Weight Watchers

How much weight does painting an IOM really add?  In the past this question has never bothered me that much.  Lets be fair I'm building a balsa hull shell and covering it in fibre glass.  If I ever struggled to build an IOM below minimum weight (which I haven't to date) I would omit keeping the balsa as an integral part of the hull and use the planked hull on it's shadows as a plug for a complete 100% FG hull.  Now that would be interesting to do just to see the weight and stiffness differences.  Although in both instances a paint finish is usually required.
I'm using Epiflanes 2K paint as it was first highly recommended to me by the builder of the UK Britpop.  I painted my last IOM with it and it is indeed very very good paint.  I'm expecting (hoping) to apply three coats in a time scale which doesn't require sanding between coats.  Then, when I think the paint has had adequate time to harden = 4-5-6... days I'll fair it off with 800-1200 wet or dry and buff it back to a high gloss finish with rubbing compound.
So before all this starts here's the near bare hull on the scales; 663g or 23.4 oz

Edge in the raw

After applying 3 coats of 2k paint to the hull and 2 coats of Satin Cote to the decks the hull turned out 18 grams heavier.  If I had chosen a dark hull colour then the paint would probably have covered in 2 coats saving approx 5 grams or put another way the weight of the small M4 bolt which secures the fin and ballast