CNC Plasma / Water Table Design




Introduction: CNC Plasma / Water Table Design

The issues we had with our CNC plasma table were health concerns, smoke, debris, parts dropping to the ground, a messy environment, etc. I scoured the internet and found two promising designs; a CNC plasma air table design and a CNC water table design. I joined an internet group on Facebook called CNC Plasma tips, tricks, and sharing that is an extremely helpful and friendly group. I found a design created by Mike G that inspired us tremendously. We created notes, communicated with each-other and finished our project within one week. We hope this will help you skip some headache, time, and troubleshooting. Enjoy!!!

Step 1: Research and Development / Direct Materials Cost

Our team ( James Lee and John DuCrest ) had discussions, took notes and created a cost list. We presented the idea to the owner of Special FX Lighting, Beth Lock. Beth approved the cost and build and our team got to work. The following is a quick overview of our teams Cost List, Parts List and Added Weight.

Direct materials cost:
Approximately $508.64.

Our Parts List:

  • 12' x 6' 12G hot rolled steel - $311.54* / 315 lbs
  • 20' U-Channel - $63.92* / 80 lbs
  • Sodium Nitrite (NOT Sodium Nitrate) - $15.00*
  • Physan 20 - $8.00*
  • Blue Green Dye - $10.00*
  • Plumbing / pneumatic supplies / nuts, bolts, odds and ends - $100.00*
  • Two 55 Gallon Water Barrels - Reclaimed / free

Added Weight to the table:
1,095 Lbs ( This includes the weight of the water when the table reaches capacity ).

*We chose not to give our exact cost of materials because cost's may vary depending on a number of circumstances. I hope this will provide a good idea of what a build like this may cost.

Step 2: Sizing

I used a plasma torch to cut 1" off our 12' x 6' hot rolled steel to make it fit our table correctly. We used our 20' U-Channel as a cutting guide and clamped it down. We lined up the plasma torch against the U-Channel and it gave us a nice clean cut, fitting our table perfectly.

Step 3: Drain 1

We chose a suitable spot for our drain and cut a 4" x 12" section with a plasma torch, I used a right angle as a guide. We saved the piece we cut out for later use.

Step 4: Drain 2

We set the dimensions of the drain to 4"x10"x12". I designed and cut out a 10" x 32" piece of 16G mild steel on our CNC Plasma Table and after some calculation we found the best way to bend our mild steel.

Step 5: Drain 3

James used a break and bent three right angles to make a 4"x12"x10" tall metal sleeve.

Step 6: Drain 4

James used the piece of metal I cut out from the "Drain 1 step" as the base for the drain. James welded the seams on the inside and outside of the drain. We tested the drain for leaks and by filling it with water, drying it off, and placing it on a clean section of the hot rolled steel. We waited for 10 or so minutes and found a couple small leaks, James patched them up with weld and we repeated the water test. It passed the second time.

Step 7: Drain 5

James cut a hole and welded a 1.25" black coupling to the bottom of the drain.

Step 8: Drain 6

James welded the drain from the top side of the hot rolled steel.

Step 9: Drain 7

We flipped the hot rolled steelover and welded the bottom side of the drain.

Step 10: Installing the U-Channel

James cut the 20' U-Channel to fit the 12' length of our CNC Plasma Table. James welded it to the middle of the frame, length wise. This gave us support for the added weight of the water and kept the hot rolled steel level. James took the remaining 8' of U-Channel, cut it in half and set it aside to be used later for added support.

Step 11: Powder Coating, Welding, and Sealing

Barry Cobb, Kyle Lallis and Shane Slater Ethan LeBaron and Caden Fitzgerald from FX Powder Coating applied the powder coat our hot rolled steeland installed it on the CNC Plasma Table frame. James drilled holes on the edges of the hot rolled steel and filled the holes with weld to secure it to the CNC Plasma Table frame. James used CRL Silicone Sealant Cat. No. 33S to make the table water tight. There are many different options of sealant available, we chose this because it was on hand. James carefully applied the sealant to the top and bottom edges of the table and every gap he could find, including the bolts. There were 4 large gaps on the corners of the table, James cut 30 mil plastic pieces to fit into the large gaps and liberally applied Sealant to that area. When the sealant dried we replaced the grate.

Step 12: Bracing the Center of the Table

I took one of the 4' sections of U-Channel and traced two patterns of the interior dimension onto 10G steel. I cut out the 10G steel feet with a 3/8" Dia. circle in the center with a plasma torch. I welded the 10G steel feet to the bottom of U-Channel. I welded a 7/16" nut to the top of the steel feet ( height adjuster ) and screwed in the 7/16" bolt. This gave us the ability to fine tune the height of the bracers. James welded the bracers to the U-Channel 45" in on each side.

