Gidday from downunder and a question if I may?

Rightio Im new so please go easy okay?!

Ive built two half models on the same backing board and am about to paint in the waterlines and then varnish them and build a nice Sheoak frame to finish them off... but prior to doing so am curious about the decks and hulls.

The designs are both by one BB Crowninsheild... the top one in the pic is his personal 40ft schooner "Fame" designed in 1910 and the bottom his Dark Harbor 12 1/2... now all those years ago they used to use canvas soaked in some sort of goop over the decking to seal it down... Im wondering what exactly would I use to replicate this on models such as these?



I am presently cutting out to 1/2in > 1ft scale a 56ft Broome Pearling Lugger and a 26ft re-design of that craft that I hope to eventually build full size... so I feel that I should at least try to get this first one right so Im ready to sail full and bye into the next

Any assistance would be brilliant thank you to any who respond
Take it easy
Shane