A shipwright friend is putting together a house frame, sills and floor all very green alaska yellow cedar. He's putting his traditional boat application on all endgrain and worked edges to keep the checking down. His recipe:

Boat Sauce:
Old varnish, the older and thicker, the better
turps
linseed oil
pine tar
driers optional

The aim is to get as much pinetar in the mix as will paint on easily. Easy on the linseed. It's a feel thing, but one I'd guess anyone could figure out fairly quick.

And it smells good!

Zach