if its just for filling the weave then I would think just brushing it on with a large brush would work, or one of those little cheapy foam roller kits the little 4" kind with the tray,if your dead set on using the product.

your going to sand most of the material off anyway to get a smooth finish, for spraying it should flow like water through the gun when any material thats used for filling and is thinned out enough to flow through a gun,will take several coats to build up enough of the primer to fill the weave, call towerhobbies and ask there teck. to see what percentage of thinner they recomend,and what would be the best type for spraying that particular product, or for any application tips they may have and if the paint you have is recomended for the application your using it for.

alot people including me, use the auto primer in a spray can from De-rust-o its a high build primer that drys fast and sands smoothly and it comes in grey.
I also use the warbird colors primer I shoot through my airbrush which is fuel proof.

you might want to rethink using non fuel proof paint, it needs to have a clear coat to protect it from any fuel that gets on it and if fuel gets under it the paint will end up making a mess, if you bought it from tower they will take it back besides WBC paints there is also Nelsons paints as well.

another suggestion would be to search in the, kit building section, for painting planes, as well as the warbirds section there are a ton of ideas for paint and tecniques