Will a Krylon Matte Finish spray can work?

I would decant it (put a straw to the Krylon tip and spray the contents into a smaller container, using only what you need and saving the rest in its original container) , then use it from an airbrush unthinned.

-Jeff

What kind of paint is it and what kind of paint are you wanting to clear coat with it?
If it is lacquer based and your model is acrylic or enamel you run the risk of wrinkling the paint underneath the clear as it goes on the model fairly heavy from a spray can. If it is acrylic then it might work fine but I would test it on a scrap piece with the same paint on it as you used on the model.

Mike