Brazing or welding

[breezeblock]

going to build new wishbones for car what isbetter brazing or welding

[rcarr]

welding because its cheaper and its only thin guage metal you'll be using, brazing can become stronger than the actual metal!

[graham bahr]

yep done right brazing can be stronger due to the large contact area gained as the braze flows through the joint, but you do need a larger contact area between the two parts than with welding, also a brazed joint can be mellted and pulled apart again to make adjustments or redo it.

for very thin materials gas welding, or brazing are more suitable than mig as the intense localised heat puts a weak spot in the metal alongside the weld.

either method you will need a jig to hold the parts whilst you do it, but welding is much more likely to cause distortion if your jig isn't strong enough to resist the distortion

mig welding is by far the quickest and easest and probably allround best assuming you can do it, and if you cant dont even think about making wishbones!

[zefarelly]

what Graham said . . . another option is to tack weld in position, then seem fill with braze

as an example, radius armes on a MK1 Cortina are spot elded in position then can be brazed for additional strength, Escort shells where prepared for competition in the same way I believe.

the biggst problem with welding is not weakening the parent metal, almost impossible to check at home in your workshop, but it didn't stop COlin Chapman and hundreds of others !

[JimW]

Originally Posted by zefarelly

. . .
the biggst problem with welding is not weakening the parent metal, almost impossible to check at home in your workshop, but it didn't stop COlin Chapman and hundreds of others !

As several of their drivers found out!

Jim

[zefarelly]

look at racing push bikes . . .until very recently they've always been brazed.

very strong, and light

laser welding anyone ?

[breezeblock]

what code of filler wire should i use for 4130 tubing

[ger80]

laser beam welding is very good because you didnt warm the part as much as normal welding. but you normal need process monitoring or something like that to be sure that the quality is ok. or is it only because i am working in quality ?

[breezeblock]

funnily enough i dont have laser welding in my garage

[brickkicker]

but you normal need process monitoring or something like that to be sure that the quality is ok.

Ill get you a substantiation report if you want

[thatorangething]

If I make a steering or suspension component I have to ask myself whether I can be absolutely sure that the component I am making will never break before I embark on the job. Some time ahead, my component might put me, or a fellow competitor or road user in a box.<p> One option is to take the best advice on materials, sizes, joint clearances and processes, make your wishbone prototype and jig, make a set of wishbone pieces, and take the whole lot to a welding/brazing specialist who works on racing or aircraft components with complete confidence. He'll soon unload you if he doesn't like the look of the idea, or your workmanship though, and dont expect politeness, because he fully understands the life-and-death nature of his work!

[zefarelly]

I had a look at what one reputable suspension manufacturer did for my car (at great expense) didn't think the world of it so I went and bought my own inserts and made my own modifications in a similar fashion, but I Know my prep was thorough and my welding is strong enough. I did an hour and half of very bumpy street racing at Chimay and nothing has shown any signs of damage or movement, and that included several very heavy kerb clips sending the car up on two wheels when I got my lines wrong !!!

[knighty]

Nickel-Bronze brazing is the stuff you should be using, the rods have about 10% nickel which maket it slightly harder than normal brazing rods........this is what Vandiemen use to braze their chassis together, but interestingly all wishbones are tig welded - but the tig welds are of the best quality.........a word of advice, If your going to braze - get a gas-fluxer........the powder stuff makes the braze look horrible......... dont put a mig welder anywhere near thin-wall tubing.......its strictly tig or brazing

[zefarelly]

thats it then . . .whgen the mig gives up the ghost ( can be arranged ) I'll keep the gas bottles and get a tig welder !

[bugs]

Originally Posted by knighty

Nickel-Bronze brazing is the stuff you should be using, the rods have about 10% nickel which maket it slightly harder than normal brazing rods........this is what Vandiemen use to braze their chassis together, but interestingly all wishbones are tig welded - but the tig welds are of the best quality.........a word of advice, If your going to braze - get a gas-fluxer........the powder stuff makes the braze look horrible......... dont put a mig welder anywhere near thin-wall tubing.......its strictly tig or brazing

Hi spoke to you on the phone the other day re. gasfluxer what goggles did you use? (job to see with green lense ones) Andy B.

[Robyn Slater]

Yea,TIG welding is the way to do it.

[graham bahr]

Originally Posted by knighty

.... dont put a mig welder anywhere near thin-wall tubing.......

i suppose that depends on how thin were talking about, the thickness of the material depends on the application and we dont know what these wishbones are for

[StephenRae]

Originally Posted by graham bahr

yep done right brazing can be stronger due to the large contact area gained as the braze flows through the joint, but you do need a larger contact area between the two parts than with welding, also a brazed joint can be mellted and pulled apart again to make adjustments or redo it.

for very thin materials gas welding, or brazing are more suitable than mig as the intense localised heat puts a weak spot in the metal alongside the weld.

either method you will need a jig to hold the parts whilst you do it, but welding is much more likely to cause distortion if your jig isn't strong enough to resist the distortion

It doesn't matter how strong the jig is, the stresses induced by welding will still be there when the part is 'pinged' out....to be pedantic we should be talking about bronze welding not brazing, whch relies in the brass between the parts and does not include a filler fillet!

[phoenix]

Originally Posted by knighty

dont put a mig welder anywhere near thin-wall tubing.......its strictly tig or brazing

How thin is thin? What wall thickness is the minimum for MIG would you say?

Thanks

[knighty]

My personal belief about mig welding is its for things like roll cage tubing with something like 2mm wall section.......on thin gauge bodywork, it goes all blue around the edges which basically means its brittle around the edges.......this is why major motor manufacturers now mig-braze their body shells together.......some people swear by migs, but even tig aint brilliant - but you can controll the amount of heat you pump in with the tig foot pedal, as the same blue-brittle effect can happen around the edges, hence people heat treat tig welded components.......nickel-bronze brazing with a gas fluxer is a really nice "home-builder" solution, the likes of Lotus and Lola were doing it in the 1960's

yes, yes, yes......the stresses caused by a mig cause big"pings" when you take a component out of a jig - dosent happen with brazing

as for goggles, I used to use the cheap plastic welders glasses sold at specialist tool and welding shops, they were like a really heavy tint pair of sunglasses - worked a treat.

[zefarelly]

Originally Posted by knighty

as for goggles, I used to use the cheap plastic welders glasses sold at specialist tool and welding shops, they were like a really heavy tint pair of sunglasses - worked a treat.

got to look cool whilst working as well

I've got one of those auto tint welkding masks for Mig, very good I think

and some dark green goggles for brazing

[kmsport]

dont Tig the job yourself if you've no experience....good tigging is supposed to look like Grandmas sewing!