In the constant quest for more and better tools, I've been looking for a larger and better Electrolysis Tank (E-Tank). I had been using a 55 gallon Rubbermaid trash barrel, but I found that the cylinder shape was not very efficient. It is great for long skinny parts, but it will only do 1 cultivator at a time. I looked at rectangular tanks on the 'net but they are pricey. A 50 gallon tank, 36"L x 18"W x 18"H, is about $190 + shipping. So I kept searching and found a reasonable tank at Wal-mart.
- 45 Gallon Sterlite Plastic Storage Bin
I was wandering through Wal-mart and found a 45 Gallon Sterlite Plastic Storage Bin that looked like it might do the job. I paid the $15 and carted my new E-Tank home. After I decided where to put it, I filled it with water. (As an aside, there are several reasons that tin cans are round and not rectangular. A cylinder will use less material than a cube for the same volume. In addition, using the same material a cylinder is stronger than a cube.) Yep, after it was full of 45 gallons of water, my lovely rectangular tank had deformed into an ugly circular tank. The solution was to reinforce the sides to prevent them from bowing out and creating a circular tank. I had some aluminum extrusions left over after scrapping some jalousie windows. The frame is made up of 4 pieces of the extrusion with a couple of pieces of 1/4-20 allthread holding the side pieces tight against the end pieces. Great! But how to hold this frame in place? Putting screws through the sidewalls of the tank is self-defeating because we both know that they will leak. What about using suspenders?
- E-Tank Suspenders AKA Hot Rails
If the frame is suspended, it has to hang from something. More extrusions to the rescue. I reinforced the top edge of the tank using some 1/2" aluminum strip and angle. The strip and angle sandwich the plastic edge and give it additional strength. It also gives me a place to hang the main frame. Here is a picture of the E-Tank all tricked out. You can see the "suspenders" that carry the main frame as well as "Hot Rail" reinforcement.
I call these reinforcements "Hot Rails" because they are hooked to the positive side of the battery charger. If these rails are briged with something that conducts electricity, then both rails are hot as well as the piece that connects them. Hmmm... This means that the sacrificial electrodes don't have to be hard-wired to the tank which makes them a lot easier to clean. To remove the electrodes, just lift the supporting bar and carry them away to be cleaned. I use 3/32" stainless steel welding rod, bent into an "S" hook. Having the Hot rails also means that the electrode plates can be located anywhere in the tank. We know that the electrolytic action is stronger when the plates are close to the part. For odd-shaped things like cultivators, arrange the electrodes in a "V" to get close to both the pointy end and the shank. Here is a detail shot of the Hot Rail on the tank.
But what about suspending the part we want cleaned up?
- Mk.2 Fiberglass Part Support
If the part support bridges the Hot Rails it has to be non-conductive. A conductive support will short the battery charger and ruin an otherwise nice day. The Mk.1 part support is a piece of 2"x4" with the part wired on to it. It works, but is so inelegant. What else can we use that non-conductive and sufficiently strong? How 'bout fiberglass? It is strong, stiff, can be machined, and it is non-conductive. The Mk.2 Part Support is a fiberglass pole 1" in diameter, 20" long, and has hioles drilled in it every 3". I got the pole from the feed store. Look for electric fence posts. I have found lightweight posts a 1/2" in diameter and this 1" diameter big boy. The post, as purchased, comes with the holes pre-drilled and is 5' long. I whipped out the handy-dandy Sawz-All and created 3 Mk.2 Part Support posts. At this point the fiberglass rod really isn't a significant improvement over a piece of 2"x4" lumber. But if we could make these rods conductive for part of their length, then we could use the same stainless steel "S" hooks that are used to suspend the electrodes. I took some .040" stainless steel safety wire and laid it along the length of the fiberglass. Using more of this safety wire, I threaded some pieces through the existing holes in the fiberglass, snagged the parallel wires and tightened up. Now the fiberglass rod is conductive over the length of the parallel wires. The "S" hooks now are in contact with the one of the parallel wires when the part is hanging in the tank. Here is a detail shot of a portion of the Mk.2 Part Support showing the fiberglass rod, the parallel wires, an "S" hook, and the safety wire used to bind the parallel wires to the rod.
There you have it, total cost of materials, for me, was about $20. The tank is about 18" x 18" x 32" and can hold 3 cultivators at a time. Using the Hot Rails and the fiberglass part supports, I can change the setup in the E-Tank in less than 5 minutes and don't need to keep replacing the hangers for either the electrodes or parts. Maintenance is greatly simplified because the electrodes are not hard-wired to the positive side of the battery charger. With fewer wires strung out everywhere, the chance of mishap is also reduced. I hope this gives you some ideas about setting up your own cheap E-Tank.
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