I know of no 'hobby' grade adhesion promoter. You can run by any Car Quest auto parts store. They have same stuff i use, but in an aerosal can. The stuff from the can has a bit different formula, and isn't quite as consistent but over all does the trick.

This is a link to the cleaner I use...

http://semproducts.com/Catalog.asp?prod=79

and a link to the ahesion promoter...

http://semproducts.com/Catalog.asp?prod=146

If any of you guys are looking for a splash of this stuff to go through your airbrush I can hook up with some.

Adam