Most commercial operations use Dr Broco's all-purpose releasing agent these days. Broco, being 'oxy-thermic' will go through just about anything you need to cut, though mostly you're going to be cutting steel. I'm not going into the 'safety' of Broco use here but just give a couple of pointers to help you get the job done.
If you have a fair bit of cutting to do its often worth running a 2nd downline to the job. Its all too easy to wizz the burning gear down with a box of rods and start burning ASAP - then what happens when it turns out you need more rods, another washer or collet for the gun and the d/line has the burning gear on it? Rig a 2nd d/line and then you still have a 'freeway' for rods/tools/new gloves etc. Obviously, if the job is to cut a single 10" pipe you'll only need 2 rods anyway
Making sure your cut is fully
100% as you go is important. The last thing you need is to 'complete' your cut and find that the big, nasty lump of steel won't budge 'cos you've left 'bridges' in the cut - invariably they're gonna be underneath the sucker - just where you
don't want to be when the beast breaks loose
For years my 'anti-bridge' device was a piece of hacksaw blade (a common one at the time) - I'd burn a couple of rods then run the blade though the cut - if it wouldn't go all the way then I had a bridge and would go back to zapp it. But I still got bridges. Then, I had the good fortune to work with someone with more sense, Al Dodd. 'Doddy' would take a welding rod and bend it into a kind of 'S' shape. This was inserted at the start of his cut and was
never removed - he ran it along the cut finding bridges and when burning he'd run it back a few inches and let it hang there, still in the cut. Consiquently when the 'S' hook made it to the end of the cut, the cut
had to be 100% - simple schwimple!
My naff drawing of a tubular being cut gives a false impression - in reality, in dark water and with the weight of the material above crunching down on the cut - bridges don't stand out like a bulldogs nuts so you need to physically check the cut... 'Doddys' welding rod everytime!
Berko
