Water table fluid

What additive are you guys using for your water in your water table?


A few tablespoons of Sodium Nitrite powder works really well to prevent rust on the slats and whatever material you are cutting. We have also found that borax powder works well too- the benefit of borax powder is that you can buy it at home depot.


Or at the supermarket in the detergent aisle :slight_smile:

Anyone else remember the old western TV shows with the “20 Mule Team” sponsor? I think Reagan was in it :smile:


This is a recipe from another plasma cutting forum, I have no experience with it but would be curious to find out if anyone else has.

Here’s the recipe for home-made PlasmaQuench
1/4 pound of sodium nitrite powder ($15/pound) “anti-rust additive” NOTE: nitrite NOT nitrate!
1 teaspoon of Physan 20 ($8/8oz bottle) “antibacterial/antifungal additive”
1 oz Ultramarine blue food-grade dye ($5/oz.) “color added so folks won’t drink out of it!”
Mix well, treats 75 gallons of water.
All prices include tax and/or shipping.


We have tested this recipe and it works well.


What’s the actual fluid volume of the water table assuming its filled to the minimum distance to the top of the slats?

Their formula suggests that 1/4lb (4oz) of Sodium Nitrite would treat 75 gallons so that around .05oz per gallon. I lack the chemistry background to know if that is a valid way to scale the formula and if there is a point at which the solution would be to strong if under diluted.

What’s a good source for the Sodium Nitrite in reasonable quantities? It’s on Amazon but as you can imagine it is not a big seller there so feedback on the quality of the product being offered is minimal.

We typically put about 5 gallons into the water table. The maximum capacity is ~8 gallons.


I’ve been using the boraxo (sodium carbonate) for the last week or so. Mixed in a 5 gallon bucket and used pool test strips to get the Ph above 9.0. No rust occurring and the parts coming off aren’t flash rusting right away.
Drained and let the bottom debris dry up today, broke it up with the vacuum brush and refilled with the same water.


I just ordered some Green Cut Plasma fluid. Here is the info on the fluid: https://www.lubecorp.com/greencut-plasma-cnc-plasma-cutting/

Per the calculator, you will need .5gal (2 liters) to mix with water.

I called my local Lube Corp distributors (Airgas, etc) and no one stocks the green cut and had a minimum order of 6liters.

This place stocks the Green Cut fluid in PA with no minimum and shipped me 2 quarts (for some reason they sell by quart not liter) for $48. Very friendly and highly recommend: http://www.jonesracingproducts.com/


Boraxo is a brand name of a hand soap that has borax [sodium borate] in it. Borax is NOT sodium carbonate. [baking soda] So i just wanted to check what actual mixture you were using. thanks.

Hi. Yes, Boraxo washing soap is sodium borate. No, baking soda is not sodium carbonate. Arm N Hammer washing soda is, while ANH baking soda is Sodium Bicarbonate.

Borate or carbonate is used as a softener or Ph increase of course which the Ph range above 8.5 I believe is where rust is inhibited. Lower than that and it is an alkaline and will likely make it worse as well as attack the base metal aluminum.

I am using Arm N Hammer washing soda and pool ph test strips to set my mixture near 9.0 Ph. Don’t really have measured value, but it’s a couple of handfuls to a 5 gallon bucket and a half.

Best, Steve.


I have friends in the table industry who are manufacturers, users and field service. The tables water is routinely check for balance and adjusted often. Also understand that what we’re doing here is much smaller and the potential for bacteria growth is something not to be overlooked. Be conscious of what your touching bare handed and breathing in, whether it be water table or open cutting. I’ve learned a bunch on this forum from you guys as well as a few other forums and plan to utilize PPE where necessary.



Definitely. Although the water table will trap a lot of the typical particulates that come from plasma cutting, it’s worth using a respirator. I use one that fits under my faceshield. It’s especially important if you do galvanized metals. I wear shaded glasses when doing quick work and the face shield & respirator when monitoring a long job.

Your face isn’t right in the work the way it is with welding but if you spend a lot of time cutting at the machine you don’t want to get the shakes.

Here’s the respirator I use.
Miller Electric ML00895 Half Mask Respirator, M/L, Single Filter https://www.amazon.com/dp/B00WIH1OVM/ref=cm_sw_r_cp_apa_t0mWBb9QZTWM4


Thanks James, I have followed your lead on many things discussed here, much appreciated.

Completely strange idea here, but has anyone ever considered using subzero windshield washer fluid. obviously water based and can sit in the garage here in Chicago area through the -10 degree days? just got my unit and am almost done setting it up. Lots of ideas here, just looking for the best option in my region… thanks

You have to check to see what they use to lower the freezing point and check if it’s arc-safe. Alcohol for instance might not work well as the arc boils it off :wink:

If there’s an antifreeze used in it then it needs to be a non-flammable type. Regular car antifreeze for instance is going to be very bad. The RV potable water stuff is okay though.

Remember you’re hitting that water with an arc at 25-50,000 degrees :open_mouth:

I’ve read here in another post that rv some antifreeze is flammable. Just looking for options because of temps here.

Not the kind that’s for “potable water” - you can drink it :slight_smile: Most people don’t do that but if you have residue in the plumbing lines it won’t kill you or make you sick.

what was your amount of mix using the 5 gallons to get your levels good

Hi. Seems to be less than a cup. I use the Arm N Hammer washing soda, add it to the water until test strips about 9.0ph. I’ve never really been exact with the water level. Probably around 6.5 - 7 gallons I figure. I did buy the Green fluid and am just as happy with it as the soda.

1 Like