but, that was almost 50 years ago, i know MIG is now around but with only about 10 minutes using it am i better off brazing or welding a chassis together? bearing in mind i start off with no equipment apart from a a couple of soldering irons
chris
reading "high speed low cost" Allan has explained the pros and cons of welding and brazing. and explained why he brazed the chassis together
as its more friendly for new comers to learn.
but, that was almost 50 years ago, i know MIG is now around but with only about 10 minutes using it am i better off brazing or welding a chassis
together? bearing in mind i start off with no equipment apart from a a couple of soldering irons
chris
Bronze brazing is good, but not ordinary brass brazing. However, it's a different construction method (the joints will be a different shape) and
you will need oxy-acetylene to do it properly.
If you have the gas welding equipment, and the skill to use it, then bronze brazing is something to consider. Otherwise - use MIG! 
I would opt for brazing if just making something for yourself. Mig is fine but you have less control. Then there is tig welding but the kit is expensive but very similar to gas welding ie you create a molten pool and add filler rod.
If you like the contole of brazing you will love Tig welding.
I think that overall, brazing if not an option for a road chassis.
quote:
Originally posted by designer
I think that overall, brazing if not an option for a road chassis.
so, by the sounds of it brazing is easier and easier to reverse if you muck up, as your not melting the 2 parts just heating them up.
so what about price? whats cheaper, MIG or brazing?
TIG is out of the question due to price, and for brazing do i only need a torch and some brazing rod? or is their special equipment i need for a good
strong hold?
Only an oxy-acetylene torch (maybe oxy-propane) will do the job - you won't do a chassis with a domestic/DIY/plumber's propane torch! I can
just about braze small parts in a hearth when using a propane torch, as you have to get the work up to a minimum temp of dull red, preferably to
orange.
A full kit of oxy-acetylene or oxy-propane is going to be similar in cost to MIG... plus you have the problems of safety, skill levels, storage, etc.
You will also have to pay for 2 bottle rentals + refills instead of 1.
As I said earlier - if you've already got the gas welding kit and know how to use it then it's an option... otherwise... no.
Bronze-brazing rods & the correct flux can also be quite expensive.
[Edited on 12/2/11 by David Jenkins]
Being of the "Old School" of racing, I have used both ozy-acetylene and mig, I still have both.
That said the mig is easier for the beginner, the Nicol-bronze type of brazing that was used in the 50's and 60's takes a lot of practice
because of temperature control.
This type of brazing was used mostly with 4130 alloy (chromoly tubing) it can be used on mild steel. all of the suspension on my Datsun racecar was
nicol-bronze brazed.
My Locost is mig welded.
9% Nickel Bronze rods are not cheap (£70 per Kg)
Linky
As mentioned Oxy-Acetylene is really needed to get the parts hot enough (I now use Oxy-Mapp Gas as I don't have Acetylene anymore).
Joint fit needs to be good and really clean metal.
Flux is used and is a pain to clean off afterwards.
As a lot of heat is input, there can be a fair bit of distortion.
Mig is now the best DIY option for chassis work (Allan did not have the luxury of cheap Mig welders back in the 60's).
I still use a little nickel-bronze 'welding' when working on old racing chassis.
[Edited on 12/2/11 by minitici]
How accurate at you? MIG works well with small gaps - therefore if you're not 100% accurate MIG is fantastic. Brazing needs very accurate joints, studious cleaning before and after (i believe - could be wrong here). This also means MIG will be faster to assemble as you get damned close with the metal, quick rub, weld it, and your done.
Mig IS easier no question. But Brazing is how Caterhams are made... to this day I believe.
Lotus had Brazed chassis in their earlier F1 cars. No question as to it's strength.
But it is harder than pulling a trigger while the gun head is pointing in the general direction of the intended weld.
TIG is nice but a decent kit is half way to buying A Caterham kit... and it's painfully tedious/slow as well as needing genuine aquired skill to
do decent welds.
Arch used to bronze weld chassis for Caterham but they are now built by Caged using CAD process and robot welded since 2005. The old way depends on you being deadly accurate with your cuts and cleaning all your ends up. I brazed and gas welded but once I discovered mig it got left for heating stuck bolts. Unless you want it for bragging rights just use the simple quick and cost effective method. Even Caterham have caught up with new technology now.
ok, seems like MIG is the best choice.
now next sub question is what amperage should i get (tight budget) and should i get the gasless ones as i will be welding outside in a garden, and i
think the gas from a gas welder will just blow away in the wind...
quote:
Originally posted by designer
I think that overall, brazing if not an option for a road chassis.
quote:
Originally posted by designer
I think that overall, brazing if not an option for a road chassis.
quote:
Originally posted by peteff
Arch used to bronze weld chassis for Caterham but they are now built by Caged using CAD process and robot welded since 2005. The old way depends on you being deadly accurate with your cuts and cleaning all your ends up. I brazed and gas welded but once I discovered mig it got left for heating stuck bolts. Unless you want it for bragging rights just use the simple quick and cost effective method. Even Caterham have caught up with new technology now.
thats perfectly fine and i think thats a good idea tacking it up and tacking it to someone who can weld !!
the chassis has been designed, its the terrapin chassis so not an awful lot needs doing.
will probably mean ill need a roof rack for the mini to carry it places but even so it shouldn't be too difficult
i know a local workshop that mends lorries maybe they can give it a go with a bit of money thrown their way.... i know they are aloud to do their own
projects, but maybe not a whole car though...
either way i do it, i need to finish reading the book first 
Sorry yes, Caged are doing the roll cages for the Superlight. There's a
nice picture of the chassis here with the roll cage in progress.
Here's a bit on their Caterham contract with a few videos of the
equipment further down. It's not exactly blokes in sheds any more 
[Edited on 13/2/11 by Peteff]
quote:
Originally posted by Peteff
Sorry yes, Caged are doing the roll cages for the Superlight. There's a nice picture of the chassis here with the roll cage in progress. Here's a bit on their Caterham contract with a few videos of the equipment further down. It's not exactly blokes in sheds any more
[Edited on 13/2/11 by Peteff]
the likes of Chapman and the original Lotus were brazed but thats not to say that if MIG technology had been around then as it is today they wouldnt have used it. I suspect a lot of what is considered 'de riguer' now, was just needs must back then. some old Lotus F1 cars used Imp style rubber donuts on the driveshafts for christ sake!