Hi i have just read it is illegal to repair cars using brazing i presume this is for a mot
is this right ?
+ Am i right in thinking Caterham braze there chassis
will fail if chassis repairs are done by brazing,i saw a caterham chassis being made on telly,they were welding it
Yes you're right it is illegal to braze a repair for MoT, unless it is a repair to something which was brazed originally (can't think of
anything offhand).
Not sure about Caterham brazing their chassis, be surprised if they still do in these days of Mig & Tig, but if you are the designer & say the
chassis is designed to be brazed that's fine.
The ruling makes no sense of course as brazing can be stronger than welding depending on the type of joint, materials etc
Caterham chassis are bronze welded.
Phil
What is the difference between brazing and bronze welding?
quote:
Originally posted by Hellfire
Caterham chassis are bronze welded.
Phil
quote:
Originally posted by Mark Allanson
What is the difference between brazing and bronze welding?
It is still all brazing which ever 'filler' rod you are using, the only metal you can bronze weld is bronze. With brazing you do not alter the metals to be joined, it is a chemical action which bonds the metals together through capilliary action.
Read and enjoy dudes
IIRC most commercial bronze welding used to be done with oxy/acet using a gas flux unit
http://7faq.com/owbase/ow.asp?NotesOnWelding
[Edited on 13/9/08 by Wadders]
My other half is a jeweller - what she refers to as soldering, most people would call brazing - she uses a filler alloy based on the metal being
joined (silver or gold), and a micro oxy-hydrogen torch as the heat source.
According to her, the only difference between soldering and brazing is the temperature - brazing is at a much higher temperature, however the metals
being joined are never melted so its definitely not welding.
Nick
Yes it is an MOT failure , I brazed a lot of my MGB and an hillman imp before that years ago and in reality it can be stronger than poor welding .I
think the reason it was banned for MOT repairs is that it is actually possible to braze badly rusted panels etc whereas they would have to be replaced
to weld them.Having said that as long as it is painted and undersealed afterwards the tester wont actually be able to tell.
I even resorted to pop rivets and self taps years ago to get old bangers MOTed , you just needed to be good at disguising things.I wouldnt do it
nowadays as if a modern car is rusty enough to need major work then it is only worth scrapping unless its a classic.
Paul.
There are two types of brazing in my mind from my old NCB days.. brass & bronze... bronze being a lot stronger than brass
Brass brazing is quite low temp and ideal for none structural where a good seal is required.. ie sumps etc. Doing a peel test on welded parts you get
a tear in the original metal alongside the weld where as with brass brazing the brass tears and the two mediums remain intact. Not familiar with
bronze tho..
I'm sure Caterham used bronze brazed chassis but don't quote me. Although I know a lot of competition bikes, trials, motocross bikes have
brazed frames because it adds flexibility.
quote:
Originally posted by Mark Allanson
It is still all brazing which ever 'filler' rod you are using, the only metal you can bronze weld is bronze. With brazing you do not alter the metals to be joined, it is a chemical action which bonds the metals together through capilliary action.