A few tips:
-There are two different pressures on an air plasma system. 1. is the incoming air from your compressor....it should be in the range of about 85 psi to 120 psi....which is the normal range that a compressor cycles. 2. There is the plasma pressure....which is set by the onboard regulator for the plasma system....this is set according to the torch manufacturers specs (should be listed in your operators manual)....and is the pressure that goes to the torch nozzle for cutting. If it is too high you will get rapid consumable wear and possibly misfiring......too low, again the consumables will wear rapidly. Make sure the inlet pressure is staying at at least the minimum input pressure...I recommend installing a gauge right at the inlet fitting to monitor pressure while the air is flowing at the torch. Often the pressure can drop here (if your compressor cannot maintain adequate pressure....or if your inlet hose is too small of diameter or too long).
-If your plasma is a bit underpowered for the material thickness being cut....especially if you have to pierce.....try edge starting and moving very slowly if that is an option. If you must pierce material thicker than the plasma is rated for....tip the torch at an angle (to make the molten metal bounce off at an angle...so consumables are not damaged) and slowly tip the toch up to perpendicular as the arc penetrates deeper. If you simply do not have enough power (amps/killowatts)....then the plasma power source is not large enough fro the job.
-The wire guide standoff device holds the torch at an extended distance from the material. If you remove it and can hold the standoff height at about 1/8" without touching the nozzle (also known as a tip) to the plate....you will have more cutting power. Unfortunately with that torch design...you should not touch the nozzle to the plate like you can with a shielded torch design.
-I'm not completely familiar with your plasma...but if it has different input voltage levels....such as 120 or 240 volt....run it on 240 volts, it will have more available cutting power for thicker material.
-The nozzle in your pictures is definitely trashed. It is fairly normal for the design of your plasma torch to provide consumable life in the range of 30 to 60 minutes...or about 100 to 200 torch starts. Fortunately the nozzles are of a simple design, and are fairly low cost.
With the right plasma and power level you can do that job easily. remember there are plasma torches that are designed to drag directly on the material (for up to 2" cutting at up to 200 amps) and there are a wide range of plasma systems that can easily blow through the material thicknesses you need, and can provide days....not minutes in terms of consumable parts life. Sounds like your system is a bit underpowered for the job.
Jim Colt
