Oxy-acetylene torch to cut and clean scrap metal?

Do you use one to cut and clean tough metal? And if so, how much did it cost for the initial set up?

I only light the torch when I have to

You can get a nice carry along setup for $330.00 from Harbor freight
Portable Welding Torch Kit w/ Oxygen & Acetylene Tanks

Check your local Craigs list >> There are several for sale there
chicago for sale "cutting torch" - craigslist

Plasma cutter would most likely be a better choice for cutting heavy melting steel. Thats what im currently looking into for the future.

We use a chop saw for trimming the catalytic converters we purchase.

I just bought one to use for a flat bed trailer (tractor trailer). Spent $230 on the kit. It is a little small and came with a 0 tip. Probably should have had a 1 or 2. Brought it at central tractor. It is a Hobart medium duty.

If you have never used a torch before, you are in for quite the learning curve. I burned thru the large tanks and still don't have a good feel for it.

Speaking of torches, this may be a fluke, but it has happened twice to me and I've also heard of an explosion that was fatal for a man. Goes like this: When cutting into a water tank or even a pipe, there are certain gases accumulated through oxidation, rust and other forces that are explosive. The fatal accident was with a torch on a large watertank. It was reported that there was never anything but water in that tank, but it took the man's life. As for myself, I had used a cutoff saw in my shop to cut down a water hydrant. The first one I did not know the history of, but assumed it was always underground and used for water only. The last one (this week) was removed from my farm where it had been hooked into a waterline for the last 25 years. These are the frostfree water hydrants......one brand is the Iowa hydrant but there are other brands. Anyhow, when the cutoff saw got through the outer core of the pipe, there was a mini-explosion; more like a puff which flashed but enough to scare a person. It was definitely a reaction of fire/spark vs forces within the pipe. Has anyone else experienced this ?

Originally Posted by mthomasdev

I just bought one to use for a flat bed trailer (tractor trailer). Spent $230 on the kit. It is a little small and came with a 0 tip. Probably should have had a 1 or 2. Brought it at central tractor. It is a Hobart medium duty.

If you have never used a torch before, you are in for quite the learning curve. I burned thru the large tanks and still don't have a good feel for it.

It may not be your fault. I set up a medium duty rig quite awhile back and never really got the hang of it. It's fine for brazing,gas welding,and cutting granite but it doesn't seem to cut steel very well.

Maybe it's asking a monkey to do a gorilla sized job ?

Originally Posted by eesakiwi

I know exactly what you are talking about yunkman. It was a couple of weeks ago when I read about it happening here in NZ.

What happened was a company was emptying a water pipeline, quite a long one & about 6 foot dia.
A worker was doing a inspection in part of the pipe while another worker was cutting it, quite a distance away.
The cutting torch ignited some flammable gases and the person doing the inspection was killed by the pressure blast.

What happened was this. When they 'dewatered' the pipeline, they did not open the top end of the pipeline to free air, the air was entering thru the outlet end.
Now this had caused a suction/vacuum in the pipe, this vacuum sucked in air from around the pipe in several places. Underground.

Unfortuanly underground is where flammable methane and such gases come from, the vacuum sucked some of these gases that were around the pipe, into the pipe and made a explosive gas mixture with the oxygen/air that entered thru the open end.

The gas cutting ignited it and sent a pressure blast up the pipe that hit the inspector and killed her.

More info here, I cannot find the actual inquiry report.

Danger under the streets: The Onehunga blast

The other thing to remember is that oxygen will react with oil/grease etc, explosively. The stream of pure oxygen from the cutting tip is enough to do it.
And tanks, even after they are washed out, will retain fuel etc in seams, a little bit of heat and it evaporates and there's now a explosive mixture.

If washing out a tank, use detergent in the water.

Many years ago in a very large scrap yard while heading to the unloading area fro my heavy melt noticed the yard foreman was about to blow out an injector line on one of the cranes using pure oxygen from the cutting torch.

I said hey Bob you mind waiting until I leave the yard before blow that injector line, when he asked me why, I told him he shouild read the warning on the oxyen guages.

Originally Posted by Faceball

I figured id share a story. My uncle worked on Caterpillar equipment for a big yard in California. He would tell us stories about having to repair fuel tanks on the underside of these earth movers and scrapers. I guess these tanks were huge, like 100 gallons or something. Instead of draining the tanks they would fill them to the brim with diesel fuel and weld on them to fill pin holes and cracks. I believe they were using a big MIG with an inert gas blanket tip or something.
Crazy, imagine welding on a tank that’s FULL of gas! The whole idea was to eliminate the O2 so things don’t go boom.
Amazing what you can do safely when you know what you are doing.

ps. Please don't try this. My uncle had over 40 years of welding experience and these were old man stories around the campfire. Be safe

Interesting story.

Would work with diesel but not with gasoline.

