DIY Acrylic tank question

[cokemanj]

I'm really thinking of building a 75g acrylic and I've got a question about the curved front corners. I really like the way they look, but I haven't been able to find any info on how best to put the bottom on one that has curved fronts. Is it just a matter of bending the front piece and then marking off where to cut the bottom one? I don't really want to risk making a short or jagged cut. I also don't think I want to just keep the bottom straight and have a "lip" on the bottom. Is there maybe some trick or better way of doing this or should I just stick to a regular design?

[tropicfishman]

all you have to do is get the front piece the way you want it, set on top the bottom piece and use a sharpie to make a nice line around the curve of the tank. Then fire up your jig saw and cut along the line

[cokemanj]

So then if I cut the corners off, do I just kind of sand down the cut to try and make it a closer match to the bends or does acrylic cut fairly smoothly?

[redswi]

the best tool for cutting acryilc is a router ...it will give you the cleanest cut

[2cvbloke]

I just spotted this thread and I'm intreguid by this...

How thick does acrylic have to be to make a decent sized tank?

Now I'm not saying that I want to build a whale tank like Scotty did in Star Trek IV (6inch thick sheets needed there!!!), I'm just considering building a tank myself rather than getting a pre-built or custom-made tank at they're expensive here...

[jsoong]

I wouldn't suggest jigsawing to a scribed line ....too easy to end up with jagged edges, and if you are a bit off, you end up with a poor bond.

I would bend the front to the shape you want, then glue up the sides on top of an oversized bottom piece. After all is set, trim off the excess at the bottom using a router & a template bit (using the actual walls of the tank as your template). Acrylic cuts like hard maple, and need sharp tools. Even then, you will leave tool marks. You can finish the edge by flame polishing or sanding.

Bending of acrylic is tricky .... You need to heat the acrylic so it is pliable & bend it with a form .... too much heat & the acrylic burns and leave ugly brown marks, too little & it cracks when you try to bend. The pros do it in an oven with controlled temp, but we'll have to settle for blow torch or heating wires. When I built my overflow, the first few bends were all burnt (but since it is out of sight, the brown marks didn't matter.) I was only bending maybe 6-8" long pieces, longer bends may be even trickier. I used a propane torch for the heating, maybe heating wires would be more controllable?

BTW, if you are doing 90 degree bends, the acrylics will form dimples at the edges right where the bend is. You will need to sand that flush before bonding.