plasma cutting question

Will a plasma cutter cut glass?

Steve

Reply to
SteveB
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Reply to
Michelle P

I have heard tell of people sucessfully cutting none conductive materials with a plasma cutter by first zinc or aluminium spraying the item to make them conductive.

However the huge heat differential from place to place in the material would surely crack glass?

AWEM

Reply to
Andrew Mawson

I think you're right on the heat differential, unless the glass is pretty hot to begin with. It'd also have to be thin, 'cause you have to keep up with the cut on the conductive material.. I think it'd not be worth the effort.

A plasma cutter is the berries for cutting ratchet straps- clamp the strap between two pieces of sheet steel and cut away. Makes a nice, even melted edge on the strap.

John

Reply to
JohnM

Someone else mentioned making a "Sandwich" out of the inner material to be cut by placing it between two pcs. of steel. and clamping it down (I guess light but firm in this instance) I don't know if it works but I'd be interested to hear if it does.

Respects, Rob

Fraser Competition Engines Chicago, IL.

Reply to
RDF

Reply to
mrbonaparte

Reply to
Michelle P

A similar question, different material - will a plasma cutter handle corrugated steel sheet, without having to follow the surface, but rather along a straight line above the surface? Chuck

Reply to
Chuck Jensen

A similar question, different material - will a plasma cutter handle corrugated steel sheet, without having to follow the surface, but rather along a straight line above the surface? Chuck

Reply to
Chuck Jensen

I have cut double sided PCB material. The Epoxy used in the Glass layers really put up a stinky fog. But the Plasma that was using both sides as the ground for the torch - punched right through. I suspect the Impulse through the 2 oz layer (weighs 2 oz's per sq. ft.) About 1.2 mil IIRC. ran the hot ION beam and melted the glass on and then found another ground to run to. It naturally was no stop and was melted easily being another 2 oz layer.

It was G-10 Glass - Not the now Common and approved (non-flammable) FR-4. [ former PCB and ASIC designer ]

Martin

Reply to
lionslair at consolidated dot

Without a ground - I suspect the safety ground was being used that in a round about way made it to the plasma machine.

I was trying to cut some Hot rolled steel - what a pig - the wrinkled (pig) scale on it - really a steel surface - was semi-conductive or highly resistive. I ground off a shiny area and it began to cut. Still not as expected. Mostly a gouge and not a high current burn through. I'll try grinding the back and the front again and pinch the spot with the ground - hope that works.

A surface grinder task if I ever saw one. Create a nice flat conductive surface. Martin

Reply to
lionslair at consolidated dot

Why - Mine follows the surface in my CNC, but the flame won't get to the length needed to reach from one peak to the other trench. In other words if you cut a peak the flame must then cut in the trench from the peak height. The flame (plasma beam) is not a laser, it will fan out and give a different kerf - if it reaches that deep.

Martin

Reply to
lionslair at consolidated dot

No - I've actually been experimenting with this.

If you take concrete (or paving slab, or limestone or marble) and place a sheet of metal (copper is good) about 1/2" above it, then plasma cutting the metal sprays a jet of fine metal spatter downwards, where it will embed in the surface of the "stone" beneath. This is an interesting decorative technique for copper and soft stone.

I also decided to try it with glass. I wasn't trying to _cut_ the glass, just spray it with a bit of spatter and hope it stuck. What I discovered though is that any contact with plasma temperatures shatters the glass immediately. I managed to "dot matrix" print a few dots through copper at some distance, but even this was so unreliable that three or four dots with good cooling between them was as much as I could achieve before shattering the glass. This was the same for window glass, art glasses and even Pyrex.

On a more cheerful note, plasma is also very bad at cutting a leather welding glove stuffed with old sausages! Reassuring to know.

Reply to
Andy Dingley

"Andy Dingley" wrote

I usually keep my old sausage in my pants.

Steve ;-)

Reply to
SteveB

They make a contraption called an exothermic cutting unit which uses magnesium rods and oxygen. This thing uses no electricity while cutting and will cut through anything, even underwater. The navy uses them for cutting holes in flooded compartments on ships. I have used one to cut through a 4" thick safe, because some one forgot the combination .

Reply to
Nate

I used to be a commercial diver. We used (IIRC) Arc-Air hollow electrodes. They were about 3/8" in diameter, a copper alloy, ceramic coated, and had a hollow center. 60 psi over bottom pressure was sent through the hollow center of the torch. It was electric, and we would turn up the amperage to max, 350 if we had a good machine.

It did some awesome cutting, and relatively clean with little slag. It took a bit of getting used to, and worked a lot like keyhole in an open root weld. You didn't want too much of a gap, but you didn't want to stick it through the other side, either, because you would get past what you were trying to cut.

We trained with them in 12 diameter 8' deep tanks. But they did an open air demonstration. They used a railroad rail. The guy was dressed like he was using an oxygen lance, or a burning bar, because that was about what it amounted to.

Stuff flew. People backed up. And in about fifteen seconds, the rail was cut. Underwater was a LOT more tame, as you had the water to catch all the slag and sparks.

We used to do a lot of "wheel jobs" where boats would pick up things in their propellers. Sometimes it was wire rope. That was the easiest. Just get out the torch, find a big bight sticking out, and torch it. You had to do this very carefully because you did not want to scar the shaft, the prop, or the cutlass bearings. And oh, I forgot to say, you were doing this either in muddy shallow water, or in the dark. You didn't want the thing to go sproing and hit you in the head, either.

In open clear water, the barracuda were the most interested. When you started cutting, other fish would clear out. Jakes would swim in to see what was going on. It is an awesome way to cut a lot of metal in a short time.

Steve, ex SurDO2 and HeO2 diver.

Reply to
SteveB

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