Hi all,
Weld on #13 does make a fairly strong bond between PVC and acrylic, but it will craze extruded material, it is messy and because it is mostly solvent it makes a ton of bubbles when the solvent evaporates away. Generally, I hate the stuff. It really only works well when you have extremely small gaps to fill (less than 1/16").
Anyway...
Super Glue makes a new adhesive called "plastic fusion". It is actually acrylic monomer and a peroxide catalyst. It is packaged like epoxy and located near the epoxy in my local Lowes.
It smells just like weld on #40, but it is a much thicker (almost pasty) material and cures much faster than #40.
I have only used it once, but it seems to work quite well. I would rough up the parts with a bit of sandpaper to make sure it gets a good grip, but the cured material is hard and strong and is acrylic. The only real drawback I can see is that it is pale yellow in color, but for the upsides, I can live with it.
Adam