Guinness
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| posted on 29/8/06 at 03:32 PM |
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He looks to be going hard at it in this thread.
http://www.locostbuilders.co.uk/viewthread.php?tid=46376
Poor lad, hasn't even got a visor on!
Mike
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DIY Si
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| posted on 29/8/06 at 04:17 PM |
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Perhaps he's gone at it too hard and gone pop?! Is Trevor doing mig/tig or the 'bronze welding' in that vid that can be seen on
the bare chassis?
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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iank
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| posted on 29/8/06 at 04:42 PM |
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Bronze welding is an oxy-acetylene process so it's not that 
Looks like MIG to me.
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DIY Si
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| posted on 29/8/06 at 04:48 PM |
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So what's the golden coloured stuff on this chassis then? Not being picky/awkward, just curious.
 
Rescued attachment chassis1.jpg
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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iank
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| posted on 29/8/06 at 05:34 PM |
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Looks like bronze to me maybe they have a funky way of migging with bronze wire? That robot was certainly electrically welding not holding a
torch.
Arch are always using gas torches in their pictures I've seen (green flames since they were adding flux to the gas).
http://www.archmotor.co.uk/history.htm
Later: Google shows it is indeed possible to MIG with bronze.
http://www.mig-welding.co.uk/brazing.htm
[Edited on 29/8/06 by iank]
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DIY Si
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| posted on 29/8/06 at 05:55 PM |
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Looks like that could be a trick worth learning.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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coozer
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| posted on 29/8/06 at 07:54 PM |
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Hmm.. after all that I'm still wondering about brazing. Does it put too much heat into the chassis
I know its more flexible than welding but is it strong enough?
The reason I ask is because I have gas bottles and no mig. Lots of brazing kit but no MIG kit.
I've also got an arc welder but thats something else...
1972 V8 Jago
1980 Z750
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DIY Si
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| posted on 29/8/06 at 08:00 PM |
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On that website he cracks/bends a weld, but the steel breaks at the edge of the weld rather than the weld itself cracking. As for thicker stuff, I
don't know what would happen.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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iank
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| posted on 30/8/06 at 08:15 AM |
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It puts much less heat into the chassis, since the melting point of the filler rod is much less than steel. Thus very little distortion. It also
means if you bend a tube you can remove it buy melting out the bronze rather than cutting and grinding.
Need to be careful with the term brazing since it's the name of the process and is often associated with using brass as the filler, which
isn't up to the job of chassis construction. This terminoligy thing has caused flame wars on this subject before.
Try to get the 750mc book I linked above from the library (probably not worth buying just for the chassis costruction section).
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David Jenkins
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| posted on 30/8/06 at 08:22 AM |
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You'll be lucky to buy a copy of that 750 book - last time I saw one on eBay it was going for stupid money!
It does give a very good description of the bronze-brazing technique, including how to set up the metal to create the strongest joints. It's
quite a different technique.
The authors also illustrate the strength of the technique by describing how one of them piled into the end of the pit wall at 100+ mph and survived,
protected by a bronze-brazed spaceframe!
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iank
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| posted on 30/8/06 at 08:49 AM |
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quote:
Originally posted by David Jenkins
You'll be lucky to buy a copy of that 750 book - last time I saw one on eBay it was going for stupid money!
...
The authors also illustrate the strength of the technique by describing how one of them piled into the end of the pit wall at 100+ mph and survived,
protected by a bronze-brazed spaceframe!
just seen the price on Amazon. Anyone want to buy my mint copy for £200
He only just survived that crash, needed his heart restarting by on track guys IIRC.
The spaceframe survived extremely well IIRC, but the body just can't take that kind of deceleration.
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mcerd1
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| posted on 30/8/06 at 08:50 AM |
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quote:
Originally posted by Locost Novice
it claims to be as strong as the metal around it
Yeh, but its not really attached to the metal - its glorified glue
a proper weld actually fuses two bits of metal together into one
brazing is better than the glue stuff, but you'd be as well to borrow, hire or buy a mig - its far stronger as well as easier to do
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David Jenkins
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| posted on 30/8/06 at 08:58 AM |
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quote:
Originally posted by iank
He only just survived that crash, needed his heart restarting by on track guys IIRC.
The spaceframe survived extremely well IIRC, but the body just can't take that kind of deceleration.
Yes - fortunately a surgeon was standing nearby enjoying an ice-cream when the accident happened, so he was fortunate to be given medical attention
within seconds. Apparently he had almost no bodily injury as the spaceframe protected him but, as you say, humans aren't designed to hit
seatbelts at that speed!
