Thursday, November 5, 2009

Drying times

Oil paints dry by oxidization. That is, the paint adsorbs oxygen and polymerizes, forming long chains of molecules that are leathery and strong. They are real tough, you can find 19th century paintings in many antique shops and they aren't particularly valuable or scarce. Until modern times oil paintings were one of the toughest things man made. Linoleum is the name that was given to a floor covering product that was made by soaking sheets of cardboard in linseed oil. Today what we call linoleum is no longer made this way, but you will still occasionally happen onto a piece in old farmhouses in New England.

How fast your paintings dry is controllable to some extent. Here are a few of the things which influence that. The first would be your medium, if you use no solvent and lots of linseed oil your paintings will dry very slowly. If you use turpentine your paintings will dry more quickly. Many painters today, myself included, use alkyd mediums. The two best known are Liquin and Galkyd. Both of these products give a faster drying time. I wrote more about these here. Alkyd mediums speed drying a lot.

Another way of getting alkyd into your paintings but continuing to use the medium that you are using now, is to switch an alkyd white. Winsor Newtons Griffin line is a good one to try, you can use it mixed 50/50 with a regular titanium white if you prefer. This is a sort of set and forget solution, that is all you have to do is use that white and the painting will dry quickly, as white is in most of your mixtures, particularly those which are thick and would dry slowly.

There are dryers that are made to be added to paint. The two most common ones are Japan dryer and cobalt dryer. Japan dryer is a catchall name for a number of different concoctions the most common of which contains napthenic acid. These days with the prevalence of alkyds painters don't seem to use dryers as much as they did years ago. Nowadays Japan dryer seems to be more of a craft supply or used in the building trades rather than over here on the fine art side of the wall. I think that is a good thing.

I remember R.H. Ives Gammell holding up a little bottle of cobalt dryer at us and warning "gentlemen there is enough dryer in this little bottle to crack every painting you will make in your lifetime" His advice was not to use the stuff and with a couple of exceptions I have followed that advice. Cobalt litholeate dryer is poisonous and is commonly added in small amounts to mediums or into the white on the palette. I do recommend against its use. The problem with dryers is this........

They may continue to dry the paint film more than is desirable until it is dessicated, shrunken or embrittled. Oil paint is so tough because it remains gummy rather than drying out completely. I was taught long ago to say when asked how long it would take for a painting to dry the answer was "dry to the touch in three days, dry all the way through in four hundred years. I tell clients this and the other things on this page, because it is important for them to be reassured that their expensive painting is going to last a long time. I have asked people what the picture on their new flat screen television is going to look like in three hundred years.

Different pigments have different drying times and that will effect how rapidly your paintings dry tomorrow I will discuss that.

19 comments:

willek said...

Very informative post, Stape. I used to use cobalt drier years ago and I still have some from that time when I did a lot of glazing. Paintings I still have from those days are still good. I was taught to make up a medium of equal parts of turpentine, Damar Varnish and Stand Oil. To this was added six drops of cobalt dryer to a 3 ounce bottle. I still use the medium once in a while. I think that if it is used throughout the painting, from the beginning to the end then the bottom layers will dry before the top ones, thus avoiding cracking. Because of the continual drying you mention, I wonder if it would be safest to only use it on a stable panel rather than canvas. I don't like using commercial mediums. We don't really know what is in them and they can change them without telling us. They are also more costly. I also suspect that the purple tinge in some of the proprietary mediums is cobalt.

Ben Bauer said...

I do agree with Liquin and Galkyd but tend to sway more on the side of the M. Graham Alkyd/Walnut medium. I am not very fond of how both the Liquin and Glakyd are the most consistently inconsistent mediums I have purchase, foggy at times, too runny at times, and so on. I do like the S Christensen - oiling out technique with Liquin the most though, I used galkyd alot in college 7 years ago and thought the product was much better then, than now - Have you experienced this as well? Have you ever used the calcite mediums from Natural Pigments? That is one I have had my eyes on..... I have become a nitro materials junkie for many years now and always game to find the one that suits me best, linens, primers, paint, substrates,brushes,knives, and especially mediums and the effects that they can have.....

By the way you speak of many types of pigment, paints, and materials, and such.... Have you tried Kama Pigments before?
I learned of RGH through your site and have found a new home for ordering paints in quantity and tubing. Except white - since you have spoke of it in the past would adding stand oil it self make it alittle stiffer to work with, too buttery for my likings.

Oh by the way i am totally looking for the MN winter as well, I am a lover of winter greys!!!!!!

Thanks and take care......

Tim said...

Ill chime in with Ben on this, I do love me my Graham Walnut alkyd, I got some on the recommendation of William Whitaker, and I
haven't looked back.

When I first started a few years ago, I wanted to try out a bunch of different dryers, so I got myself a liter bottle of galkyd, used that to the end, then a liter bottle of liquin, and used that. I dont like painting with something that smells like a tire cleaner, and the walnut alkyd is awesome. I just have it in a dropper bottle, and every time i pleine air, i drop one or two drops in to the paint daubs and mix em up. (Maybe three drops in the alizarine and cads)

Gregory Becker said...

Some people suggest to leave the painting out in the sun just not to leave it out over night, but doesnt that make the pigments lose lightfastness?

Deb said...

I'll second what Ben said about Liquin, which is what I usually use. It is convenient and I'm always able to get it locally. Living in a small town in a rural area, I order most supplies online -so being able to get this easily and quickly is a real plus. But, it does seem to vary greatly from bottle to bottle. Sometimes very gelled and thick, sometimes oily and runny.
Stape, judging from the early nature of these comments, I'd say many of us tune in with our morning coffee.. Start the day with Stape. Is that a good thing or a bad thing?

mariandioguardi.com said...

