Oxy Acetylene Welding Challenge

[culp]

Hi,

I'm new around here, I'm currently restoring a 1972 Triumph GT6 thats very rusty. I bought an Oxy Acetylene set as I can't afford a decent MIG setup (I've got a cheap set but its not really up to the job) I have a Murex Saffire 5 set and it frightens me to death! I'm still experimenting and trying hard not to burn the house down. Currently I'm chopping out a fair acreage of rusty steel. I'm not sure how to set up the pressure on the gas bottles for cutting rather than welding any clues gratefully received.

Culp

 

[Weldingartisan]

Assuming you have covered the safety aspects (removing combustibles, fire extinguishers, etc, just to mention the obvious) and read the BOC or similar data on the safe storage and use of compressed gases, try this:
5 psi acetylene 30 psi oxygen. If you have cutting equipment with two oxygen valves plus the cutting lever, open the mixing chamber oxygen valve fully (the one on the handle next to the acetylene), no gas should escape. open the acetylene valve a quarter turn and ignite, once alight open the valve further until the black smoke almost stops. open the second the oxygen valve slowly until the feathering disappears and a clear blue cone is visable. Press the cutting lever whilst looking at the flame to check for a sharp cone (until the feathering just disappears).
In use: hold the torch tip at 90deg in both directions to the job for your (first cut start from an open edge) with the blue cone just touching the work, bring to red heat (almost instant with sheet metal) press the cutting lever and move the torch. Speed of cut will depend on tip size, material thickness etc., but if you move to fast it won't cut, too slow will weld itself together again! Good luck and watch out for the hot bits. W/A

 

[Tino]

For welding you would use only about 2lbf/in2 on both oxy and acetylene and for cutting the same for the acetylene but about 25-30lbf/in2 for the oxy,set a neutral flame with the cutting lever open. It,s a bit heavy for thin stuff though you may be better of using a cutting disc. Hope this helps

 

[Weldingartisan]

The trouble with running acetylene at 2psi on a single stage regulator is the problem of flame fluctuation and constantly having to adjust - hence the difficulties of keeping a neutral flame on small tips. 5psi is quite safe and will help prevent popping and backfiring from cutting less than perfect steel. W/A

 

[Tino]

The trouble with running acetylene at 2psi on a single stage regulator is the problem of flame fluctuation and constantly having to adjust - hence the difficulties of keeping a neutral flame on small tips. 5psi is quite safe and will help prevent popping and backfiring from cutting less than perfect steel. W/A

Good point, 5psi would be better on a single stage regulator

 

[piman]

Hello Culp,

oxy\acetylene has a few advantages over MIG sets but I don't believe that using the cutting torch is the best way to cut out your rusty parts.

I prefer to use an angle grinder or air chisel and occasionally an air saw. Aviation shears are good for accurate cutting of sheet or repair panels. I have used my oxy\acetylene welding torch on occasions where I just could not get access for any of the above, but it is not very clean or accurate.

Good luck with the GT6, my Triumph is a 2.5 P.I. engined Mk 1 2000.

Alec

 

[Mr J Morton]

I second piman. I restored my spitfire 1500 more than once (I've owned it far too long) and a grinder has always been my weapon of choice.

good luck

Jon

 

[culp]

Thanks

Thanks everybody for the help and pointers, much obliged

 

[zardoz]

Where are you based culp ?