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I've also heard this.

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Fair call - I guess it's another case of familiarity breeding comtempt.

coop...

looks like you have done a good job from the little pictures but you have welded on new panels. i could not see any big surface area welds on your ute. when repairing rust this is what we are talking about. it can be done but compitaincy has to be much higher with an oxy. yes panel beaters did use them... until migs, then spot welders came along. learning the art of the oxy is a long and difficult process, as i am sure you would know and one that is not recomended to be learnt by yourself...

something to known of brazing... it can encourage rust

lol that would be silly, then i'd have to go back and edit my first post so it is correct and then rant about it...

I went and looked it up so i know what's right.

I think it's ok to fix rust outs brazing if you follow procedures and have no other options.

don't braze your rollcage, frame, or other load bearing structures.

...brazed joints are generally not as strong as welded joints. Careful matching of joint geometry to the forces acting on the joint, however, can often lead to very strong brazed joints...
{which means don't engineer if you're not up to doing your research..}

now if someone made some sheet metal flares, that would be the way to attach em.

Heh, you're supposed to delete the reference to wikipedia and pretend you came up with all that!

I am partially correct. a tig would be best.

from : http://en.wikipedia.org/wiki/Brazing

...Common brazements are about 1/3 as strong as the materials they join because the metals partially dissolve each other at the interface and usually the grain structure and joint alloy is uncontrolled. To create high-strength brazes, sometimes a brazement can be annealed, or cooled at a controlled rate, so that the joint's grain structure and alloying is controlled...

Brazing strength - joint geometry - Brazing is different from welding, where even higher temperatures are used, the base material melts and the filler material (if used at all) has the same composition as the base material. Given two joints with the same geometry, brazed joints are generally not as strong as welded joints. Careful matching of joint geometry to the forces acting on the joint, however, can often lead to very strong brazed joints. The butt joint is the weakest geometry for tensile forces. The lap joint is much stronger, as it resists through shearing action rather than tensile pull and its surface area is much larger. To get braze joints roughly equivalent to a weld, a general rule of thumb is to make the overlap equal to 3 times the thickness of the pieces of metal being joined...

Advantages over welding

The lower temperature of brazing and brass-welding is less likely to distort the work piece, significantly change the crystalline structure (create a heat affected zone) or induce thermal stresses. For example, when large iron castings crack, it is almost always impractical to repair them with welding. In order to weld cast-iron without recracking it from thermal stress, the work piece must be hot-soaked to 1600

if you look the frame is brazed together - it's actually stronger than the steel it's holding.

the brazing is more brittle than the steel. more or less brittle than a weld? dunno...

For small holes. . .

Put some copper behind the hole.

Weld from the front.

Grind and done!

The weld will not stick to the copper, it supports the molten blob.

I use a bit of 1/2" copper pipe bashed flat. . .

Try it, you will be surprised

oxy + brazing. will work just fine.

in highschool shop i used to braze thin sheet to thick walled pipe and bar stock to make oil lamps and random stuff. use a small tip.

if you look the frame is brazed together - it's actually stronger than the steel it's holding.


I could be wrong, but that's hat i've seen and experienced myself.

the brazing is more brittle than the steel. more or less brittle than a weld? dunno...

ive got a lot of holes in my coupe im just wondering for the bigger ones should i cut a rough circle and weld it on then grind the weld or just try to fill the holes?