Gelcoat filler

[mikenda - delete]

Advise please on gelcoat filler,
A) How do I prevent the mix from “sagging” when working on a vertical surface?
B) How does one make White a shade of Magnolia?
C) What is the best material for sealing the filler from air whilst curing?

 

[30boat]

I have used poliester topcoat mixed with coloidal silica.It won't sag but it has to be very well mixed to avoid lumps.It doesn't need to be protected from the air but it will have to be abraded or degreased before applying another coat.

 

[charles_reed]

Tape a piece of stiff plastic film over the gelcoat until it is dried.

Frequently, if you get the fill volume just right, you don't have to finish it ant further.

Can't help you with magnolia tho' I get my grey by adding a few drops of black polyurethane.