In my research, I sourced and obtained a nice sized piece of 3/4" thick PVC plate. I'm considering making a few BCA's (Bucket Cell Adaptors) to try, similar to what Swede did prior to starting this thread so many years ago.
My first thought is to make them round, rather than square the way Swede did, so they'll fit better on many of the bucket lids available to us and offer more space for extra fittings, et cetera, as we develop our systems. I prefer to use titanium round tubes or rods to make my electrode leads to help prevent the salt creep that tends to eat at our copper lead wires.
Thanks to Swede's innovations (see his descriptions in the blog section), I switched to using round CP titanium tubing for my electrode leads which are held in PVDF (Kynar) fittings for a perfect seal which helps solve that problem. The 3/4" thick PVC is machinable, compatible with our chlor-alkali cells and it's fairly easy to use machining taps to add tapered pipe threads through the BCA for plumbing fittings into and out of the bucket cells.
I need to make at least one prototype BCA and try it out in a working cell.
I plan to post photos here of my efforts as I progress. More to come...
WSM 
Recently, I dug out my table saw and the large piece of 3/4" thick grey PVC plate (12" x 48"), and cut four 6" x 6" square pieces. I'm disappointed that they weren't perfectly square (more trapezoidal) but they ought to work anyway, for prototype BCA's.
The practical reason to cut the bucket cell adaptors square rather than round is to avoid wasting the material outside of a circular shape.
My next step will be to use a router to round the edges not facing the bucket lid. The rounded chamfer will help me avoid cutting my hand while handling the hard plastic material, as well as remove confusion as to the orientation of the BCA on the cell lid.
Once I complete the basic shape of the BCA, I need to select a bucket lid to attach it to and then plan the layout. To avoid contamination problems, plus simplify compatibility issues, my thought is to mount the BCA on the underside of the lid, with stainless steel hardware coming through the lid into the BCA. I think 1/4-20 hex bolts with fender washers (all 300 series stainless steel) should work since they'll be outside the cell, with none of it exposed to the corrosive environment inside the cell.
The plan is to cut a hole in the bucket lid smaller than the BCA, leaving a flange for connecting and sealing the two parts into a single, complete unit.
I debated whether or not to use a Viton gasket between the BCA and the bucket lid, but feel the simple solution is to use silicone bathroom caulk between the BCA and bucket lid when screwing them together. The silicone sealer doesn't need to perfectly adhere to all the materials to make a good seal, plus it is easy to remove and replace, if and when needed.
I was originally thinking of using bolts in the four corners of the BCA, but perhaps eight bolts would make a better seal (four corners plus one bolt each between them, on the straight sides).
If I decide I like the plan, I'll have to make a drill guide to keep the hole pattern uniform for matching the hole pattern on the BCA and bucket lid.
More to come...
WSM 
Edited by WSM, 01 May 2022 - 08:27 AM.