I use 1/4" thick cork and TB3, don't be shy with the glue as the cork sucks it up fast. I wrap it with Saran wrap and then Ace bandage and let it sit as-is for 24 hrs. Then take the bandage off. It will take several more days to dry hard. I rough shape (gently) with a bastard file, then tune the shape up with a sanding block. Once I'm happy with the shape I slather it with more TB3 to strengthen it up and waterproof it. Then a few coats of poly over that.