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Effect of cold on drying times?

Hi all,

I was wondering if anyone had tested the difference temperature makes to keeping paint open on a palette (either normal tubed paint or Geneva)? More specifically storing in a fridge compared to storing at a normal room temperature..

Thanks,
Richard

Comments

  • Since I have started placing my pallet inside of a plastic box with a closed / sealed lid and a few drops of brush dip - they stay open longer and this is in the clime here in Hawaii.
  • Wow. A paint box unaffected by lava? Extraordinary. 
    alsartSummer
  • edited July 20
    I store my mixed W&N paints stored in plastic film containers and snap caps in the refrigerator, keeps for a very, very long time. I don't have enough space in a free refrigerator to store my wet pallette in. Air conditioning does indeed help extend the life of my paint, absolutely yes, by as much as 5 days. I have extended a wet pallette for 6/7 weeks no worries. In fall & winter months my pallette will stay wet longer than in summer months. I keep my wet pallette near a window in fall and winter to keep it cold and extend the life of paint. Sometimes I may need to add a drop or two of SDM to the paint on the pallette along the way. I firmly believe that a refrigerator for storing your pallette in order to extend life of paint is a good choice. But I also add that air tightness, the least amount of air the better, helps a lot too. If condensation occurs, it dries/evaporates naturally in a very short time.
    Summer
  • @Forgiveness ; Did you ever find a resource for obtaining those 35mm containers you use to store paints?  I have a few left over from the old days of film cameras but not enough to use them for paint storage.  I'd love to order a few dozen to start with.  Summer
  • edited July 20
    @Summer, Not yet found a new source, but possibility on the horizon where I live, as old film cameras seem to be making a come back! I'll be sure to let you know when I find one. The ones I already have I received from a friend who just had too many from his own camera, in mid 1990's. I started with a few dozen, now I am down to only a few left and need to replace them as well. Fantastic containers for storing mixed oil paint. I am also considering purchasing blank paint tubes online, as a possibility.
  • Thanks all. The sustained hot weather here has caused a lot of paint to dry a lot quicker which is frustrating when I can't paint every day.
  • Richard_P

    A trawl through the WC forum produced this helpful post answering the question about how to speed up drying time. See point 4.


    http://www.wetcanvas.com/forums/showthread.php?t=600977&page=2

    1. Oil-paint dries by oxidative polymerisation
    Carbon=carbon double bonds between unsaturated fatty acid components of the triglycerides in the oils are cross-linked into a high-molecular-weight polymeric network, by interaction with oxygen molecules. This causes a change from liquid to solid.

    2. Evaporation is not a significant contributor to the drying process
    Solvent used in paint-mediums will evaporate, and there may be some minor degree of evaporation of volatile components within the oil, such as free fatty acids. But the main drying process is oxidative, as described in point 1.

    3. Oxidative polymerisation requires Oxygen
    And the principle source of this is diffusion through the paint-film from the atmosphere. If you paint thickly, there will be a distinct concentration-gradient of oxygen-concentration between the paint surface and the interior. This is why paint skins over. If you allow free-air-flow around the painting, you cannot improve its oxygenation without increasing the actual % or pressure of oxygen in the air (This would still not be a good way of speeding the drying of thickly-painted works.)

    4. Oxidative polymerisation is temperature-dependent.
    An increase of 10ºC will approximately double the rate at which paint dries. This is the main reason why paintings dry faster in the warm summer than in the cold winter. In cold conditions, gentle warming of the painting by 10 to 20 ºC willincrease the drying-rate very significantly - within the range of drying rates seen naturally in different climates. This degree of warming will not harm the painting.

    Over-heating the painting, on the other hand, is not a good idea (I'd avoid taking the temperature of the painting above 45ºC), as this is likely to lead to skinning, to cracking, and to discolouration.

    5. Oxidative polymerisation is aided by light
    Some of the reactions in the drying process are free-radical mediated, and are helped by exposure of the painting to reasonable levels of daylight. Light exposure also helps prevent primary (reversible) yellowing.

    So, to directly answer the original poster's question
    Put your painting in some gently warm place (such as hung on a wall above a radiator), and exposed to reasonable levels of daylight. This will increase the drying rate by a factor of 2 or so (up to a maximum of perhaps 4, if you are somewhere particularly cold). Do not expose the painting to environmental conditions more excessive than you would find in a warm, well-lit room, in summer.
    So with my drying times using wm oils with SDM at ten to twelve days for the slowest color in summer, I can expect about three weeks to a month in winter. My drying area varies in a diurnal range 14 to 20 centigrade in winter and from about 20 to 33 centigrade in summer. Modified by heating and cooling for part of the day to the mid range. Humidity is another cyclical influencing factor.

    Denis



    PaulBalsartSummer
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