To Drain or Not to Drain my Water Table

[DesertFabworks]

I was going to build my water table with a drain and a sump system but now that I have the pan built I really dont know if I want to drill holes in it and go to the trouble of building a sump system.

If you have a water table what do you do and why? Do you drain to stop evaporation? Can I skip the drain and just pump it out every once in a while to clean then pump it back? If you were in my shoes what would you do?

[garyroushkolb]

I just kept mine simple and put a drain in it but in 6 months or so I haven't drained it. I just add to the water level when it's down and burn away. This works for me but I don't use it every day. There has been times that I have felt like draining it to find something small that fell through the slats and I couldn't find but i usually just cut another one. Fishing between the slats will cut the back of your hands in the worst way so invest in a good magnet on a stick.

[toddler]

Our table came with a drain from the factory, and we have drained it a time or two to clean it out in the last several years. Over time, alot of slag and junk, as well as small pieces from holes etc. build up under the slats. We had to pull the slats out and shovel the slag out. It's amazing how much weight those little balls of slag add up to. It is definitely alot handier to clean out if the water is drained. But i don't know, it may be just as simple to get some kind of pump, and pump it out the top too, as long as you're just pumping your water, and not slag, as it could possibly be hard on your pump.

[jmsrbrt]

I've got my water table connected to two 55 gallon drums. Open a valve under the table, and the water goes to the drums. Pressurize the drums and the water returns to the table. I've got a few kinks to work out, but by doing this, I save a lot of water from evaporation, and I can find and remove those small parts and sludge.

[toddler]

sounds like a good plan. how do you pressurize the drums? with air?

[jmsrbrt]

I have an air line going to both barrels, then "T" 'ing where I can hook up a hose. A little bit of pressure, and the water leaves the barrels and enters my table. Closing a valve underneath the table, keeps the water level up, opening the valve drains the water back into the barrels. Drains a little slow, but right now the compressed air in the barrels can only escape from the 1/4 inch air line. I plan on adding another valve perhaps where I can let the air escape faster.

[Dawgonhawg]

Jmsrbrt, do the barrels have to be below the table to drain? Are the barrels vertical or laying down?

Thanks, Dawg

[redfarm]

PLEASE, DO NOT use drums in this way....yes I know many have including me but.....If possible go to your local scrapyard and see if they will sell you the tanks that they get in from all the cheapo' air compressors. tanks good/compressor dead our local yard gets a bunch of these in. I bought two of them. I mounted the air dryer on one and mounted the other before the plaz.I believe they are around 30 gal. each and they usually have at least 1 large pipe opening.If it doesn't have to drain all the way You could make the "blaadder"type integral to the pan and use air to control the level....that presents issues of it's own as well.

[muzza]

I had the pleasure of draining and cleaning my water tray this evening . I normally do it every 6 to 8 weeks but this time I went an extra week making this 9 weeks of buildup. I have a 2 inch ball valve fitted via a nipple welded to the underside which is 1 1/2 inch internally, you can see the drain in the top right corner of this pic.


As you can see there is a bit of a build up of metal dust in the slurry left behind which is about 1/2 inch deep and takes a bit of elbow grease to scrape off. Here in this pic you can get a better idea of the buildup at the drain. This pic is after it's been draining about half an hour.


Note the color is wrong in this pic due to use of flash, it is actually jet black and takes some scrubbing to get off your hands and clothes, yes I had gloves but unfortunately punctured them pulling out the slats.

After picking out all the scraps of metal I ended up with half a 20 litre tub (about 6 US gallons) of sludge which I just leave to dry out and then dispose of in the rubbish. There's probably half as much again that goes out with the water.

So in answer to your question, I'd say yes, you will need a drain. If you are going to drain to a tank you will need to be able to access inside the tank for cleaning too as all this crap will end up inside your tank.

Murray

[jmsrbrt]

Jmsrbrt, do the barrels have to be below the table to drain? Are the barrels vertical or laying down?

Thanks, Dawg

They are below the table. Water drains by gravity.

[DesertFabworks]

Jmsbrt: Can you include some pics of your system and the pipe system?

I'm getting ready to plumb my system. I have gone back and forth on using the pressure system like you or using a pump. How much psi does it take to move the liquid to the table?

I have included some pics of the cart I made to hold my drums.

I've got my water table connected to two 55 gallon drums. Open a valve under the table, and the water goes to the drums. Pressurize the drums and the water returns to the table. I've got a few kinks to work out, but by doing this, I save a lot of water from evaporation, and I can find and remove those small parts and sludge.

[jmsrbrt]

Pictures as promised. These are steel drums with I believe a 2" hole in the bottom, and a 1" hole in the top. On the bottom, I came out with a valve and union so I can remove one or both barrels if needed. There is also a valve under the table so I can close and retain the water in the tray, rather than depend upon the air pressure in the barrels. Also a "T" in the line with a hose bibb if I just wanted to drain everything. At the top 1" hole is where I used reducing fittings to get my air line connected. It takes about 2-5 psi I'm guessing, to pressurize the barrels and move the water up to the table. The air lines go to a "T" fitting where I connect my air. Right now I drain the table by opening the valve under the table, and removing the core in the air fitting. It's a slow process since the air within the barrels has only a 1/4 inch opening to vent. I plan on doing something different there to make it go faster.

[DesertFabworks]

Here is what I came up for the table. I put two 3/4 drains in the table one on each side. The drain tubes run down to an individual drum one for left and one for right. I have a valve at the table and at the drum so that I can shut things off and multiple locations and do maintanice.

The top ports on the drums are connected togeather and are my vent. I ran them over to one side where my air regulator and air connection is. I put multiple shut offs on this section as well.

I filled the pan with a hose and checked the pan for leaks. I was happy to find no leaks in the pan.

I then opened up the drains and allowed the table to drain into the drums. It was a little slow since my outlets for the drums are joined into one 1/2 pipe exit. It took about 15 minutes for the table to drain the 70-80 gallons the table was holding.

Some may say that's way too slow but I dont think it will be that bad. I can open up the drains and work on a few other things while it drains. I dont expect to be draining everyday. More likely it will be for cleaning and maybe when I shut down for the weekend during the summers to limit evaporation.

My drain bungs in the pan were set in 3/16 above the bottom of the table. I did this in an effort to limit the gunk that flows down the drain. I hope and expect to have most of the junk in the water to settle to the bottom and not flow down the drain. I have screen filters in line to limit junk going into the drums.

Since there is that 3/16 step the table does not empty every last drop. I sucked out the last of the water with a shop vac to see how much it would leave. It was only about 8 gallons which is not bad and I can live with that. I expect to use a shop vac when I clean it out anyways.

When it came time to pressurize the drums and send the water back up I had a regulator on the line but not a pressure gauge. I added a pressure gauge so I could watch the pressure later. I found that I did not need anymore than 5-10 psi to move the water back up to the table.

It took about 10 minutes to move the water into the table still not a big deal for me. I can start the fill while I turn on the computer and get other things set.

All in all it worked out pretty well.

I have attached a few pictures. I have everything out for powder coating and expect to go live in a few weeks for some actual cutting.