I haven't used lampblack, but I have used Linseed oil and turpentine on my bed wood. Linseed oil and turpentine is an very old wood preservative, it works well. It does need to be used every couple of years to remain effective. With that in mind I don't know that I would worry about proportions. I'd mix it till you think it is right. I use a mix of 50/50 linseed oil and turpentine. Another option is to heat up the linseed oil and add some Bees wax, also an old time wood preservative mix. You can very the thickness by adding more turpentine.

There was a study done here several years on bed coatings. I don't remember Linseed oil as being included, but it might add some options if your interested. I don't know that it made it to the techtips, but you should be able to find it in a search.

Larry


I don't own a vehicle that isn't old enough to drink.