I have had this project on hold since summer, finally have time to get around to it.
I picked up a bunch of stainless to make these signs, it is warping something awful while cutting, if I had THC like the Pro has it would be more fun. Monitoring the warping while the torch runs and keeping the plate down as it goes is a nail biter but I got through two of them so far, 10 more to go.
I think I will try making 2 tool paths and let things cool down in between. I also will pick up a couple more gallons of RV antifreeze and get the level of the water table up some.
Any other ideas are welcome.
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You definitely have the warping going on. I cut 18g steel and it tends to warp also but my water level is almost to the top of my slats so I would think that should help some but I don’t know how slow you have to cut that stainless.
Maybe clamp a piece of angle from end to end where you know it won’t interfere and make several cut paths like you mentioned and move the angle to keep it out of the way but keep it flat while cutting?
Good luck
316 stainless steel has a linear expansion coefficient of 16, steel ranges from 10.8 to 12.5 so warpage is going to happen more with stainless vs. carbon steel. it should return to shape after cutting. try cutting at the fastest speed you can and still get an acceptable finish. 
if you cant stop the warpage you can try heating the warped parts and rapidly cooling them with a wet rag to shrink it back. similar to shrinking body panels with a torch and rag.
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Thanks man, I will take the warp out of these panels, it just makes them hard to cut. Now that I have these two cut I will determine if I want to use cold rolled steel or this stainless for the rest of the signs. Over all they are coming out very well. When I get them powdered coated and in the field they should look great.
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Why are you using antifreeze? Is that stuff safe under UV light that the plasma produces?
Onto your question
Stainless is pretty much guaranteed to warp, just need to minimize it. A few things I did to help:
Large blocks of aluminum or copper as weights. Keep the plate down and soak up some of the heat.
Stop every few cuts and let the post flow help cool.
Cut hot and fast and close nozzle height
Also sometimes now if I do fine detailed cuts, I submerge the stainless plate. I run just straight water also.
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Might want to do a handful and let it cool down in between cuts.
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if you are using powder coat as a finish, why waste the $$$ on stainless steel?
Only because someone had a bunch of it for sale cheap on craigslist last summer. I have all I need for this project with plenty left over. My thought was if I could buy this stuff cheap, why not use stainless , now the warping…
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Whats with all the golf balls?
So that the customers have something to hit the signs with.
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Water level looks low.
You change the pause between cuts to enhance cool down and see possible tip ups.
Use clamps .
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Set up a water mister that runs with the torch cooling direct area
I have the same problem with anything under 12 Guage. I run 11-12g around 125ipm at 40 amps on my Miller 625. I changed out the 50mm slats on my table to 1.5 inch 11 G pieces so I can partly submerge some pieces that want to warp.
But I can run mild 10 or 11 Guage steel at 150-160 ipm all day with no issues at all!
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Will the pro table actually follow that curve?
I have no idea, it would be interesting to watch it try.
It should follow that no problem if the THC is anywhere near as good as the cheap one that I have…
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It will follow that no problem. The maximum Z speed when during THC control is 60ipm. So if your torch speed is 60ipm, then it would be able to climb at a 45 degree angle without colliding with the plate.
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Interesting. I guess I didn’t even know what the THC did. I thought it just made it so you didn’t have to loosen the jam nut and drop the torch down onto the shim before starting a cut. I guess I ordered something fancier than I thought I was supposed to be getting 
Will it cut corrugated metal then?
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