How do you make linseed oil dry?

Answer 1

It all depends, I suppose, on your usage. The 100% safest way is just to buy it at the store... never try to make it yourself by boiling raw linseed oil as you'll no doubt wind up with a pretty good fire on your hands.

Today's "Boiled Linseed oil" is mixed with chemical agenyts that cause it to dry more quickly than raw linseed oil. Heating raw linseed oil (under laboratory conditions!) causes it to polymerize and oxidize, making it thicker and shortening its drying time. Again, kids, don't try this at home!

Answer 2

Linseed oil doesn't actually "dry" in the usual sense - it oxidises, reacting with air to form a dry film. This can take several days to be touch-dry, and the reaction continues for a long time, making the film gradually stronger. The drying time depends on many factors, including the "purity" of the oil, whether it is "polymerised" or "heat-bodied", and so on. If used on furniture, wipe it off and buff it with a clean cloth. The wood will tend to absorb the oil, so you may wish to repeat this several times, waiting a few days between coats. A greater number of coats will tend to produce a glossier surface. For more information, try http://en.wikipedia.org/wiki/Linseed_oil