Water table drain adapter and plug

With RH threads for both the nut and the sacrificial zinc plug, tightening the plug loosens the fitting in the table. I suppose I could loctite the nut, and that would probably cure it. I hope to drain the table when not in use to make the table easier to push around the shop. The brass plug weeps if I don’t put a little torque on it.

I could also plumb a valve for this purpose. If I do that, does the zinc electrode need to protrude up into the main water bath? Or would it be ok if it was threaded into a T under the table? Would doing that reduce its effectiveness at preventing galvanic corrosion above, or would it still work as long as the water is in contact with it?

I bet it would make the brass fitting more expensive, but if there was a hex machined on the bottom of the brass drain adapter, it could be used to counterhold while tightening/loosening the plug. If the zinc needs to protrude up into the water table, I’ll probably do something like that.

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The zinc anode only needs to have contact with the water and also have electrical continuity with the aluminum water tray. So as long as the t-fitting is metallic, it will work fine.

Applying loctite to the hex nut would definetely help with removing the drain plug.


Thanks for the quick reply! I guess I’ll plumb a T and a valve, and post a pic back here FWIW.

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@rswarner mind posting some pics up when you’re done?

Here it is. It was about $40 at the Big Box store. It’s kludgey for sure, but it will work. And I did check to ensure good continuity across all that Teflon tape. I considered sweating the nipple and reducer into the table fitting with solder, but the Teflon was easier and works fine.

The parts are all 1/4 and 3/8 pipe. The electrode leg of the T is a 1 1/2” nipple with a 3/8 FIP to 1/4 FIP reducer on the end.


I dont think that looks kludged together at all, nice job. And good thinking about checking the continuity :+1:


Nice solution. I’m going to do the same so I can drain it easily into a bucket so I can easily move the table when I’m not going to use it for a bit. The bucket will also help reduce evaporation.


Very nice! I’m digging it!

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Until it got dirty, corroded, or otherwise lost connectivity with the table the anode would still do its job if it was just thrown into the fluid wouldn’t it?

So with that, wouldn’t the anode still work if it was just tethered to the water table by a copper/steel wire and just sitting somewhere in the fluid? The wire is only really necessary to avoid the potential for losing connectivity due to corrosion or build up on the surfaces of the anode or the table. That could be done by just adding a small self tapping screw to one of the rolled edges. Doing that would remove a majority of the plumbing required to have it threaded into the adapter.

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Yes Ed you are correct. Many anodes will have a copper wire in order to maintain electrical continuity with whatever material the anode is tasked with protecting. If you simply placed a bar of zinc in the bottom of the water table, electrical continuity would be lost over time.

I was puzzling over how to mount it in the plumbing so it was visible. It’s nice to be able to see that it’s intact. In that sense, the stock configuration is really nice, if you don’t want to frequently drain through that port. A second port for draining would probably be the nicest solution, but I’m off to the races and pretty happy about it!

What size thread is the brass fitting going into the water table itself where the plug goes? (ie Water Table plug tread size) I would like to get those parts before my table arrives. Thanks! Great idea!

Hi Tony,

The plug has a 1/4" NPT female thread.

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Hey got a question on this .not planning on draining mine my plan is frequent use but minimal heat in my shop can I use an additional additive to stop it from freezing like an RV antifreeze?

I had just posted on another topic about water level and such, thought better to remove and post here. After dialing in my table, I notice the one corner is slightly low which I expect since I leveled the tray first then the rails. I put a weld-less bung (7$ Amazon) and ball valve near that area and left the anode in place.


Yeah, all things equal, two ports seems like the best set up. Now to find a 7-or-so gallon container to put the water in! A 5gallon bucket isn’t quite enough :face_with_symbols_over_mouth::crazy_face:


Maybe someone with more plasma experience could comment on any downside to glycol in the water. It makes sense to me, but IDK what the downside(s) might be.

See this plasmaspider thread:

I have a friend who’s a service tech for plasma tables and another who is an prominent manufacturer. The automotive coolant is flammable and poisonous. Not to be confused with what we are doing here. I think the green dye is confusing to most.

More water related stuff. Might seem hokey but this silicone funnel has been on my optical tracer for a bit and now this machine. A cheap little shield to keep the sparks down and the splashing water. You can find them in 4 packs on Amazon for pretty cheap. For high amperage cuts 1/4"+ I roll it up a bit. May load a video clip to IG.