My friend suggested B 67 might work as a grain filler.... I'm not a scientific person so the data sheets mean nothing to me. What I can understand is that the solvent for 67 is cellulose thinners or naptha. However the data regarding durability doesn't make any sense to me. There is also no published data on elasticty - somthing fillers must have if they are to work with wood. I guess i'll have to do some testing.