Polycast is imperial thickness, so 3/4" = 0.750". It's Plexiglas-G that is metric, or 3/4" = 0.708" so take that into account.
If your OD requirement is 96 x 32 x 23.5 then your ends are going to be 2 * thickness smaller, so if 0.750" thick, ends will be 30.5 x 22 pieces, f/b will be 96.25 x 22, top/bot 96.25 x 32.25.
The added 0.25 is for allowing the fillet to form and to allow for flush trimming. The ends are actual dimensions since they are bonded on all 4 sides. The 0.25 can be 3/8", 1/2", or more, as long as you have enough to work with to allow for the fillet.
Squaring of the ends is important. These 2 pieces really need to be square, but more importantly, they need to be the same. It's a bit tough with 3/4" thick to double-stick tape those together and run them through the router to make them identical, but at worst they should have one corner squared off then they can be separated as long as each pass is done to both pieces back-to-back with the same settings.
Then for the front/back, you will pass these through such that both are the same height, and the same height as that same dim on the ends. So your final pass would be all 4 pieces with the same fence setting on the router. Tricky when you have 96" long pieces I imagine, maybe James/Acrylics can give you advice on that, I haven't made a tank that large.
top/bottom can be rough cut, you're going to trim off all 4 edges anyways.
For pins, get a hold of some stainless steel wire that dentists use for braces. Tough stuff, can handle the weight of the panels.
For solvent, I would try to DIY some. WO #4 isn't really that great, MC with 5% glacial AA and you're good for sure.
Should not need WO40 beads. James has stated in this thread that he solvent welds up to 2" thick panels, and then there's the whole WO40 vs solvent weld strength debate (short version: correctly done solvent welds win)
Question: laminate bit?
I build odds and ends for my aquarium such as algae clips. the label just says acrylic...