Originally Posted by junkfreak

There is difference between a welding tip and cutting tip.Might have been the problem.
Also the set up is different for cutting and welding.

Other things to consider cutting tips are sized,

Most popular brands of cutting torches desighned for acylene will accept propane tips, they do work but not as efficient as a torch specically made to burn natural or propane gas these torches have special mixing heads and these produce a much hotter flame.

What we refer to as cutting metal with a torch is much more than than, once the hot flame heats the metal red hot you squeeze the trigger shooting a stream of pure oxygen onto the hot zone. What happens now is that the oxygen actally burns the metal so what you get from burning lets say a six inch thich piece of metal is slag with perhaps a bit of molten metal created by the massive ampount of heat caused from burning.

When I sut metal thicker than six inches thick would weave the stream of oxygen off centre 1/8" side to side cut in such a way that the slag exiting the cut falls downward this way the heat retained in the slag pre heats the metal underneath.

When ever doing a largw job would order a liquid oxygen, comes in a big thermos is the equivalant of 18 large bottles of oxygen at a fraction of the price. The only downside is you have to use the bottle daily for hours at a time. The liquid oxygen requires refridgeration by using the bottle drawing off the contents refridgerates the contents otherwise the bottle will bleed off oxygen when not in use.

I used a torch made by Harris, burned propane.

Metal Thickness	Tip Size	Cutting Oxygen
Pressure*** PSIG
1/8"	000	20-25
1/4"	00	20-25
3/8"	0	25-30

I like Harris tips... So easy to clean.

Adding to what Alloy2 said about the Oxygen doing the cutting.

Dad had to cut thru a peice of Steel 1 inch thick by 6 inch wide.
He knew there was not enough Acetylene left to do the job.
So he pre heated it with a Propane gas torch, normally used for the soldering bolt etc.

Then started off with the Acetylene and Oxy, started the cut and turned then acetylene off and just cut thru it with the Oxygen only...

I was quite surprised and he told me how it works, and why he leaves the rust there where the cuts going to be, the rust reacts with the heat/Oxygen, creating more heat to keep the cut going.

If you grind the rust off the metal, you have a harder time keeping the cut going.
And quick trick on clean metal is to turn the Oxy down and use the smokey Acetylene flame to deposit a layer of soot onto the metal after you have given it a bit of a preheat.

Doing a search from SMF about gas cutting a few years ago, I found there's actually a setup that adds Iron oxide powder to the gas lines so it comes out of the gas cutting tip when cutting. For real thick metal.

At our local scrapyard they have to cut up steel rods 8 inch's dia, about 15 feet long, into 3 foot lengths, about a 20 foot shipping container full at a time. They get pretty good at it too.

I tend to store my tips in Marvel Mystery Oil when they're not in use. They tend not to plug up as much and are easier to clean that way.

Still not sure about the rig itself. I got a heating tip specially for that make & model. It doesn't work all that well. It just seems like there's a limitation on heat output with a medium duty rig somewhere. Kinda goes along with what Patriot said about buying the best setup that you can afford. I'm thankful for the tool that i do have, but years later wish that i had bought something a little bit better.

Originally Posted by Scrappah

I tend to store my tips in Marvel Mystery Oil when they're not in use. They tend not to plug up as much and are easier to clean that way.

Still not sure about the rig itself. I got a heating tip specially for that make & model. It doesn't work all that well. It just seems like there's a limitation on heat output with a medium duty rig somewhere. Kinda goes along with what Patriot said about buying the best setup that you can afford. I'm thankful for the tool that i do have, but years later wish that i had bought something a little bit better.

That's a new one on me, storing cutting tips in Marvel Oil. I hope that other forum members don't take your advice as Oil and Oxygen go BOOM. They don't mix well.

You may have noticed that your cutting torch is connected to the supply hose's, the red line nut is left hand thread and the green oxygen supply is right hand thread. The fittings are standard SAE and will accept any replacment cutting or brazing torch.

Those combitantion cutting and brazing torches where you just change the brazing tip for the cutting attachment don't work that well get a stand alone cutting torch, and buy one suited to the gas your using ie; acytlen or propane. The stand alone cutting torch can be had in any lenght, I tried one that was 3 ft long and did not like it at all went back my my 18 inch Harris.

Yeah .. definitely clean the tips of ANY oil & clogs before you put them back into use. I usually blow them out with compressed air but a rinse with acetone would work too.

That's a good point on replacing just the cutting torch. I appreciate the advise ... it's not something i had thought of. That might just do the trick !

Maybe after that a propane rig ? The yearly tank lease is 94.00$ A tank of Oxygen and a tank of Acetylene was something like another 87.00$ at the nearby depot where we can exchange empty ones for full ones the last time i checked. It's an expensive tool to own but it's one of those things where if you don't have the tool you can't do the job. Propane would cost a lot less to run and still do the job for most things.