Paul
I have a special mold that I replace the white gel coat with wood (Birch or Mahogany or any other type with no paper backing) in one piece and vacuum the the deck with my foam and the deck gains about 1 to 1.5 oz.
This process is only for a replacement or new build. The weight of the deck is about 16 oz with the hatch opening not cut out (owner cuts the hatch out), in other words you can deduct the weight of the hatch opening from the starting weight of the deck, also you have about 1.5-2.0 Oz's coming off when you trim the extra deck flange off after installing the deck.
The finished deck installed with the hatch cut out is about 12 to 13 Oz's ( my new birch deck came in at 11.8 oz installed and yes " The shoe makers kids are getting a new pair of shoes" and a new boat).The first hull out of the new mold is retiring and the new will be #140 out of the mold.
To save even more weight I am going to use Min Wax, like on a dinning room table, and wax the deck instead of putting a varnish or urethane finish on it, that is where the weight increases dramatically, using wax makes repairing a lot easier since you will not get a chemical ring or mismatch color or have to refinish the whole deck around the repair.
I did some decks for Dr.Greer and Ed Gelina and two others and they came out beautiful,these weights were before hatch cut out and installation, Ed's was 16oz and Doc's was 16.5 because it had a paper backing and absorbed some resin.
I have been getting my wood at
WWW.CONSTANTINES.COM, they kill me on freight since they package it in a SPECIAL HANDLING box, since the wood is fragile.
Only one thing I have not figured out yet is how to build a deck with a light or dark wood opposing center line strip, can not see the placement in the mold when vacuuming down the deck.
If anyone is interested in obtaining a wood deck contact me, you can supply the wood or I can, if you supply, I need to know what kind and thickness.
Bob Dudinsky
R.M.D.MARINE