The Oil has some characteristics of Stand Oil but dries significantly faster. I also noticed the initial adhesion is much greater than stand oil. I just love the all around variety one can produce by using Sun Thickened Linseed Oil.
Before I got started I read a few books that I thought could point me in the right direction. The Artist's Handbook by Ralph Mayer, Max Doerner's The Materials of the Artist, Parkhurst's The Painter in Oil and Oil Painting Techniques and Materials by Harold Speed all came in handy. Along with the books I found a couple of great artist blogs online that helped answer any other questions I had.
The first thing I did was buy a cheap cooking sheet and found an old piece of glass. To allow the oil to breath during the thickening I tied twine around the cooking sheet. This twine kept the glass from touching the cooking sheet at the same time protecting the oil from dew, rain water and insects.
|Linseed Oil Under Glass|
I merely placed the flat sheet filled with High Quality Cold-Pressed Linseed Oil out in the yard where it would receive direct sunlight most of the day. So now I play the waiting game, every couple of days I will check on it and stir the oil. I what to make sure that the oil does not skin or become thicker then what I prefer.
|Sun Thickening Setup|
I had read that the oil should thicken within a week or two depending on the weather. So I was a little confused that for me after three weeks not much had changed. Then I realized that I put too much oil in the sheet pan. So to remedy this I separated the oil into two sheet trays and within three days the oil rapidly thickened. I found that about 1/4inch of oil was just right. Even though it took longer I don't believe it was wasted time. All the time the oil was sitting there it was collecting air assisting to its oxidization.
Despite taking precautions to protect the oil the insects and water was almost unavoidable. One of the batches got soaked during Hurricane Irene. Nonetheless there was ways to fix that too. Before bottling them up I filtered the oil in cheese cloth to get rid of the bugs and shrapnel. The batch with water I just left bottled in the sun until the water and oil eventually separated.
All and all it was a great learning experience and I wound up with about three years supply of Sun-Thickened Linseed Oil.