Step 13: Leveling the Table

The eight legs associated with our CNC Plasma Table are all right angles. We decided to design and cut out eight 3" x 3" 10G steel feet with a 1/2" in diameter circle in the center. I welded the steel feet to the interior base of each leg. I screwed a nut to the 7/16" bolt about 1/4" and placed it into the 1/2" diameter circle. I welded the nut/bolt combonation to each steel foot. With the turn of a wrench we now have the ability to fine tune the angle of the table.

Step 14: Water and Air Distribution Parts List

James took two 55 gallon water storage drums and strapped them to a pallet, James and Eric Chamberlain discussed the best places to install our plumbing to our water distribution system. Our parts list is as follows:

  1. Two 55 gallon water storage drums
  2. 1 pallet
  3. Two metal straps
  4. Two 2x4's
  5. 10' of 1.25" PVC pipe for water distribution
  6. Four 1.25" 90 degree elbows for water distribution
  7. Two 2" male thread to female slip for water distribution ( the bottom parts attached to the barrel )
  8. Two 2" x 1.25" bushing for water distribution ( this attaches to the 2" male thread to female slip)
  9. One 1.25" Tee for water distribution ( this connects to the bottom right barrel)
  10. One 1.25" PVC Union for water distribution ( this allows us to unhook our barrel's from our drain )
  11. One 1.25" male thread to female slip for water distribution (Attached PVC to Drain)
  12. 10' of 0.75" PVC Pipe for air distribution
  13. Two 0.75" male thread female slip for air distribution ( these connect to the top of the barrel )
  14. Two 0.75" 90 degree elbows for air distribution
  15. 1.75" Tee for air distribution
  16. 0.5" female thread to 0.75" female slip for air distribution ( attaches to the 0.5" nipple )
  17. 0.5" nipple for air distribution ( which attaches to the 0.5" ball valve )
  18. 0.5" ball valve for air distribution ( which attaches to the 0.5" x 0.25" busing )
  19. 0.5" x 0.25" bushing for air distribution ( which attaches to a 0.25" nipple )
  20. 0.25" nipple for air distribution ( which attaches to the air regulator )
  21. Air regulator for air distribution ( which attaches to a quick connect)
  22. Quick Connect for air distribution

James took teflon tape and wrapped all threaded fittings for both water and air.

James used a primer and cement Christy's red hot blue glue on all PVC slip fittings.

Step 15: Water Distribution 1

James took our pallet (2) and positioned our water storage drums (1) on it. James took our two 2x4's (4), cut them to length and screwed them onto the edge of the pallet to help stabilize the water storage drums (1). James took our metal straps (3) and secured the drums to the pallet.

Step 16: Water Distribution 2

Our water storage drums have two inlets, we used the bottom inlet for water distribution and the top inlet for air distribution. Different water storage drums may have different configurations so you may have to improvise. In this section we will discuss assembly of the water distribution.

  • James took our 10' 1.25" PVC pipe (5) and cut it to appropriate lengths.
  • James took our two 2" male thread to female slip (7) and attached them to the bottom inlet of each barrel.
  • James took our two 2" x 1.25" bushing (8) and attached them to the bottom inlet of each barrel.

  • James took one of our 1.25" 90 degree elbows (6) and attached it to the 2" male thread to female slip (7) on the water barrel pictured left.
  • James took our 1.25" Tee (9) and attached it to the 2" male thread to female slip (7) on the water barrel pictured right.
  • James directed our PVC pipe to line up with our drain. He used the remaining three 1.25" 90 degree elbows (6) to get us their.
  • James took our 1.25" PVC Union (10) and attached it between to the top left 1.25" 90 degree elbows (6) and the 1.25" PVC pipe (5). This allows us to easily remove the water storage unit from the table if the need arises.
  • James finished off our water distribution by attaching our 1.25" male thread to female slip (11) to the drain and connecting it to our 1.25" PVC pipe (5).

Step 17: Air Distribution 1

In this section we will discuss assembly of the air distribution.

  • James used our 10' 0.75" PVC pipe (12) and cut it to appropriate lengths
  • James took our two 0.75" male thread female slip (13) and attached them to the top inlet of each barrel.
  • James attached our two 0.75" 90 degree elbow's to each of our 0.75" male thread female slip, he then ran our precut 0.75" PVC pipe (12) and joined them together with our 0.75" Tee (15)
  • James took our cut 0.75" PVC pipe (12) and ran it to the back of the barrels
  • James connected our 0.5" female thread to 0.75" female slip (16) to the open end of the cut 0.75" PVC pipe (12)
  • James attached our 0.5" nipple (17) to the 0.5" female thread (16)
  • James connected our 0.5" ball valve (18) to our 0.5" nipple (17)
  • James attached our 0.5" x 0.25" busing (19) to our 0.5" ball valve (18)
  • James connected our 0.25" nipple (20) to our 0.5" x 0.25" busing (19)
  • Our air regulator (21) attaches to our quick connect (22). The quick connect is attached to an 80 - 120 PSI air hose. We adjusted our air regulator between 5 - 10 PSI. We found that to be plenty of air pressure to expel the water up and through the water distribution system to fill our table.

