Question for welding experts...

razorhunter · Dec 12, 2004

Guys,
I just obtained an oxy/acet torch set up EXACTLY like the one shown here: http://www.harriscal.com/2003/2003port-a-torch.asp

It has a 20cu ft. oxy tank and a 10cu ft acetylene tank.
I will be using it mostly for heat treating/striping titanium and also small heat treat jobs.
Could you guys give me an idea of approximately how long of a running time I will get with this rig? I'm trying to decide if I need to get a larger set up or possibly larger tanks or not.
I realize your responses may be only guesstimates, as even I'm not yet sure what regulator settings I will be running.
Just a good idea would help me out fellas.
Thanks guys!

faramir · Dec 12, 2004

Can;t help you with figures but for what it's worth you're only paying for the gas from now on - you get whatever mileage you get from those two bottles and then it'sup to a refill. A pairof bigger bottles would nly mean longer time between bottle refills, not lower costs or anything like that. Why waste more money on something that means no more than simple inconvenience when it finally comes up ?

razorhunter · Dec 12, 2004

feramir,
You are correct, however, if I don't get a decent amount of run time, then I will have to travel 30 min to the nearest welding supply house, and then 30min back. Not to mention the fact that they are closed on Saturday, and I would have to leave work early during the week just to get there. I work 8-5pm every weekday.
I figured I would MOST LIKELY get enough run time out of these, but having little experience welding, I really have no idea how long they will last. I'm sure someone around here either has this same rig, OR knows the approximate run time.
Thanks for your input kind sir!

Gib Guignard · Dec 13, 2004

Judging from the photo of your rig the first change I would is to get larger cylinders. The time that you have if you are cutting with it will be VERY short. Get the biggest cylinders you can handle. Gib

Tom Anderson · Dec 13, 2004

Depending on your torch tip and settings, you'll get about 15 minutes gascutting time with that setup. Welding or brazing won't burn up the oxygen as much.

Those tank sizes are convenient for quick junk yard runs, but bigger tanks make more sense in the shop if you're going to use it on a daily basis.

Walt2 · Dec 13, 2004

Definitely larger bottles. As stated above, depending on the size tips and pressures used, these small bottles do not last long. If you are using a rosebud type tip for heating, it will empty the Acetylene bottle faster than with smaller tips and if you are using larger cutting tips and higher O2 pressure, your O2 will deplete faster than with smaller tips. These bottles are only good for carrying to small "quickie" jobs and that is all.

KennyC · Dec 13, 2004

no idea on the runtime, but run the set with the acetylene at 7psi and oxygen at 20 psi for welding/flamestriping/everything else other than cutting.

razorhunter · Dec 13, 2004

Thanks guys!
Kenny,
I assume you do a little flamestriping yourself? That's cool! I will try your settings. I was wondering what acetylene setting to use. I figured 25 on oxy, but I will try what you suggest first. Thanks guys!

sparky-01 · Dec 14, 2004

ive tryed acetylene myself ,its way to expensive and the heat is consentrated into too small an area. i bilt a forge nozzle out of cheep plumbing suplys and use it as a hand held torch for hardening , it works great and it runs on a 20lb propane tank, its a lot cheeper .

Gib Guignard · Dec 14, 2004

I run my settings as low as I can when soldering using a ooo tip no more than 5psi
if cutting I raise the 02 to whatever I need maybe 20psi, on thick steel over 1/2" I may go to 40psi. The thing to remember is if you don't have enough heat then raise the pressure, be careful about th ac pressure keep it as low as possible. If you find that when cutting you think you need a larger tip don't get one just raise the pressure of the 02 that will go a very long way and develop technique, there is no substitute for being steady, shacks just don't work. Gib

jhiggins · Dec 14, 2004

That Harris outfit will serve you well for a long time. I have the same rig, but with 40 cubic-foot bottles. They were $100 apiece (filled) here in NH, so be prepared for an additional outlay of cash if larger bottles are your desire. I'm using my rig to do basically what you are doing, and a refill lasts me about two months, providing I don't find some old truck with some dandy leaf springs out in the woods. That very possibility may be a good reason to keep your twenties, if only for backup at least. Nothing worse than running out of gas... or beer.