To all you CNC plasma users. What fluid do you add to your water table, if any? I’ve seen a couple of recipes, mainly from the USA, and of course there are the proprietary fluids. Interested to hear your thoughts. Thanks.
I will be the first to reply, I use washing soda, but then again I am not a professional plasma shop and not needing to account for all the health and safety hoops.
I am not sure if I am allowed to post about another forum that is pure CNC plasma, which you already may know they tend to either use the green stuff or again soda.
The issue is that the effects of high temp plasma hitting the water and vaporising it is unknown. BUT a lot will depend upon the design of the plasma table and where the water tray is in relation to the cutting face. The best solution appears to be that the cutting is 3 or 4 inches above the water tray, a lower LEV system can be used and the water tray catches most of the dross in the water.
With no water tray one gets everything blown around by 60 to 70 psi air so it can quickly go in the atmosphere you breath, which is bad. One then needs very high throughput LEV systems.
If you have the parts either touching the water level or not much above the water level then it can greatly reduce air born particulates, clean things up a lot, but you get more dross on the back of the metal due to the cooling effects of water/liquid.
So the 3 or 4 inch gap in between seems to be a best compromise from dross build up and large LEV systems as the water does do a lot of the filtering. Also the 3 or 4 inch gap means that the plasma arc is not hitting the water and causing the instant vaporising of the water/liquid/green stuff/soda so the chemicals within it are not being released.
Long response, sorry, bet you only wanted a quick answer.
Adrian, I really appreciate your long response because it answers many questions I had yet to think about. What concentration of soda do you use? Thanks.
https://plasmaspider.com/viewtopic.php?f=3&t=24254 This is about use of green stuff and soda, worth a read the general consensus was enough to keep a high level it seems to prevent fungus growth, must admit I have not had that issue on mine and also acts as an anti-corruption agent although how i do not know.
https://plasmaspider.com/viewtopic.php?f=103&t=22101 This is about a water table depth/height sorry saying the best separation is closer to 6 or 7 inches.. Again have a read. i just checked the rules and do not think I am breaking any!
Jim Colt who frequents the site is some sort of guru with Hypertherm plasma.