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Timleech
08-17-2001, 02:51 AM
Get yourself a sheet metal (stepped) nozzle for that sort of thickness.

Tim

neonman
03-03-2006, 09:00 PM
Well, I finally went out and got a gas rig. I've been wanting one for a while, but putting it off. Finally had to cut something I couldn't cut any other way.

My first try, and I know I need a class, but...

I was cutting 11 ga steel, and it started out real nice for about the first half inch or so, then I got this melted blob, and it just went bad from there.

Any comments on how to recover from that/ how to avoid the blob in the first place?

neonman

tattoomike68
03-03-2006, 09:06 PM
turn the gas up a little hotter, lean the torch into the work like it was a chisel, hit the O2 and move fast.

dont go slow.

JIMofalltrades031
03-03-2006, 09:20 PM
You are using the cutting torch and tip?

bob308
03-03-2006, 09:54 PM
for 11ga. you should be using a 00 tip and keep it clean.

torker
03-03-2006, 10:07 PM
neonman, I cut miles of this stuff for sawmill chuting etc. Set up your torch with the recommended tip size for the material.
Line up a preheater (one of the little outside holes) so it will be directly inline with the cut line. Then tighten the tip into the torch head.
Set the gas at 5 and 25 (I cut everything under an inch with this setting).
Fire up the torch and like Mike says...tilt the torch head about 20 degrees back and drag it towards you.
You are best off to use a straight edge so you can concentrate on keeping the preheaters about 1/16" off the metal. The rearmost preheaters will be a bit too close but they do little when tilting the torch head back anyway.
Russ

CCWKen
03-03-2006, 10:43 PM
Yep, the thinner the material the harder it is to stay ahead. Pick up the speed and don't dilly-dally. http://bbs.homeshopmachinist.net//wink.gif

neonman
03-04-2006, 07:35 AM
Thanks for the tips guys, I think I had the
gas regs set too low.

neonman

Evan
03-06-2006, 11:03 AM
bump

kf1002002
03-06-2006, 05:05 PM
Since we're on the subject of gas cutting and welding will someone answer a question for me? I've seen propane used in place of acetylene for the fuel. Is there a problem or advantage with this? What about pressure settings?

Ken

Timleech
03-06-2006, 06:06 PM
<font face="Verdana, Arial" size="2">Originally posted by kf1002002:
Since we're on the subject of gas cutting and welding will someone answer a question for me? I've seen propane used in place of acetylene for the fuel. Is there a problem or advantage with this? What about pressure settings?

Ken</font>

Propane is OK for run of the mill cutting, & cheaper and maybe safer than acetylene. I used it for a couple of years, went back to acetylene & wouldn't go back to propane unless forced. Acetylene gives a more localised heat, enables quicker pre-heat for delicate jobs such as cutting off seized nuts without ruining the bolt thread or just working in awkward spaces. You can't get the special nozzles such as sheet metal or rivet cutting for propane, at least I've never seen any.
DON'T use the same regulator for both. Propane can ruin an acetylene regulator, and acetylene regulators are limited to safe pressure (about 15 psi), propane regulators may not be so could be very dodgy on acetylene. I think these days most fuel hoses are OK for both gases but worth checking whether yours are.

Tim

Warren
03-06-2006, 07:54 PM
Another thing worth looking at if you cut a lot of thin sheet with torch. Most of the torch makers have a special tip for thinnner sheet metals. It has a stepped shape & fewer preheat holes

kf1002002
03-06-2006, 09:48 PM
Thanks Tim. The moral appears to be propane regulator for propane and actylene regulator for acetylene. Reading between the lines of your answer you seem to imply that you use different nozzles for propane also.

Ken

Timleech
03-07-2006, 04:03 AM
<font face="Verdana, Arial" size="2">Originally posted by kf1002002:
Reading between the lines of your answer you seem to imply that you use different nozzles for propane also.

Ken</font>

That's right, at least as far as self-mixing nozzles go. Propane cutting nozzles, at least in the UK, are generally 2-piece affairs.
Another thing to bear in mind is that oxy-propane is pretty much useless for welding.

Tim