Progress of Sun-thickened Raw Linseed Oil
I started this small batch of raw linseed oil in April and it has been exposed to sunlight every day since then. I have done several experiments with raw linseed oil all of which are covered in Shellac, Linseed Oil, & Paint – Traditional 19th Century Woodwork Finishes.
The oil started out much darker and less viscous and with the action of the sun it has lightened in color [with the chlorophyll being bleached out] and it has thickened up. Because it is oil I let it stay outside even in the freezing weather.
The other morning [it was 17 degrees F] I noticed that the oil had clouded up, so I took a photograph of the cloudy oil.
I took the oil inside and allowed it to warm up overnight and it clarified. Could be residual moisture in the oil that cause the turbid appearance.
I will keep it in the house in a sunny window and let it continue to thicken up. I do open the bottle occasionally and have noticed that the odor is much milder than fresh raw linseed oil.