Add absorbent materials such as sawdust or cat litter to the paint if there is more than just a little left.
Drying oil painting in the sun.
How to make your oil paintings dry quickly.
After that i embrace the slow drying time of oil paint rather than try to avoid it.
Avoid extreme heat like hairdryers as this will only make the process worse.
The sun will take away the color.
Pour some oil about an inch into a wide dish cover it with a propped up lid i e.
Two paint using thin layers and washes which will dry reasonably quickly.
In general i agree with what has been said so far its not a good idea to leave an oil painting in full sunlight for an extended period of time this will affect certain pigments.
One leave the painting to dry in a well ventilated open area where air circulates a fan helps.
Use an alkyd medium with your colors.
Also paint is slow to dry in a cold environment so a warm room is preferable.
To minimize debris getting in but so that the air can flow through.
Oil paintings need daylight.
Not direct sunlight due to fading and too much darkness will cause it to yellow.
This process is demonstrated in the painting below.
Bugs will get stuck to it.
Stir it periodically to hasten drying.
I typically find this is not such a good method as the paint dries too.
6 mix your paint with a solvent like turpentine or liquin.
As you may have guessed from the prior answers drying an oil painting in the sun is the wrong thing to do.
Use alkyd white instead of normal white to mix with your oil paints.
Since linseed oil dries faster than other kinds of oil mixing a little extra linseed oil with the paint on your palette can help speed the drying time of your painting.
A couple of other things to think about that.
Sun thickened linseed oil is a created by exposing the oil to the sun to create a thick syrupy somewhat bleached oil with similar brushing qualities to stand oil.
Buy some commercial paint hardener or dryer to dry paint in a hurry.
When i start an oil painting i will usually thin the paint using odorless solvent so that it becomes a thin wash with a watercolor like consistency.
Combine linseed oil with the paint on your palette.
Pour paint from a full can into other cans or containers a little in each so it dries quickly.
However there is an important exception and that is when an old painting is suffering from discoloured or yellowing of the varnish layer.