Wow, this is such a timely post. I painted a large piece, finishing two weeks before a show. I left gallery sides on the painting substrate for last. I painted the sides using the Old Holland "Quick Drying Medium". It never dried (we are talking three weeks before I scraped it off). I wasn't able to show the painting.

I re-painted using Liquin. the painting is drying alright. I then did a test strip with the same pigment(Williamsburg cad yd mix) and the two different mediums (Old Holland and Liquin). The Liquin has dried, the Old Holland medium is still very wet. Wetter than I think just the paint would be.It was an old bottle think the volatile dryer from Old Holland evaporated from the bottle and left the medium useless or worse.

I don't like Liquin much, though it does work. I am getting me some of that M.Grahm Alkyd/Walnut medium today to try.Typically I do not use medium at all im my pallet knife paintings but on occasion I need it and I will use it. And I recommend dating all your mediums when you get them or mix them.

Richard J. Luschek II said...

I have always fallen on the side of using little to nothing as a medium. Maybe I should experiment more.
Am I the only one that seems to suffer a horrible headache after using Liquin? I sort of stopped using it due to its deadliness. Maybe it's just me.

I am also wondering about drying paintings in the sun. In the summer I have been known to put paintings on the dash of the car to dry fast. I know Maxfield Parrish would cook his many layers of glazes in the sun. Oil paint wants natural light. Right? I know oil paint will darken if stored in dark places, and sun will bleach them out, but is there an issue of exposing the painting to high heat or heavy sunlight?

One final question. This is about the techniques of Walter. What would be the archival qualities of clay over dead cat?
(sorry folks- inside joke)

Jeremy Elder said...

I just came across the term "painting jelly" the other day. I believe Meglip is a brand of that. Is this similar to an alkyd or something completely different?

Stapleton Kearns said...

Wllek:
Thats a pretty standard historic medium called VTO as I am sure you know..............Stape

Stapleton Kearns said...

Ben:
I haven't noticed a change in the Liquin. I like the walnut oil alkyd medium too, however it has a warning on it that it may spontaneously cumbust and that makes me nervous. We are so over lawyered these days that it is hard to know what to diseregard and what to fear.
I don't dislike the RGH white so much as I LOVE the Lefranc white.
I don't know about adding stand oil to it, that might br an interesting experiment. Have you tried the Lefranc?
............Stape

Stapleton Kearns said...

Tim: That is a good way to do that. I "beat" my whites and whatever needs it in the winter to make them more moveable in the cold.
...........Stape

Stapleton Kearns said...

Gregory:
I have done that on painting trips many times and never had a problem.
...........Stape

Stapleton Kearns said...

Deb:
Alkyd mediums are made so they sit right on the edge of gelled and runny. I think they change states easily according to temperature and who knows what. It doesn't seem to effect the way they work much.
...................Stape

Stapleton Kearns said...

Marian:
As I have noted, the best medium is probably no medium. The Walnut oil alkyd medium is REAL shiny.
.......Stape

Stapleton Kearns said...

Richard.
I don't think drying a painting in the sun is a big deal. As I said above I do it on painting trips. I don't think I would leave a painting out in the sun for too long. When I had my gallery paintings would sit in then front window in sunlight for weeks at a time and it didn't seem to hurt them. I would not do that to a historic painting. My own if I screw it up I can fix it.

I think that cat will be archival after the biological components have atrophied.
................Stape

Stapleton Kearns said...

Jeremy: I believe I will answer that in the blog tonight.
.........Stape

Ben Bauer said...

I have tried LeFranc and love it as well, Schmid recommends it as well. I most prefer Rembrandt white a little stiffer but great to handle. I am a fan of these types of blogs, materials and idea trades!

B

jeff f said...

I use stand oil, Canada Balsam and turps or Spike oil.

It dries very quickly and can be used as a retouch varnish by thinning it down with a little turpentine.

I also like some of James Groves mediums such as the Cobalt gelling medium

abuelitoluis said...

1/13/2010: Hello Mr. Kearns and readers. My name is Louis Velasquez and my website is www.calcitesunoil.com

I read with interest the issue of 'drying' of the oil paint. As the artists wrote, there are many ways = use of solvents, use of synthetic resins like Liquins, etc. The dangers of adding metallic 'dryers' was also pointed out.
My website has much information that addresses this issue. Meanwhile, here are things one can do= Use a fast drying linseed/flax oil instead of the industrial art store Linseed, or Linseed Stand oil. This Superior oil my site describes is easy to process. Instructions are on my site. The next thing is to create a ' half-white' for the initial underpainting stage. This is a simple mixture of a small amount of 'fast drying' umber to the 'slow drying' white oil paint. tho its called 'half-white' it is not a 50/50 mix. just a small amount will help drying. The underpainting srtage needs to dry fast. When doing the over paint stage, dont use the 'half-white', since slower drying is ok. Also, this use of a muted white in the underpainting stage adds to value and chromatic and hue beauty as you over paint in brighter clearer colors and pure white. My site also has a NEW PAGe titled 'CSO-EGG' which is a new egg tempera medium. I recently developed this new medium and it greatly accelerates the underpainting stage. My development is a variation of the ancient method of underpainting in egg tempera and over painting with oils. But, it is a new medium. If you have questions, I will respond. Thank you. Louis Velasquez