water table

[pony]

After my new cnc machine arrived I got it assembled, hooked up to my PC, and connected my plasma cutter. I have done a basic test cut in a piece of scrap material. Actually blasting a hole in my workshop floor as the metal was flat on the concrete Luckily it was my wife's name I used as a test cut.
Time to assemble it properly.
I have now built my water table frame (heavy gauge 4x3 tube with 3x3 tubing legs). The frame must weigh close to 400lbs, even though my cut area is only 2x4. I am awaiting a metal nibbler to cut the base of the water table (sheet metal), it should be here tomorrow. I plan to weld the sheet metal base to the water table and add a 1" drain at the same time. I will coat the water bed interior with stove paint to help prevent rust.
I will position the cnc frame 1/2" above my water table frame, that way I can slide a full 4x8 piece of sheet metal in to the work area.
So, what do I use for the work material support? I have seen some fancy fins [?] that people use. I got to thinking, why can't I use regular nails protruding from the bottom of the water (maybe just nailed through a weighted piece of board) to hold my work up and flat. Why do we use metal fins when nails are very inexpensive? Am I missing something?

[jimcolt]

The slats that the metal sits on on a cutting machine are often made from 16 gauge or thicker steel. They last for a long time......the slats on my cnc machine are 3 years old! You rely on the slats to be the work path for the plate you are cutting.....so if you used your nail idea....you woul have to attach a work clamp to the plate for the plasma to operate.

For most...it is less expensive to make the cutting table slats from steel!

Jim

[twicecustom]

Be sure to check that stove paint. Most of it has to be cured at like 400* for 30min. Or it wont harden, then it would just make a mess. Regular paint should be fine, the water isnt going to get too hot for it.

[runninwild400]

Be careful when welding the sheet metal base in. My table sides are made from 2"x6" 1/4" wall and I used 14 ga for the base, after welding the base in using the mig and going as fast as I could so there wouldn't be much heat there my table looked like a banana. I ended up having to run a bead of weld along the top side of the 2"x6" using the stick welder and 3/16" rod then rubbing it with water soaked rags. I managed to get the table back to normal but was way more work than expected, also had to grind off all that weld I put on with stick welder.
My slats are 1/4"x 3" flat and they work great, I load my steel by myself 99% of the time so I'm usually sliding the steel on from one end, any pointy surfaces and your steel will get badly scratched when sliding across it, with the heavier slats they seem to last longer before getting marked up much, plus when they get in bad shape I just flip them over.
Good luck with the rest of the table build

[pony]

Some very good feedback.
Thanks guys.

[pony]

runninwild400, I guess I didn't fully appreciate the extent of the problems you faced; I'm new to welding, having only taught myself to weld two years ago. No formal training, no guidance (except YouTube vidoes) and just a 'consumer grade' Hobart 185 amp MIG welder. All my experience to date had been welding schedule 40, or materials of similar thickness. A very forgiving material for a novice.
Major nightmare in making the water table! My frame went together like a dream. When welding my 14 gauge base to the rather thick frame I experienced identical problems to the ones you described. The base is not at all smooth. I had no idea the heat would distort it so badly.

I finally managed to get it somewhat level. However my welding skills are not sufficient to be able to create a nice continuos smooth bead between the 1/4" and 14 gauge material. The table leaks in a number of places. I went back and tried adding another bead on the inside edge of the table, but fear I made it worse I blew through the material in a number of places and ended up making some pretty embarrassing patches. I described it to my wife as leaking like a sieve, its not that bad really but sure hurt my pride in explaining why I wasn't as excited about the table she said looked amazing.
The way I see it I have two options:
1 - drop in a thicker piece of sheet metal and re-weld a new base. Buy a thicker sheet that matches my current skill set.
2 - line the base with high temp metal filler, fiber glass, or similar 'false' skin.

I did my first real cut using the assembled table today (sans water). I'm pretty excited so far. I have to tune the table after its initial assemble, but I have a piece of metal I cut myself...

[ronsii]

Hey Pony, just jbweld the leaks or even silicone would probably last a year before it needed attention...

[pony]

Hey Pony, just jbweld the leaks

Perfect. I didn't know the name of a product that would hide my shameful welding . I found a few repair options (Lab Metal), but JB Weld looks like it will do the job. It also means I can say I welded the base to the frame (well JB Weld-ed it ).

[pony]

I bought a large can of Bondo fiberglass today.
I'm going to line the whole of the inside of the water table with it. I'm not going so far as to paint it
It appeared to be the cheapest option. I'm not sure of the longevity.

[RJ Fab]

When I built my water table I just placed the pan on the bottom and stitch welded it to the frame from the outside. Then I ran a nice bead of caulk on the inside. It's been done with water in it for 6 months and no leaks so far. I figued once the caulk goes bad it won't take much to clean it up and apply a fresh bead.

I also started out using 1/4" for my slats. I ended up not liking how thick they are because of what leatherhans stated above. I took the 1/4" slats, cleaned them up, and welded on some channel brackets that were bent like an "s" shape that allows for 14g slats to slide down into the top open part of the "s". The 14g works much better for me.

1 more thing. Look into the plasmaquech recipe that can be found under the search here. I had my table with water for just 2 months without it and it went down hill quick. Now that the plasmaquench has been added it's been 4 months and everything looks great.

Good luck,

Luke

[NDN Tom]

When I built a water table, I noticed 2 things... Small parts ALWAYS fell into the tank, and then in murky water, I could hand search through 239 pieces of scrap to find my part... Usually number 186 was the part..... The other thing I observed was the plasma "dust" hit the water and bounced right back off of it virtually solving nothing... The water did splatter on the bottom side of my plate, and lightly rusted that quickly... (great).... I enclosed the table with light sheet metal and a few bingi cords... one side has an opening just big enough for a squirrel cage blower output.... The squirrel cage blower just sits under the table, and with a coffee can guard on the motor and its pulley...stuff just falls on it and falls off... Now I can find my small parts by sliding the side plate outta the way and going under the table... that minimizes the handling of 185 useless drops, buried in very cold rusty mud, elbow deep.... Suck the dust with a fan, or lay on your table, elbow deep in icy water and fish for the correct part, thats now wet and muddy.... That choice was pretty easy for me after this brief experiment, a wet arm..and ANOTHER wrong part fished from the deep, with grates leaving impressions in my ribs.... Do that 100 times and I bet you will get a $7 squirrel cage fan at a garage sale, and make sliding panels to skirt the table. I bet you get the right part on the first try...

[Metal Lee]

I use a water table and it works good, I just use a $7 magnet on a teliscopic handle and catch the part before it hit's the water and if by chance I miss the part I know where it hit the water so I just stick the magnet in the water to get the part or just cut another part if it is that small it won't stay on the table it's not that expensive to just cut another one.
It works good for me as i cannot blow my dust outside I live in a built up area and the people next door have a pool and hot tub outside. The water table reduces my plasma dust by at least 75%.

[isthmus]

Nothing needs more constant maintenance than these darn tables. Glad I found this site. Every one of these suggestion outstrips my jerry-rigged solutions.