Filler for canvas

I have read Stelmok&Thurlow and it makes some reference to a filler with linseed oil, japan dryer,etc. Is there anywhere I can get some pre-mixed filler? I also need to know how to apply it and how long I have before it dries.

 

You can check out the online builder catalogs at:
http://www.wcha.org/builders/index.cgi

I know Northwoods Canoe Company sells filler, some others may as well.

 

Thanks. It eases the mind to know that I am using filler from the experts.