What are plasma cutters?

[rmjsugwas]

Hi all,

sorry for asking this but could someone explain the difference between plasma cutters and oxy acetylene.
i have an oxy acetylene set and was wandering if plasam cutters were any better/ easyer to use? - never come accross them before.
keep it simple please!

 

[Wozzaaah]

Oxy acetylene uses a gas flame whereas plasma cutters use an electric arc and a compressed air stream.
Here's a little video of one being used.

 

[rmjsugwas]

thanks for the video wozzaaah,
so what sort of steel thickness can they cut....does it have to be 'new clean steel',
do they cope with rust?

 

[Shox Dr]

The biggest difference is a Plasma will cut Stainless and Aluminium.

I have a 50amp unit and it will happily cut 1/2-5/8 steel and 3/8 Ali. If pushed I have cut 7/8 steel

 

[rtbcomp]

They'll cut copper and rusty metal too.

 

[astro_al]

They can also cut painted / treated metal.

A realistic maximum cut without spending a real fortune would be around 1.5", more if you don't mind cleaning some mess.

Nice things to have around & no gas rental.

Al.

 

[Wozzaaah]

As long as you can ground the earth properly and get the arc started they'll cut pretty much any old metal to it's capacity. That one is the one I have, bought from our very own Weldequip. It's rated to cut 10mm I believe but that leaves the edge a little rough so needs a quick going over with a grinder.
Thinner stuff, even up to 8mm is a breeze.
As has been said, no cylinder rental, just plug them in, hook up an air supply, attach the earth clamp, place the torch over the workpiece, press the trigger and you're away.

 

[rtbcomp]

Only those with a pilot arc will strike on painted metal.

On mine if the cutting arc fails the pilot has 3 or 4 goes at restarting it, which is great for cutting mesh.

 

[shenion]

Only those with a pilot arc will strike on painted metal.

Mine does not have a pilot arc (trafimet type) and will start on anything.

 

[rmjsugwas]

so what sort of money buys a good second hand unit?
i have 3 phase.
what goes wrong with them and what consumables do they have?

 

[chunkolini]

2nd hand? start at around £400 for a reasonable machine, comnsumables the tip and shroud die after a while, before buyinng one check that you can get spares, there squillions of versions, no standardisation here.

I wondered about buying one for ages, went to the local tech college cheekily asking one of the tutors if I could have a look. He demoed it and Kerching!! sold. I just had to get one. Fantastic pieces of kit, if you have a use for them.

Oxy/acetylene is a pain on thin steel, a plasma gives a real clean edge that almost needs no dressing once you have got the hang of it.

try and get a go on one, but wait until you have the funds, it hurts like hell when you get a desire for things you cant afford.

Note, I had to be ****** to order mine, skint but in lust with it.

Where in the Uk are you? I sure somebody on this forum will give you a play. I am in Herefordshire.

Hope that helps, Chunko'.

 

[Robotstar5]

On mine if the cutting arc fails the pilot has 3 or 4 goes at restarting it, which is great for cutting mesh.

The one at work actually has a "mesh" setting, gives continuous pilot