http://greenlightsurfsupply.com/pages/g ... -guide-a-z
read Swaylocks discussion forum. But highly focused on regular surfboards.
Basically-
If using more or less standard surfboard blank foam ( PU) then you should put 6+6+4 oz on the deck. One of the 6 oz layers can be deckpatch. Then 6+4 oz on bottom. This is pretty much minimum for board that will hold up to several years of use or more.
You can add 1 layer of 6 oz to tail in area of fin boxes to make fin boxes stronger- lots of forces on fins in kiteboards.
If you are using a lighter EPS foam- like a 1.5 to 2lb/ft3 ( difficult in thinner kiteboards= not recommended, but can b done) then you should add additional layer of 6oz all around- and should add some wood veneer or higher density foam ( 3mm thick Corecell or Divincell H80) to deck/foot area-
You also have to add high density foam around the fin boxes.
You have to seal the EPS with either light spackle or epoxy-glass balloon mix.
So if you can get a regular PU surfboard blank it is easier.
I´m building my boards so they will last a lifetime. Thats the best way to reduce waste and use resources most responsibly.
Using PU surfboard blank that is as thin as 10mm in spots.
Bottom is 7+7+4 oz- wrapped over rail to deck-( 7oz = 200g/m2)
Deckpatch is 6oz(165g/m2) under 1,5mm wood veneer, then 7+4oz wrapped over rail.
That us giving me 7+7+4+7+4 over rail. - keeps it tough in area where board gets a lot of bumps in transport.
Using Epoxy.
Board is 3200g including pad and fins.
I have also built EPS SUP boards- using builders EPS blocks - a 16ft 6" and a 10ft race board. Thats a different layup-
used 200g carbon twill then 7oz glass over- both sides
added HD 3mm foam on standing area with 7 oz under the HD foam.
HD foam inserts around fin boxes and leash plugs-