you can silicone sheets of rock together that are bigger than the mouth of grown species. I did this with my whites. Just do it in a plastic bag, after a couple hours u should be able to flip them over to let other side dry. Cure for 48 hours. Make sure u find silicone that's shrink, heat, and crack proof. That way they're more flexible. Also just rinse them good, just in case there's any residue.