El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

Cheers, yeah I was thinking of adding holes to allow a bar to help tighten it up.

So my wife gave birth to a happy little baby boy last weekend, which has as you may have guessed been consuming most of my play time! I haven't been able to do any milling but I have made a slow start on my anodising setup. I did a lot of reading up over the past week or two about LCD anodising method, and I've decided that the first thing I want to tackle is the anodising tank itself.

I bought a large polypropylene crate (just look for a number 5 and the letters PP) at homebase, which is big enough to fit the largest pieces I want to anodise at a little over 600mm long.

Problem is that I couldn't find anything with the length or depth required in a narrow width, so the crate is about 80L, probably 60 or so when filled to a level that I require. That's a lot of sulphuric acid, even if it is very dilute when using the LCD method. Seems that the recommended concentration for 6 ASF (amps per square foot) is 1:15, so I will need 3-4 litres of sulphuric acid to mix with 60 or so litres of water. It's also going to be very heavy, so my plan is to build a wheeled wooden frame around this crate to support it and make it easier to move around. There are definitely some logistics to consider with this much acid around and I may end up storing the solution in some appropriate plastic drums when not in use to keep things a bit safer.

To help keep the solution cool and with the happy side effect of displacing some volume from the tank thus reducing the amount of acid required I have made a PVC pipe system that I can pump cold water through to help keep the temperature down. Made using 32mm pipe and chemical welding






Next up will be the cathode bus bar and cathodes. From my reading Aluminium cathodes are better than lead in several regards, and means I don't need to worry about eventually disposing of lead contaminated solution.... but it seems the type of aluminium is quite specific for the best results. 6063-T6 is the specific type recommend, and I managed to find some fairly large extrusion in that formulation.

So far I have just cut up the pieces, the angle extrusion will be bolted to the square bus bar using stainless steel bolts (will be above the solution, not in it).

I am also considering my options for agitation. Easy one is air bubbling, but I've seen a few using acid-proof pumps to move the solution around which seems like a better option and would give me a mechanism for pumping the acid out into drums for storage and vice versa.

Anyone who has any experience with anodising I'm always up for helpful info given I'm a noob.