Plasma cutter sputters

[Phil9N3667]

We have a Thermal Dynamics, model Cutmaster 82 plasma cutter at work. I was using it this week and it started misbehaving, not keeping a flame, burned the tip hole out to about 1/8. Changed the tip, no better. Found the ground clamp fasteners were loose, tightened them up and it helped a little bit. It would start the arc for a few seconds
and quit. Adjusted air pressure up/down, no difference. When turning it off, back on now, I don't hear a clunk inside when air pressure comes and no air comes out of the tip. Anyone here have any ideas on what to look for??!! Thanks.

 

[Janicholson]

Wet air is the most common issue with radical nozzle wear. It also can and does affect solenoids and valving systems. We run Hypertherm and Miller Plasma and both suppliers are very careful to tell us about H2O. We use a refrigerated dryer on our 15hp compressor. We were shown tips that lasted minutes with 40% relative moisture air. If the gas you use is dry I have no clue. Jim

 

[Steve in VA]

X2

 

[300jk]

We have a 2 Hypertherms at work. What Jim said about moisture. We also have the rebuild kits for the gun. Includes more than just tips. Maybe your problem could be the parts behind the tip ? Just a thought.

 

[grizz02]

Mine has a water filter on the back , also I always grind a clean spot on the metal for the ground to attach

 

[504]

Take your gun apart again,if you did not get it back together just so so it will not do anything. Look for white residue on the consumables. I have had mine quit (Cut Master 45)and all I need to do was take a tip cleaner to the air holes and it has worked fine since. If you have a filter change it,if you don t buy one.

 

[RM-MN]

Check the fuse box to be sure you have full voltage. If I trip one half of the breaker so I get 110 volts instead of 220 that the plasma torch requires I get your symptoms.

 

[deanostoybox]

If the metal you are trying to cut is magnetized it will act like it has wet air. Also the magnetic flux can draw the molten metal back together bridging the kerf behind the arc.

 

[Janicholson]

Molten steel is non magnetic. Not a flame, it is just a bit of physics. Jim

 

[Phil9N3667]

Thanks, guys. I'll look at it when I get a chance this week.

 

[rlp in Co.]

Are you sure about that? I have tried to weld next to a magnet that I use to hold parts together. I sure messes up the molten weld!

 

[Steve in VA]

Molten metal such as iron and nickel will not be magnetic in and of themselves. The randomized orientation of the atoms means that no net magnetism exists. However, if exposed to an external field then the atoms will react. Above a critical temperature, the Curie point, a metal will lose its magnetic property due to the randomness.

Nonetheless, the weld puddle will react to the presence of an external magnetic field. Even though individual atoms are random, statistically more can be oriented opposite from the others and so a weak magnetic force will present

Also, the arc is the result of current flow between the electrode and the base metal so again an external magnetic field can affect its track.

At least, this is my understanding and I hope it helps. No guarantee written nor implied. Offer not valid in all 50 states. Some settling may occur during transport.