http://www.tapplastics.com/plastics/...ves/index.html
I use Tapp Acrylic Cement its thinner than water and you use a syringe to apply it. You have your edges clamped together and it is sucked in by capillary action.
I would suggest reading these 2 articles by linear on building an acrylic case.
http://www.bit-tech.net/article/67/
http://www.bit-tech.net/article/72/
peace.
unloaded