Water Treatment is mainly use for Water Tables in CNC Plasma Cutting. Check out our comparison of CNC Water Table vs Downdraft Table Page.
The use of a water table in CNC plasma serves a few purposes. The idea is to use the water to keep the material cool during the cut process, which helps to reduce warping and distortion in thin or highly detailed pieces. The water also is used to capture the smoke and dust created from the plasma cutting process. But using water does comes with some challenges. Water can go stagnant and cause rusting problems with the metal you’re cutting. Thus comes water treatment. The goal of water treatment is to prevent rusting both in the table and on the metal we are cutting, and to prevent the water from turning into a science project and growing things like algae since its a stagnant body of water.
When I started out I began researching and trying various products. The products I tried were:
- Plain water
- Plasma Quench Home Brew
- GreenCut Plasma Fluid
Plain water
For me this was a complete disaster, Rusting started on the slats immediately and and spread to the sheets rapidly during cutting. The table also grew algae and after a week of heavy cutting was just a mess. Draining and cleaning the table were also the most difficult with plain water. The metal dust formed hard plates of slag that were difficult to remove and adhered to the slats and bottom of the water pan.
Plasma Quench Home Brew
This is very similar to Plasma Quench but you purchase and mix a few chemicals. If your really interested you can look up various recipes but the chemicals involved are; Sodium Nitrite, Physan 20 and sometimes a color dye. The experience with the home brew was about the same as with the commercial brand and after research the use of Sodium Nitrite and Physan 20 after high heat and uv exposure with atomization is not good for humans. Sodium Nitrite MSDS, Physan 20 MSDS.
GreenCut Plasma Fluid
In my quest and research I had not found the perfect product yet and stumbled upon GreenCut. GreenCut is made by Lube Corp, a Canadian company. GreenCut was advertised as a product specifically designed for plasma cutting and it was People Safe and Environmentally safe. The CEO is even on video drinking the product to prove his point. I would never drink it, but I know that doing that with any of the other products would be fatal. GreenCut is designed to prevent Corrosion, Prevent Bacteria, it has an anti-foam component and does not degrade due to thermal or UV. GreenCut is designed so that if the concentration is properly maintained, you never need to change it out and can use circulation pumps and filters to keep the fluid going indefinitely. Sounds Great right? Well, does it work? Yep, it sure does. I was hooked and used it for years in my second table with great results. We use it for our in-house Titan Series X Plasma Table.
Using GreenCut
GreenCut is designed to be mixed at a 20:1 Ratio (20 parts Water to 1 part Green cut) You can use the GreenCut Calculator to determine how much you need for your table. From years of using the product, I would recommend starting off at a 15 to 1 ratio. I found better performance with this ratio. Preperation is important. To get the best results with GreenCut, your table needs to be perfectly clean. No rust or debris and new clean slats, not rusty old slats to start. Your initial mix needs to be accurate, and you need to get your mix ratio correct. After your first mix with a clean table, Use some simple PH strips or electronic ph meter to test the concentration. Make note of the ph level so you can refer back to it. As the water evaporates and you use the plasma table, you will need to add more water and monitor the PH level.
Circulation Pumps & Cleaning
For best results, your plasma table should have circulation pumps. These can be simple swamp cooler or pond pumps to keep the mixture even and consistent across the table. Most people clean their plasma table out once a year. This yearly clean out involved draining the table, cleaning out the table, and putting in new slats. Then putting in a fresh batch of GreenCut. Some people also do small monthly clean outs, simply scooping out debris and drops. One neat thing I noticed with GreenCut is that instead of there being a dust, which welded itself to everything like other products, the dust formed balls, like little bb’s, with GreenCut. It was much easier to clean out the table. And GreenCut has never burned my skin or caused any irritation.
I have never had any problems with GreenCut affecting any metals, copper, aluminum, steel, or stainless. I also have not had any problems with secondary processes like paint and powder coat. After a part is cut on the table, I use a pump garden sprayer to rinse the piece over the table, so there was no waste or runoff, then I dry the piece. I did not scrub it or need to use any additional prep. The pieces also did not have any problems with flash rust after this and would last a few weeks in moderate humidity without any problems.
My Experience
I’m located in AZ where we have extreme summer temps of 120+ and my evaporation rate is high. I added water daily and checked my PH weekly. I ran a slightly higher concentration of GreenCut just because I was adding water on such a regular basis to my table.
Cost is a major factor for most people and I get it. GreenCut is likely the most expensive option out there and the best option in my opinion. When doing business, I look at my costs and the risk, benefit, gain, gain loss on the investment. I look at GreenCut as a once a year cost and a cost of doing business. It breaks down to a few pennies per piece, or less, depending on volume of your plasma table. The less you use your plasma table, the longer it lasts The more you use your table, the less it costs per piece. The biggest reason for using GreenCut for me is health and safety. It does not matter if this a hobby or a full time business, your health should be a primary concern. Many of the products out there are so bad for you. Just read the MSDS on these things and most were never intended to be used for Plasma.
