Smarter than Bunny Pee

Anyone with animals knows that cleaning up after them is a never ending chore. So, it goes without saying (and yet, I'm saying it) that Sanitation is a major component in maintaining a rabbitry.
Since I'm new to all of this, I have been spending a fair amount of time looking into the various options for cleaning and waste disposal. Now, they've gotten my name and the catalogs have started to arrive. It's rather amusing that you can spend literally thousands of dollars on systems whose sole purpose is getting rid of rabbit poop. I may feature a few of the more interesting methods later.

I don't have any sort of budget allowed for this hobby of mine, so I'm leaning the other direction--the cheaper, the better. Since I'm making my own cages, I'm also making my own litter trays. I can purchase them for about $16 each. Currently, I can make them for $5, and I hope to get that amount down even farther.

Metal pans are out of the question. I don't have the equipment to cut, fold, and weld them. If I did, I'm sure I would injure myself in the process. It would be cheaper to just buy them, anyway.  Making molded plastic trays is also not possible.

So, I've been on a search for a material that is cheap, flexible, and liquid-proof.

My first attempt was to make fused plastic liners for cardboard trays. Fused plastic is lots of fun, the materials are readily accessible, and free. Unfortunately, it's also labor intensive (at least, it is when you're needing more than 20 huge liners), and isn't durable enough. The metal cage wire tears it easily. Back to the drawing board.

Linoleum was my second attempt. I bought a remnant at the hardware store and made 6 trays out of it. One side is water-proof, and I could cut it easily with scissors or an exacto knife. It folded easily and I secured the corners with contact cement and then sealed the seams with silicone. I had to be careful not to get the paper backing wet and they sagged some. Lino is just a little too flexible. But, they cleaned well and would work in a pinch.

The most recent trial seems to be very promising. I purchased sheets of corrugated plastic from an outdoor sign company. The 4'x8' sheets were $30 and I can make 6 trays out of them. It scores and folds just like cardboard, but is rigid and water-proof. I folded them up, used duct tape on the corners and sealed the seams with silicone. No matter what size the cage is, you can make a tray to fit. They are very light weight, but durable. So far, they are cleaning up well. The duct tape makes them a little messy looking, but hey, they're just rabbit toilets. Who said they had to be pretty? If I wanted to get fancy, I could use the contact cement, but I was in a hurry this time.

I'm hoping that I might be able to get some of this material even cheaper, or free, but I might need to be patient. If a sign company makes a boo-boo and can't sell a sign, maybe I can get it for my trays.