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canvasishome
04-11-2002, 10:52 AM
Hi Folks,

Looking for a few comments about the differences between Cobalt Drier versus Japan Drier.

Other than the chemical makeup, what can I expect from each? I noticed the cobalt drier was very thin and watery, had a purple tone, and came with a BIG health warning. The Japan Drier was almost clear, a bit thicker, and didn't contain the health warning.

Do they both perform the same basis function (drying oils quicker)? How quick is quick? Do they leave a glossy or matte finish?

Whew! Thanks for your help, gang.

-dk-

Luis Guerreiro
04-11-2002, 02:51 PM
Originally posted by canvasishome
Hi Folks,

Looking for a few comments about the differences between Cobalt Drier versus Japan Drier.

Other than the chemical makeup, what can I expect from each? I noticed the cobalt drier was very thin and watery, had a purple tone, and came with a BIG health warning. The Japan Drier was almost clear, a bit thicker, and didn't contain the health warning.

Do they both perform the same basis function (drying oils quicker)? How quick is quick? Do they leave a glossy or matte finish?

Whew! Thanks for your help, gang.

-dk-

Hi,

There is no similarity between Cobalt driers and Japan Driers.
Let us have a look at them:

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.

JAPAN DRIERS

Formerly, I think they were oil varnishes. Today they are best known as JAPAN SIZES or indeed JAPAN DRIERS. They are used, among other applications, to work as a size in GILDING, when such size is required in oil painting. The only JAPAN GOLD SIZE I ever worked with is the W&N one which can be used on top of a completely dry oil painting layer where gold leaf is to be applied. The Japan size acts as a "mordent" and grabs the gold leaf keeping it in place. When dry, the gold leaf can be further glazed with oil colours, etc...
I know Japan Driers were used for other purposes in the past, but I am not familiar with those. Japan Drier is brushed on and soon it become tacky. It is traditional to check this by touching it with the finger nuckles. If it "pulls" your skin enough, it is ready to receive gold leaf. Japan Drier is also used in artistic book-binding for gold leaf artwork over polished leather.

CONCLUSION:
Cobalt driers are used to dilute sparingly in oil painting mediums.
Japan driers are used for gilding, either direct over bole or over oil painting dry coats.

Best regards

Luis:)

canvasishome
04-11-2002, 03:57 PM
Thank you, Luis. Your information was very helpful. I also found a bit of info. on the Grumbacher site.

Seems like both must be used very sparingly, as too much can cause adverse effects to the paint.

-dk-

paintfool
04-11-2002, 09:49 PM
Originally posted by canvasishome
Seems like both must be used very sparingly, as too much can cause adverse effects to the paint. This is also my understanding. This is especially true of paintings done with thick applications of paint. The driers speed up the drying time of the outer layer of paint before the inner, and leaves a fragile skin on the top. This can eventually lead to cracking. I would personally stay away from them. I do have a bottle of Cobalt drier but i've yet to use it. I think i had planned on experimenting with it and changed my mind after some reading and thought. One of these days i will open that bottle but the reality of oil paints are that they are slow drying. It's just the nature of the beast and has it's advantages. If i really want a fast drying paint for an underpainting i use Alkyds.
Cheryl

canvasishome
04-12-2002, 09:50 AM
Hello all,

Just another word on this:

I now understand more on these driers (it helps when you read the labels a bit better) ;)

Japan Drier is composed of the Cobalt Drier, plus terps, alkyd resin. So, it is a type of medium which comprises the Cobalt.

All that being said, I think I'll stick with my Stand oil + terp medium and occassionally throw in a bit of Liquin if quicker drying is needed.

Again, thanks for the help with this.

