I have Model Master (custom enamel system) gloss clear lacquer finish.

I want to use it with an airbrush. It is to thick for direct airbrushing an therefore i want to use Humbrol enamel thinner to thin it.

Does this sound ok???

Other question; can I apply this lacquer finish also on the transparent parts of a canopy or is this going to create troubles??

Hi Drabslab. Ive never used model master glass cote, but I have used their flat cote, and it was with Humbrols enamel thinner, I thinned it with. So there should be no problems there.
I dont think a gloss cote on a canopy (or clear parts) will be a problem ... but Id go to the aeroscale forum for that answer. Most here, deal with flat cotes for finishing.

MM gloss lacquer finish is, if it is labeled correctly, not an enamel. It is a lacquer which should be thinned with lacquer thinner. It contains solvents that attack plastic if not applied carefully and may craze the clear canopy parts. The common practice is to use Johnson's Future floor finish. It's available at your Walmart or supermarket where the house-keeping supplies are shelved and is dirt-cheap.
Future is a very thin acrylic which brushes or airbrushes without the need for reducers and leaves a very glossy, resilient finish. Transparent canopies can also be dipped, being held by the frame edge with tweezers and set aside to dry. Future is frequently used as a topcoat before decaling and weathering, and sometimes after as well. Microscale Microcoat Gloss has similar properties but is more expensive oz. for oz. A final coat of a flattening agent such as MM Dullcote (another lacquer) or Microscale Micro Coat Flat (an acrylic) will kill the gloss. Just be sure to apply the flat finish before attaching the canopy.

Here is a link to a lengthy treatise on Future. It addresses absolutely everything one could wish to know about its hobby uses.

http://www.swannysmodels.com/TheCompleteFuture.html