spraying clearcoat over bmf

Any clearcoat, gloss or flat, sprayed over a BMF will greatly reduce the realism of the metallic finish.

Rick

While that may be true, it is a good idea to do for 3 reasons.
1. protects the bmf from tarnishing
2. protects the bmf from ripping and tearing when using tape as a mask
3. protects decals from damage

Future worked good and I believe that laquers would work just as well.
Future initially frosted when I sprayed it on, but dried clear

I used Future over my BMF and it not only did NOT change the quality of the BMF, it enhanced the shine a little. Check out my P-47N in this month's reader's gallery.

Modelkid,
I use a lot of BMF on (gasp!!) civilian aircraft - mainly airliners - and I've found that there is absolutely no detrimental effects in spraying Future (as I do) over BMF. In fact, as John P states, it probably enhances the shine a little cuz the Future will fill the tiny scratches that happen when you burnish the foil down -
And as always, when in doubt - experiment on a little piece of the foil on a scrap model or a tim can or something. Tell us how you get on........
Cheers,
LeeTree