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campsart
07-03-2001, 05:42 AM
I watched a movie recently that was titled "Incognito". This film was about a very talented artist who forged masterpieces. He was propositioned by some shady characters to create something unique. After much research, he decided to create a lost painting by Rembrandt. It was a portrait of his father. Not only was his technique and knowledge very impressive but how he dried the painting is what caught my attention the most. I noticed how, at various times, throughout the process he used a hot air gun on the canvas as well as heating it in an oven! Am I trying to justify my use of the Genesis heat-set paints? I don't know. What I would like to know is...can traditional oils be heat-set in anyway or will it screw up the chemical makeup? Maybe it was typical hollywood license but I was excited to think that if it is possible to dry traditional oils, maybe I'm not too far off using the newer type. I realize Rembrandt didn't have a hot air gun but would he or anyone else have tried to heat their works in an oven of some type?

Your help please...

David

Mario
07-03-2001, 06:11 AM
Hi, the answer is a resounding NO...Oils are NOT affected by heat, what dries them is good ventilation so maybe a fan or other air circulation would help. It sounds like the movie had some imaginative writing without much research, also I've heard that the Genesis Oils are not really Oils but rather plastics...don't know , could you inform me on that one? thanks

Verdaccio
07-03-2001, 09:27 AM
While Mario is essentially correct - oils dry via exposure to oxygen, putting a painting in an oven will speed the drying process because it dries the air around the painting, heats the support and the paint, and promotes faster venting of any solvents out of the paint. This is essentially why a painting in Arizona dries much faster than a painting in Florida. I have illustrator friends that do this when they are on a tight deadline.

HOWEVER...I would NOT recommend doing this as I suspect that it may weaken the structure of the paint and possibly effect it's longevity.

I suspect that the movie was using this trick not to dry the paint, but to imply that it artificially ages the paint in some way.

IRDOC
07-03-2001, 02:37 PM
I must also stress no no no oil must dry from the inside out.

campsart
07-03-2001, 11:14 PM
Thanks all...

David

Patrick1
07-04-2001, 06:24 AM
I did a 12x16 oil painting and I left it to dry under a 20W compact fluorescent light bulb in a desk light pointing right at the painting, and about 5" away. Depite using a lot of linseed oil, the painting the next day was dry to the touch. I couldn't believe it. It seemed like it dried the way it would normally dry after about 3 days. I read that light speeds up drying. campsart, you might want to try this. It seems to work. A 24" fluorescent shop light hanging from the ceiling would be even better than a compact fluorescent.

Patrick.

Patrick1
07-04-2001, 07:27 PM
Also, if oils dry by oxidation (which I'm 90% sure they do), then heat will speed up the chemical reaction, as it does with other chemical reactions. My grade 13 chemistry teacher said that
for every 10 degrees celsius warmer, a chemical reaction occurs twice as fast. I don't know if this is exact or an approximation.

I would still definitely not recommend putting a painting that you worked hard on in hte oven. You know, about 10 years ago I spray-painted the handlebars of my bike a red color (alkyd paints), and I wanted to speed up the drying. Baked them inthe oven. It sped up the drying all right, but the red color became a duller, darker, slightly brownish, brick-red color. I wouldn't want to risk this happening to a painting I did. But I'm sure that under a fluorescnt light is completely safe.

Patrick.

Mario
07-05-2001, 08:22 AM
Flosrescent bulbs do not throw heat anyway so I can't understand what this light would have to do with drying...I wish it did though, anyone know??

Patrick1
07-05-2001, 10:51 AM
Well, they don't put out heat like incandescents (regular light bulbs are better heaters than they are light sources), but fluorescents do still gererate considerable warmth at several inches away...enough to definitely speed drying. And fluorescent tubes emit light and heat more evenly than a bulb.
I'm pretty sure Grumbacher said, on their message board, that light speeds up oil drying. Since it's a form of energy, I wouldn't be surprised. Just as important, light is needed to prevent/minimize the yellowing of linseed oil as it dries. I just finished an oil painting and am leaving it out in full sun today. I'll see how fast it's dry to the touch.

Patrick.

allen
07-05-2001, 11:22 AM
Originally posted by campsart
I watched a movie recently that was titled "Incognito". This film was about a very talented artist who forged masterpieces. He was propositioned by some shady characters to create something unique. After much research, he decided to create a lost painting by Rembrandt. It was a portrait of his father. Not only was his technique and knowledge very impressive but how he dried the painting is what caught my attention the most. I noticed how, at various times, throughout the process he used a hot air gun on the canvas as well as heating it in an oven! Am I trying to justify my use of the Genesis heat-set paints? I don't know. What I would like to know is...can traditional oils be heat-set in anyway or will it screw up the chemical makeup? Maybe it was typical hollywood license but I was excited to think that if it is possible to dry traditional oils, maybe I'm not too far off using the newer type. I realize Rembrandt didn't have a hot air gun but would he or anyone else have tried to heat their works in an oven of some type?

Your help please...

David
Hi David, that movie was pretty cool, I enjoyed it too. As far as paints (though not 'traditional' oil paints) being heated, forgers have done it in the past. John Godley's book 'Master Art Forger' (the story of Van Meegeren), recounts the painter's methods of using lilac oil, phenol, and formaldehyde. An interesting read.

Mario
07-05-2001, 12:45 PM
Hi Domer, leaving a wet canvas out doors is asking for trouble. Try picking off all of the dirt and leaf particles etc. that get stuck on it. The thing about light being energy is far out...too far, I'd be very interested if you could find that exact source of info.

sgtaylor
07-05-2001, 03:11 PM
Originally posted by Domer
I just finished an oil painting and am leaving it out in full sun today. I'll see how fast it's dry to the touch.

Very bad plan. Direct sunlight is very injurious to oil paint films during drying. This has been documented all the way back to Van Eyck.

Raising the temperature of your studio a bit probably couldn't hurt anything, but I would not expose the painting to elevated levels of light.

There was a thread on here a while back about putting lead shot into your medium to improve drying times. This is about the only thing I would consider doing.

Whatever you do, don't dry paintings in direct sunlight. You might not see any problems right away, but problems will eventually show up. I don't have any sources directly at hand, but I know that A.P. Laurie talks about this, and I think there is something about it in Eastlake.

wnabors
07-07-2001, 12:54 AM
paint DOES have to dry from the inside out...overnight it is usually dry enough to work without smearing previous work. But it usually
depends on how thick the work you have done is. Remember with oils and even some acrylics only the skin on the outside has dried. Scratch a particularly thick area-break that skin and presto..you find wet paint this can be true weeks after you think it's dry!! I have tended to work in layered glazes and because they are thinner (for transparency) they dry a little faster. Some of the things I have tried to speed up drying have yellowed with age and I'm heartsick about them. (I HATE the learning process).
Some of the things I hope to pick up here at wetcanvas are tips on various thinning mediums, drying mediums, finish glazes ect..and tips on how to use them.