brazing a frame

hi,

i'm starting to research my first build. i'd like to do most/all of the fabrication myself. when it comes to the frame my brazing skills are far stronger then my welding chops. are there any folks, resources that deal with brazing frames and bodies?

Done properly, Brazing is plenty strong.
BUT ... Brazing is easy to do poorly, too much heat kills the strength.

Brazing is still used on production Formula car chassis in England.
Also used on light aircraft frames.

Some guys have used Brazing to build "Locost" inspired chassis.
Locostusa.com

Brazing is not popular for bodywork, because dissimilar metals can lead to corrosion.

Welding with acytelene is better than Brazing per say. Just because Brazing is done with brass rod. If you are super good at acytelene welding it is a fine conection. Better for lighter weight materials. The frame work might be questionable, Although it could be done.

I weld for a livin. I wouldnt. Practice at your welding a lil more. If you can braze or tig than mig or stick should come in easy far ya.

i can braze pretty well. i have the heat control to do it right and i think a good braze is more then adiquate and stronger then a lot of welds (stir the pot). i'm not worried about the stregnth.

i'll look into the locost stuff.

are there any builders who chose to braze that are on this site?

Well if this is your first or hundredth build - - -You should be worried about the strength!
I've been welding for over 40 yrs. - motorcycle frames/gas tanks - car frames/bodies and have even built one off bicycle frames. I've used silicon bronze, sliver braze,brass braze, O/A welding and tig & mig welding. As far as strength goes for a frame, your stick,mig & tig would be your best bet - Braze and O/A welding would be good for body work. But with silicon bronze and brass if your heat is just the slightest bit hot - your strength and flexability has gone out the window, it becomes brittle and can not withstand any stress or vibration. It is best to use some form of filler material that is close to the parent material - ie: steel for steel. - not only will welding heat be a strength factor,but also your ambient temps will factor in as far as expansion and contraction between to dissimilar metals - ie: steel and brass. Plus brass is only a filler rod,not a welding rod, where the parent material and rod are similar and you have penetration.The best thing to do would be to check with your local welding shop or steel distributer for the tensil and shear strength of your parent material and the brass rod.

Lightning said:

Well if this is your first or hundredth build - - -You should be worried about the strength!
.

Click to expand...

maybe i should rephrase.

i know that brass brazing will produce a frame that is strong enough. with tight miters and good heat control everything will be fine. i'm not questioning the stregnth of brazing.

the tool is only as good as the operator. just cuz a guy (not you) has a mig or stick set up does not mean he producing welds stronger then another operator's brazed joint. i can make bird **** welds all day long with a mig but it doesnt mean they are strong.

if brazing is not your prefered method, thats cool.

I don't think that is it, here we have several welders who are saying welding steel together with brass is not a strong weld. You should be questioning the strength of brazing, when we are talking about a car frame. Go ahead on brazing the body. I have seen old car bodies that have held up pretty well, but re-think the brazing of the frame.

I think you will fight cracks after a time.

I can braze pretty well too but wouldn't trust a frame make that way. Doing 70 or 80 mph and hitting a big bump or hole is not my idea of fun. Just my .02.

Beercan

Well - if you insist on brazing your frame together - by all means - do us the courtesy of letting us now when you are running and on the streets so we can stay clear. You post a question about brazing a frame together and then you dismiss all of the answers that tell you not to - Why even bother asking the question?

I would not braze frame joints. Thats like suicide going down the road. Either stick,Tig or Mig for the frame joints.

Brazing if you like that type of welding should be done on light work such as sheetmetal and body panels. Although its even a lost art for that with all the newer tech that we have today.

By all means,Listen to all the answers that you have gotten here. It may save yours and someone else from being seriously injured.

monkey wrench said:

hi,

i'm starting to research my first build. i'd like to do most/all of the fabrication myself. when it comes to the frame my brazing skills are far stronger then my welding chops. are there any folks, resources that deal with brazing frames and bodies?

Click to expand...

I guess you don't value your's or other's life.
Your NUTS !!!!!!!!!!!!!!!!

ok.

my post was not a question of whether brazing was a good choice. i ask if there were resources out there for folks looking to braze a frame.

there are thousands of motorcycle, airplane and car frames that are brazed together. it works.

i will take eveyone's advice and continue to research.

thanks

I will put my tig up against your braze any day. Not to be jumpy or anything just wanted to state the obvious. Brazing was designed for non similar metal fusing. Good luck with your brazing and I know it will turn out fine for ya.

monkey wrench said:

there are thousands of motorcycle, airplane and car frames that are brazed together. it works.

Click to expand...

I could see a show bike with a brazed frame but I doubt it would ever hold up to any serious street time much less a car frame on the streets. I wish you all the best with that as you seem to have your mind set on doing it.

Lightning said:

Well - if you insist on brazing your frame together - by all means - do us the courtesy of letting us now when you are running and on the streets so we can stay clear.

Click to expand...

What he said!

And sorry, don't mean to throw a "monkey wrench" into your plans!

Beercan

Not to be a bandwagon jumper, but these guys know what they're talking about. My welding is improving, have a 220 stick and a miller 125c, but wasn't confident enough to weld the frame on my 1st build. I ran a D-50 chassis (yeah, I know) and would suggest finding a donor chassis and more or less plug and play the essentials (steering/brakes) from the donor to the new cab/cowl whatever. That saves a ton of time, and with a modern chassis adaptation, you get the ride quality and engineering that came from the donor.

All of your old Harleys,Indians and other brands of motorcycles were furnace brazed, where the braze went all around the tube where it slipped into another tube. Most of your modern day braze jobs on race car frames,bicycles, ect: are done in this manner - alot stronger than just a fillet,butt joint or lap joint and it is done with a silver braze[lots of $$$$] or a braze made up of certain percentages of different combinations of alloys for tensil strength and durabilty under stress and vibration.

I'm an Collision Tech. Have been for many years. Here in Ontarion Canada Brazing a frame is illegal, and for good reason in my oppinion.

i respect your opinions and i will concider tig as an option. but i believe you are underestimating the stregnth of brazed joints. i understand that if done properly they are stronger then mild steel, 50,000+ psi. in my destruction tests the joint does not fail, its the steel that stretches and the joint holds. additionaly the lower heat used and the fact that the parent material (steel) does not melt you have a lower occurance oxidation and impurities entering the weld and causing future cracks. which is the reason many folks purge with argon.

o my god dude ,,freakin listen..