When using the provided San Juan decals on the Bachmann 2-8-0 modified by Soundtraxx with sound is a gloss coat required before applying the decals for best results or is the as received finish acceptable?
I lettered mine by cleaning the original painted surfaces with alcohol, then applying the decals using a thin wash of Champ's Decal Set. After it dries for about 24 hrs., I use more Decal Set full strength with a soft brush and let that dry. It results in no decal "blush" and I have been using that system for decades without problems. After I am satisfied that all is dry and ready, I spray it with Testor's Dullcote.
Oh, on freshly painted surfaces, let the paint dry until it has no odor before lettering.
That's my solution (no pun intended) and it may not work for everyone.
Ken