Here is how I used to apply.  Get DuPont Duco cement and thin about 25% with some acetone to make it brushable.  Brush a medium coat on your frame and then dry.  Stretch your silkspan over the frame and brush through it with some acetone to reactivate the cement.  Hold and it will dry quickly.  Follow up with thinned clear dope.

You can apply the silkspan damp this way.  Then it will really dry smooth but watch for warps.  You can steam those out.

BTW, this can be a real challenge but fun project.  And the finish can be beautiful.  Even more fun when you use colored silkspan rather than painting.  If you can't find the color you need, you can color the white by dampening it with some water with food coloring.  You could do a tan or green top and light blue underbelly this way and then just paint or decal on insignia and the shark's mouth.  Finish out with just enough thinned clear dope to seal.

Tom