Cutting metal with torch

You've gotten some good advice. My 2 cents are to find someone who really knows how to use a torch to show you how to use it. It only takes a few minutes to show you how to get the flame to the correct color and height. Knowing how to use the regulators is also important as well as other noises/smells to look out for. A training video might also be good.

I'm concerned that the tourch blew up and how your cutting metal. It sounds like your not blowing the slag away and it's probably pluggin up the tip and causing flashback in the torch it's self. You probably had a fire in the torch that melted the brass and leaked acetylene that ignighted. Did you hear a high pitch squeel or notice the torch getting hot?

Since most torches don't have flashback protectors I strongly suggest you get some if their not already on.

Also, be careful of your Acetylene pressure and don't let it go into the danger zone as it could explode.

On the pressures I have a big torch and like to run 10-12 for the acetline and 70 pounds for the O2. for cutting to really blow the slag away. For welding I like a balanced 3-10 pounds depending on the tip. I'm mostly below 5 as arc weldiong is better for the real big stuff.

Good luck and stay safe

Here is the location of one of the best descriptions of torch cutting I have seen posted on this forum. It is in the archives.

GAS SETTINGS FOR CUTTING AND WELDING
Posted by T_Bone on January 24, 2002 at 16:36:44 from (207.173.149.113):
In Reply to: Re: Re: Re: Is Gas Welding Practical? posted by Tim Briggs on January 24, 2002 at 13:43:46:

After reading and following T_Bone's advice, my torch cutting showed great improvement. Yours will too.

BTW, I've read hundreds of T_Bone's postings, and the tone of this one is unusual for him. It sounds a little giddy to me. I've always wondered what kind of a strange mood he was in when he wrote it. Absolutely no disrespect intended. T_Bone is one of the few living individuals who I admire (and none of the others are politicians or religious leaders.)

All the best, Stan

I would like a detailed discription of what happened when your torch exploded as it would of interest to the group to fully understand the safety concerns while using a torch so this problem does not re-occur.

Your using too much preheat for the thickness of metal your cutting along with a dirty cutting tip is whats causing the problems your having. It's most likely your cutting speed is also too slow but without correcting the first two problems, you will not be able to tell.

What happens when you use too much preheat? The molten metal is very liquid in width and when you try to blow the heated molten puddle with oxygen, the puddle runs to the back of the direction your cutting and reforms a weak bond behind your cutting tip. This new molten puddle is high enriched oxygen and carbon making it very hard and brittle thus when your try to reheat this area it takes longer to preheat as well resist being blown out by the oxygen from the hardness of the metal and will cause molten metal too blow out and back onto the cutter.

With the correct preheat flame temperature the molten puddle will not form as wide thus you will achive a narrow cut without any molten puddle run back.

With a dirty cutting tip several problems arise. First with the preheat orifices drity you will not achive a even preheat to start the cut. It will take more preheat to start the cut with a dirty tip than with a clean tip. Second once preheat has been established then the if the center tip orifice is not cleaned then slag will collect on the backside of the base metal and the cut face will be ragged.

The above problems will cause a slower forward cutting speed thus once again cause base metal over heating allowing the harden slag to refrom behind the cutting tip.

Although not one of my better written posts, Stan has refferenced a good thread to read.

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Hi Stan,

I was on some new medication at that time. Although I made it sound like Branden had bothered me with his geezer comment, he really didn't and I was joking alot in that post. I see now that wasn't the correct thing to do as Branden did not post very much after that and that is a shame. I changed my writing style alot after those inappropriate comments I made.

T_Bone

• Cutting Torch Tip Cleaning