But it turns out that was just a part of the work I was doing to it.
I wanted to add an outboard tank for the water/quench mix that normally sits under the cutting slats.
I’ve got a couple reasons for wanting to do this.
One-evaporative losses on the roughly 5’x10’ table turn out to be considerable. And while that in and of itself isn’t a problem as you just add water to fill it back up-my issue was that the design of this table doesn’t allow that water to flow through the table and therefore I end up with areas that don’t mix with the quench chemicals that are also anticorrosive and so end up with rusty spots.
I purposely didn’t order an air bladder equipped machine because we cut a lot of aluminum, and there is a potential for the hydrogen that is off-gassed when cutting aluminum and when it’s in a water solution to accumulate and then go boom.
But I wanted a way to rapidly drain the table for clean out, adjust the water level for different cut operations, and to filter the water in hopes of extending or eliminating the sludge clean out intervals associated with water table plasma cutters.
I should elaborate here that for CNC plasma or oxy-fuel tables, there are two typical ways of dealing with the smoke, particulates, and nasty crap that comes off of the metal as it’s cut: a downdraft and air filter system; or a water table. Both systems have their pros and cons, but in the end the purpose of them both is to control and contain the hazardous to breathe crap that is produced.
So to start with, I sourced a big 125 gallon poly rv water tank. I cut a large access hole in the top for air/hydrogen to escape and to allow access to the submersible pumps I would put inside. There is one large high volume pump with 1 1/4” plumbing to fill the table rapidly, and a smaller pump to circulate the water mix in the poly tank and run it through a filter.
Here’s how the first version of all that looked.
This setup used the single factory-supplied water table drain with a T to a manual ball valve to drain the table or seal off the drain, and a pool check valve to keep the water table from draining back into the poly tank on the other side of the T.
Several issues were immediately apparent with this setup.
First, high volume water shot up and made a big mess from the single drain/fill point when filling the table.
Second, due to the table/slat design, this alone wasn’t going to be enough to help the table circulate the water adequately enough to do any amount of self-cleaning.
Third, the pool check valve didn’t work for shit and allowed the water table to drain back pretty quickly.
So a little back to the drawing board.
I then decided to add more drain/fill points to the water table to promote self cleaning, water flow across the table, and stop the geyser of water from the single drain/fill point.
That required adding some holes.
No worries-just punching a bunch of 2” holes in a brand new 55 thousand dollar machine. 😄😄😬
After making quick work of the holes with the Milwaukee cordless knock out, I cut some 2” threaded nipples and welded them in.
They got welded inside and out, then I ground and blended the inside welds for better drainage.
Next, I had to build a big threaded pipe manifold to connect all the drain/fill holes together.
2” galvanized pipe fittings have gotten ridiculously expensive. 😬😬
Then the whole contraption had to be installed under the table, where I used strut and clamps to hold it, and flexible line to connect it to the fill/drain points.
Once it was all connected, and a new and improved check valve installed, it was time to test to make sure there were no leaks before moving to the next step.
No leaks, and the new check valve was working!
Woo!
Next stop-addressing clean out and flow across the table issues.