To empty the table, we disconnect the air supply and simply open up the 0.5" ball valve (18) and watch the water drain back into the tanks.

Step 18: Plasma Table Water Treatment

Water treatment will reduce corrosion and improve safety‎. You can purchase it from a manufacturer however after doing some research and price comparisons we decided to make our own.

I purchased Sodium Nitrite ( not Sodium Nitrate ), Physon 20 and Blue Food-Grade Dye. I found the formula on two separate forums. There did not seem to be any negative feedback from this formula and so far it has worked for our table. The formula was designed for 75 gallons of water:

  • Sodium Nitrite: 1/4 Lbs
  • Physon 20: 1 teaspoon
  • Blue Food-Grade Dye: 1 ounce

At capacity, our table holds 88 gallons. We decided the base formula would work even though we are 13 gallons over. I converted the formula to grams and used a scale to divvy out the different chemicals as follows:

  • Sodium Nitrite: 133 Grams
  • Physon 20: 30 Grams
  • Blue Food-Grade Dye: 28 Grams

I used a gallon paint can and filled it 3/4 of the way with hot water. I added our measured chemicals to the hot water. I used a pneumatic drill with a mixer and blended the chemicals until our chemical substance was mixed thoroughly. With the CNC Plasma Table empty, we pressurized our water distribution system to 5 PSI and slowly flooded the table with water. While the table was filling I gradually added the chemical substance as the table filled up. We then drained the table and our mixing was complete.

Step 19: Video 1

Our first test of the build.

Step 20: Video 2

Testing the water, one of us was a little too excited :D

Step 21: Video 3

We addressed the health concerns, smoke, debris, parts dropping to the ground. We are still working on making sure the area stays as clean as possible, but we are making quick progress. I hope you have enjoyed this Instructable as much as we enjoyed building our water table design and sharing it with you.

This could not be possible without the generous support from James Lee, Kyle Lallis, Eric Chamberlain and Wil DuCrest of Special FX Lighting. Shane Slater, Ethan LeBaron, Barry Cobb and Caden Fitzgerald of FX Powder Coating, SlyScience, the CNC plasma tips, tricks, and sharing Facebook group and Mike G ( Mike if this finds you I want you to know all of us here admire your work ethic, and have nothing but respect for your design skills ) you are all AMAZING!!!

Thank you!!!

1 Person Made This Project!


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8 Discussions

Shaina weldher
Shaina weldher

Question 7 months ago

Can you please share the slat info please? Thank you!


2 years ago

do you have any pictures of your slat design? i saw one picture, but wondered how the rest was set up.

Kenneth Cantrell
Kenneth Cantrell

3 years ago

Awesome design and execution! I never cease to be amazed by the brilliance of the creators on this site.

John DuCrest
John DuCrest

Reply 3 years ago

Everything I have learned about computer science, engineering, basically everything I know has come from sites like this. This is my way of giving back, I hope I continue sharing what I build, what I learn and what I enjoy with the community that has given me so much. Thanks to Instructables for giving people a chance to share with others. And thank you Kenneth for your post.


3 years ago

Great improvement, but there i see some problem, i have CNC plasma cutter to and smoke extract fan, then plasma cuts steel, the melted steel go out and fallig down, steel become cold and in you case when you fill out water, then the small steel pieces will go to water tank and stays there, after some time mall steel pieces fill the water tank and clog the hoses, other disadvantage - is lot off rust in the water, but the health is at first place ;)

John DuCrest
John DuCrest

Reply 3 years ago

We have plans to place a small, removable grate above our drain. We do most of our cutting on the other end of the drain so the majority of the melted substrate collects there. Our water distribution pipe uses 1 1/4" PVP pipe which should not clog. And we have the ability to disconnect our entire water distribution system from the table. As far as the rust is concerned we are hopeful our water treatment solution will work. If it does not, we will address that issue and work towards solving it.
Thank you for your comment.


3 years ago

Amazing skills, you guys must be a great team to work with
You got a link to your business?

John DuCrest
John DuCrest

Reply 3 years ago

Thank you, it was defiantly a group effort. My SlyScience website needs updating, if you need to contact me you can find me here or at