in between. Brazing as opposed to brass welding where a void is filled with molten rod material. The author made the point as no one would build a car using brass welding.

Interesting point now that I reflect on the salt bath brazing (magnesium if I remember correctly) of RF waveguide type assemblies that was done one place I worked. Another was electron and Traveling wave tube assemblies using hydrogen-filled ovens. Thin material between tight surfaces. Yep, brazing, not welding.
DC

[astjp2]

Re: Brazing

Where ever you got that information, it is wrong. It sounds like frictions stir welding is what they are talking about. You dont weld steel with brass rod, to weld, you must melt the base metal for a true weld and the brass will burn before it gets that hot. Tim

[bashibazouk]

Re: Brazing

Some more Kent White propaganda can be found here, including definitions of soldering and brazing. As long as you're not melting the base metal, regardless of the method of heating, you're still soldering or brazing. Welding always involves melting the base metal, whether it is with an arc, gas flame, friction, or PFM.

Shouldn't this thread be somewhere else? Maybe in the technical discussion section? Just a thought. Hate to be the thread police. Oh, wait. I'll fix it:



Picture of a tree frog that stowed away on my flight out of Natchez, MS this summer. It was taken in a Taylorcraft and has nothing to do with welding or soldering.

[Guest]

Re: Brazing

It might, I bet froggy was wishing he was welded or brazed to that window!

[mulwyk]

Re: Brazing

I don't know about racecars, but the method flyguy describes is used to make high quality bicycle frames. They use little cast (?) fittings at the joints. The tubes are inserted into the cast fittings and then brazed in place. The bicycle guys claim their "brazed" frames are stronger and lighter than welded frames. They are also quite expensive.

[flyguy]

Re: Brazing

Yep Bob, that is the process the guy was talking about.

I was hesitant to use the term brass welding, because obviously if you don't melt the parent metal it isn't welding as Tim points out. The guy that used that term was trying to differentiate between what is actually thin layer brazing, as I described, and filling in a larger void with bronze rod. He didn't have a word for it, and I don't either. They are both brazing, but the strength of the joint is quite different.

As for the salt bath and oven processes they are indeed BRAZING, in it's most basic sense, (or any other sense.) The term the engineers use for it is dip-brazing.

I spent more time calibrating the temperature spread inside those baths and ovens, in my younger days, than I care to reflect on, and I assure you I know what I am talking about.

DC