Friday, March 16, 2012

Colbalt as a drying medium for oil painting

When I read Robert Glenns Twice Weekly Letter today this comment was at the bottom:

A drop or two of cobalt driers in the medium is the time-honoured method of speeding up drying in oils. Used sparingly, your paintings won't crack or crumble. Don't use Japan driers--they're too violent. While a lot of great artists don't agree with me, a good shine can be the final touch of quality. An uneven shine interferes with this illusion. Poor priming can be the culprit. Further, earth pigments (the siennas, ochres and umbers) tend to "sink in" more than other pigments and leave dull areas. This can often be corrected with a light spray of retouch varnish (comes in an aerosol can) right after painting. This helps in the drying too.

Now I have used Ihave used drying mediums like Liquin and Galkyd I have never used cobalt as a drying medium, so I thought I would learn more about it and share with you.
COBALT DRIERS:

Cobalt driers or as they are also known; Cobalt Siccatives are made from metal salts dissolved in either solvents or a combination of solvents, oils and resins.

The best Cobalt Siccatif available today is called "Cobalt Naphthenate" which replaced cobalt linoleate.

 Cobalt driers are VERY POWERFUL. If used in excess they can ruin a painting. Most experienced painters would agree that NO MORE than 5 drops of cobalt drier should be used per each 2 1/2 fluid Oz of any given medium.

 Basically Cobalt Driers are diluted in the oil painting medium if you are using one, or directly into the blobs of paint on the palette, but I do not recommend the later, because it is harder to control the amount of drier you are using. In short, Cobalt Driers are used to improve and speed the drying rate of oil colours.
Cobalt Drier is used with oil paints to reduce the time it takes for the surface of the paint film to dry.

Driers are best used with techniques that call for thin applications of paint, as in glazes. If your technique includes a thick impasto then cobalt driers are not for you. There are other driers that will work with thick bodied paint surfaces.

Pros:

  • Reduce the handling time.
  • Ease of use.

Cons:

  • Not to be used in water based paints or varnishes.
  • Can cause wrinkling and cracking when used in excess.

How does it work?

Using a paint drier with a drying oil, such as linseed, accelerates the absorption of oxygen. Drying oils dry through a process called oxidation. The oil molecule has one or two sites on it that bond with oxygen forming a new molecule. As this process occurs, these new molecules bond together in a process called polymerization. A solid film is left when the process is complete. This process will take place without the addition of a drier but will take significantly more time.

How much should you use?

The amount depends on the percentage of active ingredient in the Cobalt Drier solution you purchase. You will need to experiement with the painting medium and oils that you use. Begin by adding just a few drops to the oil and medium as you mix your paints on the pallette.

Warning:

Cobalt is a very toxix substance. In large concentrations it has been shown to be very harmful to one's health.

Keep this and all painting materials out of reach of children and use sparingly and with caution.

 For more information on art materials and safe studio practices check back. I will be reviewing different mediums for oil painting this month.


Cobalt Drier is used with oil paints to reduce the time it takes for the surface of the paint film to dry.

Driers are best used with techniques that call for thin applications of paint, as in glazes. If your technique includes a thick impasto then cobalt driers are not for you. There are other driers that will work with thick bodied paint surfaces.

Pros:

  • Reduce the handling time.
  • Ease of use.

Cons:

  • Not to be used in water based paints or varnishes.
  • Can cause wrinkling and cracking when used in excess.

How does it work?

Using a paint drier with a drying oil, such as linseed, accelerates the absorption of oxygen. Drying oils dry through a process called oxidation. The oil molecule has one or two sites on it that bond with oxygen forming a new molecule. As this process occurs, these new molecules bond together in a process called polymerization. A solid film is left when the process is complete. This process will take place without the addition of a drier but will take significantly more time.

How much should you use?

The amount depends on the percentage of active ingredient in the Cobalt Drier solution you purchase. You will need to experiement with the painting medium and oils that you use. Begin by adding just a few drops to the oil and medium as you mix your paints on the pallette.

Warning:

Cobalt is a very toxix substance. In large concentrations it has been shown to be very harmful to one's health. Keep this and all painting materials out of reach of children and use sparingly and with caution


" POST YOUR OPINIONS IN THE COMMENTS" or email me at delilah@artbydelilah.com
Join Our Email List
Email:  
For Email Marketing you can trust
Pin It
Home Page Art by Delilah = http://www.delilah-smith.com

1 comment:

David Larson Evans said...

I'm a Liquen man myself but I found but I found your post very informative... thanks