You "could" use it - but it is different.
The powders that are designed for use with turps have a binder in solid state that gets activated by the turps to make the powders stick where your stuck them. If you use the medium instead (and I would suggest skipping the overpriced GW medium and pick a bottle up at an art store - or use Future) you will need to mix it with the powders first in order to get good penetration and apply them as a paste.
Of course, the paste application changes pretty much everything in the use of powders.
Not sure what the problem is with turps though, it is fairly safe. Don't drink it of course, but you probably have a lot more dangerous stuff under your kitchen sink or in your garage. If you don't like the smell - you can get odorless turps which will work the part as well.
Barring all of that - you can also shop around a bit. Bragdon uses a pressure sensitive adhesive (you sort of stab at it with your brush and it sticks in place). No need to use anything to stick it in place.
|