what makes plasma cuts smoke?

Every plasma cutter I have used(maybe three different brands) have all had the same type of smoke billow out from under the metal being cut. Except the one I now have. A thermo dynamics PAK master 50. I have made at least a dozen cuts with it, from 14 ga. to 1/2" plate and there is virtually no smoke. This is with the amp control adjusted from barely enough to cut to wide open and nothing causes smoke. This is on carbon steel, stainless, and aluminum. So does anyone know what the smoke is, and why this one doesn't seem to?

Dale Nelson

Often referred to as metal fume. Very fine particles of metal. Most work environment rules require extraction since it is more dangerous than conventional weld smoke. Odd... since all I have used and seen create the smoke.

I have a pak master 75, have had it for fifteen years or so, and have made at least ten thousand times your one dozen cuts- and it smokes every time.
You should see the ceiling of my shop- its brown. And thats with a water table, an electrostatic fume extractor, and full shop air evacuation fans.

You are observing a few odd aberrations. You plasma cutter will smoke. Stuff gets vaporized at 45,000 degrees. Its a physical fact of life.
Aluminum usually puts out big clouds of nasty smoke. Oil on the plate burns. and metal becomes vapor.

I am not saying that plasma doesn't smoke. That has been the case with every cut I have ever made with plasma. But the fact is this one has not made any noticeable smoke in the cuts I have made. I did state I had cut aluminum with it, but I haven't, just talked with someone who said aluminum smokes the worst. Anyway, as long as it lasts, I will enjoy not having to get rid of the smoke!

Dale

If you have any idea of the physics / chemistry behind the basic principals of plasma and its use in cutting metals the question is kinda rhetorical. Google plasma and plasma cutters, there will be more than enough info to answer your question. Metal is being melted and blown out of the cut, some oxidation is taking place as well = smoke.

Not all materials produce the same amount of smoke.....but yes, your PakMaster50 will produce the same amount of smoke as any air plasma with the same power output. Smoke from plasma cutting consists of fine particles of the material you are cutting that are hot, and consequently are lighter than air....so they rise. Some metals and some alloys react differently with the high energy density plasma....and thes ematerials produce larger particles that are heavier than air...so they fall to the bottom of your table instead of rising as smoke. Coatings on the metal (primer, mill scale, paint, oil, galvanizing, etc) will all react differently and produce smoke.

A water table with water relatively close to the plate actually cools these particles (as they are forced into the water) so they sink. A properly designed downdraft table creates enough downward air flow to overcome the energy of the particles that try to rise.....and this flow then either blows the particles outside where they quickly dissipate, or into a filter mechanism where they are trapped. A properly designed downdraft leave not a wisp of smoke in the shop....and allows for better cut quality as compared to a water table.

Oxy-fuel cutting produces similar quantities of smake as compared to the plasma....if you measure the lb's per foot of metal removal. Oxy-fuel cuts a narrower kerf, and at much slower speeds, and lower temperature....so the smoke seems much less evident.

I have both a dowdraft and a water table in my shop. I prefer the downdraft...better cut quality, no fumes, no stains/rust on the material and moving parts of the machine. The water table is simpler and lower cost.

Jim Colt Hypertherm

swellwelder said:

Every plasma cutter I have used(maybe three different brands) have all had the same type of smoke billow out from under the metal being cut. Except the one I now have. A thermo dynamics PAK master 50. I have made at least a dozen cuts with it, from 14 ga. to 1/2" plate and there is virtually no smoke. This is with the amp control adjusted from barely enough to cut to wide open and nothing causes smoke. This is on carbon steel, stainless, and aluminum. So does anyone know what the smoke is, and why this one doesn't seem to?

Dale Nelson

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