Cutting metal with petrol

They're quite impressive. Cut quality is good, even with a beginner using it. Cutting with oxy-acetylene has a tendency to melt its way through, rather than burning, unless you're skilful with it.

Running costs aren't as cheap as oxy-propane though, especially with our petrol costs. Given that most of your cost is for the oxygen, this isn't a big deal anyway.

The main downside to it is that you can't heat metal, and certainly not weld with it. I have a 3-cylinder rig and that allows me to do pretty much anything, just by swapping torch parts around. I buy the propane second-hand, so unless I'm cutting and using a lot of oxygen, I barely notice the gas costs.

The best thing for cutting steel is a plasma cutter, no question. The little one I use can just about sever 1/2" (but not too happily). If I was going to make a habit of it, I'd get a big one, no question.

I use 1" bar, whenever I can find an excuse to ! Thicker is more fun.

This looks cute. Metal cutting with vodka !

-- Do whales have krillfiles ?

Well there's water jet cutting too, which often gives a better finish than lasers, but they're both fixed-machine processes rather than handheld. Plasma (and oxy) can be either.

Our metal-bashers have got a laser, goes up to about 13mm or a bit more, depending on the material.

Gives a very nice finish as you say, but the great thing is that it is really easy to programme, so even complex shapes are not a chore as long as you can describe or draw what you want in the first place.

If you can draw it in CAD, then the drawing information can almost be used as the programme.

Peter

-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info:

What kind of pressure does the water jet have to be to cut steel? Never seen one of these babys working- i imagine its a *very* high pressure, as trying it at 200bar with a pressure washer dont work! ;p

Tim..

My friend Roland was making some replicas in brass which needed to be cut very finely and the water cut steel was very clean edged.

Unfortunately, the company was mortified to find that brass smears around the cut and it cost them a fortune having special jets made that would do the job.

Regards,

Kim Siddorn.

Alternatively you can use rolled hard brass, which doesn't do it.

-- Do whales have krillfiles ?

Lasers, Plasma, and waterjet are very complimentary tools. My knowledge is mostly in waterjets.

The advantage of waterjets is that they can go very thick (like 8" or so, though 2" is more practical). They also have excellent cut quality without heating the part, and can cut almost anything. Lasers and torch cutting are significantly faster, though. Lasers are very expensive. Torch and plasma are relatively cheap, and waterjet is somewhere in-between. They each have their place.

If you find this to be of any interest, you may want to visit

for an overview of the technology. Or specifically:

- lots of pictures

- introduction

- Advantages and disadvantages when compared with plasma, laser, etc.

The above is my web site.

Also see:

(This is where I work. OMAX is the top maker of abrasive waterjet machining centers for the machine shop industry.)

- Carl.

Carl, Thanks for the insight and the links. An amazing product. Unfortunately, a little too expensive for my workshop.

John

They tried all sorts of combinations. It was for the Sutton Hoo shoulder clasps for the new museum and the edges had to be crisp AND the plates capable of being curved afterwards.

Regards,

Kim Siddorn.