Brazing steel sheet

Does it have to be brazed? Silver solder would be easier, lower melting temperature.

Lionel

It has to be of MOTable strength. The MOT tester should be okay with it being brazed, but I'm not sure if silver solder would be acceptable - is there much difference in strength?

-- Wally

Silver solder not acceptable AFAIK for MOT.

Lionel

Brazing is most definitely NOT OK for an MOT. Some years ago the standards were tightened up and all structural work must be welded.

Regards

Kevin

It would depend what needed soldering/brazing. I've fixed holes in alloy exhausts with ali soft solder and had no queries on an MOT. As far as bodywork repairs are concerned ( i.e. none structural ) the key factor seems to be smoothness of the surface - which is why a door repair made with ali gauze and plastic padding will merit a pass, though I should imagine that there are some guidelines that would apply if the repair was anywhere near the hinge mounts.

Regards,

Unless the original was done like that.

Any repairs to floor/sill/chassis or any "structural part" must be welded if it's not a bolt on part.

If I did braze (which I wouldn't) I certainly wouldn't let on to the MOT inspector - The rules are long and complex and can sometimes be interpreted differently.

-- Steve Blackmore

Given that a _good_ brazed joint (even with joggled overlap areas to allow for a flush leaded finish) will be as strong, if not stronger, than a messy MIG job or any spot welded job, I would much prefer the brazed job. The important thing is that the finish should be so good that the inspector doesn't know that there has been a repair :-)

Mark Rand (My repairs are _very_ obvious) RTFM

That is probably true, but the book that the MOT inspectors go by says Brazing = Fail. But how many MOT inspectors could tell the difference between a brazed and a welded joint, especially once painted and undersealed is another thing !

Regards

Kevin

: : That is probably true, but the book that the MOT inspectors go by says : Brazing = Fail. But how many MOT inspectors could tell the difference : between a brazed and a welded joint, especially once painted and undersealed : is another thing ! : : Regards : : Kevin :

I am ignorant of MOT legislation but my experience in other branches of engineering legislation would lead me to believe that the law would not be prescriptive or specific about the techniques but would require adequacy of repair. Conformance with voluntary or official codes of practice may be a way of demonstrating adequacy.

chrisR

: That is probably true, but the book that the MOT inspectors go by says : Brazing = Fail. But how many MOT inspectors could tell the difference : between a brazed and a welded joint, especially once painted and undersealed : is another thing ! : : Regards : : Kevin : Suppose it was a re-brazed joint on an old motor cycle frame would that automatically fail then? ChrisR

This is a quote from Classic Cars, September 2003 who in turn are probably quoting from the MOT testers handbook;

"Repairs to bodywork must restore the strength of the structure to virtually the same as new. In practice this means only seam welding of patch repairs is acceptable, and spot welds can only be used where they were originally. Brazing, soldering and glasfibre are unacceptable methods of repair -unless they were used in the original manufacturing process."

I think you would find that any brazed repair spotted by an MOT tester would cause a fail, regardless of the quality of the joint. Doesn't seem particularly fair, but those are the rules. (maybe there is an MOT tester out there who could confirm if any latitude is allowed on this?)

Regards

Kevin

And I've been told by my local body shop that it must be continuous welding, not spot welding.

Dave

if its spot welded (mig) and skimmed with filler they will nether now the differance, i have the wheel arch to prove it!!

That is what the "book" says.

Had a chat with my cousin last night, who is a tester, lattitute is pretty well in the eye of the tester and in "his opinion" at the time of the test. If they want they can always find something if you piss them off. You can appeal, but must pay to have it re-tested, usually at one of the HGV testing centres. They may ask that you remove all paint, underseal, filler etc to examine the joint and will almost certainly find something else if they look hard enough ;)

Best to seam weld in the first place.

-- Steve Blackmore