What rate are you all using CO2 at.?
How much to do a complete chassis.?

It all depends how good you are.

beginner 1/2 cougar going slowly, high gas rate.

dab hand, more current working at twice the pace, gas adjusted right down and properly cleaned material 1/8 cougar if not less.

A mig welder will make a poor welder look good, even if the results are not very strong as you learn technique.

Regards Mark

I've used almost two full bottles but then I welded in the floor and made a plated box transmission tunnel.

Are you talking big bottles or the smaller ones from machine mart etc.?

Cougars are the big industrial bottles, the little machine mart ones do not last that long at all in my experience... that was 20 years ago.

If you know your landlord well you could use pub gas, not as clean to weld with but cheap. Just use anti spatter spray which seems to help.

Regards Mark

Jeez, the old 'how long is a piece of string question'. It;ll depend enormously on where and what
you are welding, outside in high winds will need huge amounts.
Start with very low flow, just a hiss, on a test piece. If it spatterrs and pops like fook then increase
gradually till you get the frying bacon fizz sound.
Once you have the right setting a bottle pub sized should weld several chassis'

Avoid the "Machine Mart " size bottles as they last between 5 and 22 miliseconds .

This topic comes up from time to time, and I just don't understand why my experience of the little C02 bottles (a la Machine Mart) is so different...

I've welded my whole chassis including a fair bit of seam welding, and done some major patching on my daily drive - all on 5 600g bottles!

So that's less than £50 over the last 3 years (slow progress, I'll admit!) which is less than it would cost me to rent one of the big bottles for 12 months.

So the small bottles really are economical if you're not welding every day.

This is C02 mind... Argon or Argon/CO2 mix is lighter and doesn't last as long.

i asked a boc guy in glasgow for a pub bottle got a big one for £10 from him
had it two years now and i done a lot of weilding you can buy a fitting for it on ebay it works fine.