PDA

View Full Version : Drying time


DanielO
02-01-2002, 02:33 AM
Just out of curiosity, I dampened a rag with mineral spirits and rubbed the corner of a painting I finished early last year. The color came off on the rag! This seems to indicate that the painting is not yet completely dry (it has long been dry to the touch). How long does it take these things to dry, anyway? I tested a painting I did ten years ago in the same way, and no color came off. A similar medium was used for both paintings (perhaps exactly the same medium, but my memory isn't good enough to guarantee that :-) -- the common stand oil/damar/turps medium.
Anyone?

paintfool
02-01-2002, 03:06 AM
Daniel, i'm pretty sure that the mineral spirits have broken down the damar. It is easly done. This is why i don't use damar except for varnishing. If the painting is a year old i'd say it's safe to go ahead and varnish it (if that's what you're wanting to do)
Cheryl

G.L. Hoff
02-01-2002, 01:47 PM
Originally posted by DanielO
Just out of curiosity, I dampened a rag with mineral spirits and rubbed the corner of a painting I finished early last year. The color came off on the rag!

A similar medium was used for both paintings (perhaps exactly the same medium, but my memory isn't good enough to guarantee that :-) -- the common stand oil/damar/turps medium.
Anyone?

Jeez....sounds to me as if the paint film wasn't very strong. By a year the film should be dry. Certainly possible that your medium was too thin, I suppose. And don't forget, turps is a stronger solvent than mineral spirits (unless they contain something else like xylol), suggesting that the actual paint film is flimsy. Was the painting varnished or not?

Einion
02-01-2002, 06:37 PM
After a year it is highly unlikely the paint film is still drying unless it is very thick; if you used a dammar/stand/turps medium in the top layers then it being under-bound is also unlikely. Sounds to me like, as Cheryl suggests, the white spirit is dissolving the dammar in the medium, a good illustration of why one should avoid resins in paint films.

Gary, mineral spirits are not all created equal, it is possible for them to have a higher proportion of aromatics than turpentine, making them stronger solvents.

Einion

G.L. Hoff
02-01-2002, 07:46 PM
Originally posted by Einion
Gary, mineral spirits are not all created equal, it is possible for them to have a higher proportion of aromatics than turpentine, making them stronger solvents.

Einion

Thanks but believe I mentioned that...xylol is quite a strong solvent...

colinbarclay
02-01-2002, 09:02 PM
Ok, this explains what i've seen guys doing at the art auction previews - surrepticously wiping away with solventy rags or qtips at the corners of "old" paintings !

I've had the same thing happen with stuff thats dry to the touch ( months old even ) but it was always such a slight amount of pigment that came off, that Ive never sweated it . I doubt its anything to do with damar, cause I never use the stuff .

I understand that a paint film doesn't really (I mean actually, chemically ) dry for years and years ... that its not so simple a thing as it FEELING dry.

As a kind of an aside question to whoever might know - why do the guys at the auctions carry those little UV lights ? Does a fresh inpainting flouresce or something under UV light ?

Colin