David
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iank
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| posted on 30/8/06 at 09:09 AM |
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quote:
Originally posted by mcerd1
brazing is better than the glue stuff, but you'd be as well to borrow, hire or buy a mig - its far stronger as well as easier to do
Properly done a bronze weld is stronger than the steel it joins, the same as a 'proper' weld.
MIG might be easier, but isn't 'far stronger'.
The open wheel racers and caterham have been using bronze welds for 50 years which should tell you something about their strength.
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David Jenkins
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| posted on 30/8/06 at 09:14 AM |
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It's worth bearing in mind that bronze-brazing isn't the answer to life, the universe and everything.
The bronze rods are quite expensive, joints have to be far more accurate, the parts need to be cut and shaped differently when compared to welded
joints, and cleanliness is paramount. You also have to deal with oxy-acetylene and flux.
I wouldn't mind giving it a try though, as I've done loads of silver soldering in the past and the technique isn't so much
different.
David
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iank
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| posted on 30/8/06 at 09:21 AM |
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quote:
Originally posted by David Jenkins
It's worth bearing in mind that bronze-brazing isn't the answer to life, the universe and everything.
The bronze rods are quite expensive, joints have to be far more accurate, the parts need to be cut and shaped differently when compared to welded
joints, and cleanliness is paramount. You also have to deal with oxy-acetylene and flux.
I wouldn't mind giving it a try though, as I've done loads of silver soldering in the past and the technique isn't so much
different.
David
I agree, I just get irritated by the 'isn't as strong' meme. Which I think comes from the MOT test not allowing bazed joints. The
key is 'properly done' it needs lots of time and some skill to get right, getting a strong but ugly joint with MIG is much easier,
backstreet bodge to pass garages wouldn't be able to get strong bronze joints reliably.
MIG brazing looks interesting and might just have the cost disadvantage.
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David Jenkins
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| posted on 30/8/06 at 09:57 AM |
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Sorry - didn't mean to lecture you!
Just trying to give everyone a clear picture of bronze brazing... it's not a simple and easy alternative to MIG welding, as it has its own skill
requirements, and 'ups-and-downs'.
[Edited on 30/8/06 by David Jenkins]
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stevebubs
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| posted on 30/8/06 at 11:42 AM |
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I brazed my sump pan together when fitting my zetec. Tricky to get right when learning but once you get the knack it's great.
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David Jenkins
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| posted on 30/8/06 at 12:02 PM |
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Steve,
I guess that's ordinary brass brazing, rather than bronze brazing?
David
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MikeRJ
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| posted on 30/8/06 at 07:25 PM |
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I've done what I thought was "brazing" before, but know I don't know if it was or not! I used an oxy-acetylene torch with
brass coloured rods and flux, the steel had to be heated red hot to get the brass/bronze to melt and fuse the joint together.
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907
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| posted on 30/8/06 at 08:01 PM |
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Brass runs like solder, thinly coats the sheet.
It's used for capillary joints, i.e. tube slid inside another tube.
Bronze forms a weld bead, hence it's called bronze welding.
Not to be confused with silver solder which is, as far as surface tension is concerned, a little more bead forming than brass.
Confusing ennit.
Paul G
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MikeRJ
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| posted on 30/8/06 at 10:05 PM |
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Yup! This definately formed a proper bead, was used to join some chassis members on a kart I built years ago.
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coozer
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| posted on 2/9/06 at 12:23 PM |
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Might be just me but I think brazing is easier than Migging! You have more control and can see easier whats going on.
Thanks everyone, I was meaning brazing with brass rods but didnt realise bronze brazing was stronger.
I have gas bottles here but no MIG welder so thats why I was asking.
Cheers
Steve
1972 V8 Jago
1980 Z750
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caber
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| posted on 2/9/06 at 09:47 PM |
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Has anyone used TIG for bronze welding or brazing? I would like to know the trick to this so I can retire my oxy acetelene kit
TIA
Caber
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violentblue
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| posted on 3/9/06 at 12:46 AM |
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quote:
Originally posted by coozer
The Aston Martin DB9 has a nice glued together chassis.
If its good for them its good for anything, just not for me thank you.
I would ask if brass brazing is an alternative to migging the chassis up?
Doing dome reading through some chassis welding books, one autor swears that brasing a tubular chassis can be as strong as welding, because the lower
temps ton't cause as much internal stresses.
not entirely sure I'm ready to trust that 100% but it came from an expert so there's got to be a little credibility behind it.
a few pics of my other projects
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