Is it possible to cut stainless without heat marks

[mapequipment]

Good morning,

First off let me say I am extremely impressed with the forum alot of great info here, I am new to the cnc plasma world. I actually do not even have a machine yet. I should have a Baileigh PT 44VH table with a Thermadyne A-120 coming in next week. Now to the question, I am already working on trying to get jobs lined up to cut. My cousin came to me with a job he has been having laser cut and wanted to know if I could cut it on the machine without discoloring the metal. It is cutting 28 gauge stainless (not sure of the grade) but the metal has a texture similiar to leather. We have tried it with our hand Thermal Dynamics Pac 100 but it left the dark edge beside the cut. Will this new machine cut it without leaving heat marks? Would I need to use a gas besides air? Will cutting under water help any?
Thanks in advance,
Cody

[jimcolt]

Heat shadows that extend out into the top and bottom surfaces of stainless are there if the proper process power (amperage and nozzle size) is not used...and especially if the cut speed is too slow.

Cut speeds for stainless thinner than about 10 gauge are generally much faster than for steel, and keep in mind that height control on thin stainless is critical as well.

A high definition plasma system (industrial precision plasma cutter) will cut stainless using either F5 (5% hydrogen, 95% nitrogen) or other gas combinations for a clean, weldable edge with no heat shadow whatsoever. These systems are far less expensive than laser systems...and cost less to operate. The laser will hold better tolerances on thin stainless.

Air plasmas that cut thin stainless will cut stainless very well...assuming the machine has the ability to cut at high speeds and to maintain the cut height very accurately. Air cutting will leave a discolored oxidized edge on the stainless....but there generally will not be a heat shadow when operated correctly.

Jim Colt Hypertherm

[mapequipment]

Thanks Jim, very good information. The plasma we have already tried are older and are nothing close to the consistency I should be able to maintain with my new machine. I am sure it will take a little trial and error, but it helps to know that it is a possibility and not just a hope and prayer. Thank you for your time and info it really helps to have somewhere to go to ask questions and not guess my way through everything. I'll let you know how it turns out once I try it. I'm sure I have will have a few more questions in the weeks and months to come.