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SSS
11-23-2004, 02:31 AM
Have never built a header, but doesn't look like it would be too bad. The question... could a header be brazed rather than welded? Don't know how hot the gasses are coming out of the exhaust ports of a TR7 but have seen cast iron exhaust manifolds brazed before when cracked and they seemed to work ok. I have a lot more confidence in my brazing than welding at this point in my old age: hence the question. Besides, if I got an angle wrong when fabricating I could just unglue it with the torch and start over. Anyone know if brazing it up rather than welding works?

waltesefalcon
11-23-2004, 03:40 AM
I have always welded mine up but I think brass would be able to withstand the temps of a header without coming unglued. I say give it a try and see how it works. If it comes apart weld it up.

piman
11-23-2004, 05:08 AM
Hello SSS,
I read, along time ago, that you should not braze exhaust manifolds, but the reason escapes me. What sort of welding equipment are you using, oxy\acetylene? I stick welded my flanges to the primaries but gas welded all the rest.

Alec

SSS
11-23-2004, 12:22 PM
I have oxy/acetylene and an old miller buzz box. Hmmm... saw where one of the importers had a little copy of the miller wire feed for a couple hundred. Maybe I'll drop a hint or two with lovely spouse and see what Christmas brings. Have a '53 Ferguson tractor that's suppose to be getting a little love this winter too. Might be time to switch projects for a bit.

TRTEL
11-25-2004, 12:27 PM
The usual problem with brazing is the different expansion characteristics of the two alloys. Eventually a crack will start along the contact on the less ductile metal. Depending on the wall thickness, I've gotten some fairly good (not necessarily pretty but serviceable) results using a old (read cheap) two speed and power setting Sears wire welder using flux core (no inert gas) wire. Always tack first in a couple of spots, measure, and if it lines up okay, go for it. And don't try to weld it all at once, keep dousing or spraying it with water. Good luck.

waltesefalcon
11-25-2004, 01:55 PM
Am I the only guy who actually uses a stick anymore for welding? Seems everyone has gone over to migs and tigs, I do admit I have been known to use my torch and some rod if I am working on something too thin for the arc welder.

Bugeye58
11-25-2004, 02:31 PM
Walter, I have to admit that I put my stick welder in storage years ago. I just never seem to need it anymore. I still gas weld occasionally, but mostly use the Mig. But, I rarely weld anything heavier than about 1/8 inch. Maybe I should drag the old stick out and see if I can still remember how!
And, I always Tig headers and exhaust systems. Makes for a smoother interior surface.
Jeff