-dk-

Luis Guerreiro
04-13-2002, 04:03 AM
Originally posted by paintfool
This is also my understanding. This is especially true of paintings done with thick applications of paint. The driers speed up the drying time of the outer layer of paint before the inner, and leaves a fragile skin on the top. This can eventually lead to cracking. I would personally stay away from them. I do have a bottle of Cobalt drier but i've yet to use it. I think i had planned on experimenting with it and changed my mind after some reading and thought. One of these days i will open that bottle but the reality of oil paints are that they are slow drying. It's just the nature of the beast and has it's advantages. If i really want a fast drying paint for an underpainting i use Alkyds.
Cheryl

Hi Cheryl,

Cobalt Driers (of which cobalt naphthenate is the best grade) are safe enough if used with care. The general rule is to use as maximum, 50 drops of it per each pint of medium.
The best siccative agents still are lead and manganese salts because these dry the paint layers from the inside out.
Please have a look at a post later here about manganese and lead concentrate driers.
PS: You look lovely in yout flashing tinyhead.:p

Luis :D

Luis Guerreiro
04-13-2002, 04:29 AM
Originally posted by canvasishome
Hello all,
Just another word on this:
I now understand more on these driers (it helps when you read the labels a bit better) ;)
Japan Drier is composed of the Cobalt Drier, plus terps, alkyd resin. So, it is a type of medium which comprises the Cobalt.
All that being said, I think I'll stick with my Stand oil + terp medium and occassionally throw in a bit of Liquin if quicker drying is needed.
Again, thanks for the help with this.
-dk-

I thought of stressing the general idea about Japan Driers:

Japan Driers ARE NOT oil painting mediums nor suitable for mixing with oil painting mediums or oil paints.
Japan Driers are used mostly in crafts and specialised work, such as bookbinding and GILDING, their chief application is as Gilding Size, or Gilding Adhesive i.e. it "bites" the gold leaf, grabs, because Japan Drier/Japan Size remains tacky precisely for the purpose.
Japan Drier/Japan Size is very useful if you need to apply gold leaf or silver leaf to a DRY layer of oil paint.

An example:

In 16th and 17th centuries Spanish and Portuguese portraits made for the Nobility and Ecclesiastical Authorities, it was common practice to include the person's Coat-of-Arms, usually in the top leaf corner of the portrait. Normally the coat-of-arms is ornamented with a "coronet" or a "crown", depending on the rank, there duke's crowns, count's and baron's crowns, etc... Crowns were represented in peinting in their local colour, that is, gold or silver or platinum. The artist would make the design of the crown and paint its elements with the Japan Size, then the metal leaf applied over when tacky, the unnecessary bits brushed off, so the crown would look perfectly designed. The crown would be then glazed with transparent colour to give it shades and light.

In Heraldic Art (the art of designing coats-of-arms) Japan Drier is also used by illustrators when such designs are to be completed in translucent oils, although in modern times, more and more Heraldry Artists now use Acrylic paints, design gouache and Illustrator Inks.

Luis Guerreiro
04-13-2002, 04:56 AM
LEAD & MANGANESE SICCATIVES

We have seen that the advantage of LEAD and MANGANESE siccatives compared to Cobalt is that Lead and Manganese dry the oil painting film from the inside out .
Of these, there have been some famous driers:

1. Siccatif of Harleem
2. Siccatif of Courtrai

Siccatives of Harleem have been discarded for a long time, because they were very dark and would tend to yellow and darken the picture.

Modern industrial practices have enhanced the methods of making Siccatif of Courtrai
There are 2 types of Courtrai Drier:

TYPE 1: Contains both Manganese and Lead salts and is the most powerful drier. Darker in colour, but modern industrial processes have managed to stop it from darkening pictures.

TYPE 2: Contains just Lead salts. Clear transparent it is not so powerful as type 1, but safer as it is safer to use with light colours or colours in which even a slight yellowing could pose problems.

The BEST Courtrai driers I ever experimented with and indeed used are manufactured by LeFranc & Bourgeois :

Product Ref. Code 1168 - Brown Courtrai Drier
Contains manganese and lead oxides

Product Ref. Code 3122 - White Courtrai Drier
Contains only lead oxides

MAXIMUM APPLICATION RATE: 1% to 5%, which means 2 to 3 drops of drier for a blob of oil paint of the size of a walnut.

These driers should be used only with slow drying colours, especially Brown Courtrai Drier. White Courtrai Drier may be used in the same proportions mixed in the painting medium.

Brad121
12-10-2005, 10:00 AM
Has anyone used OIL COLOUR JAPAN GOLD SIZE as a siccative with oil colour perhaps in alla prima so as to be able to add another colour without bleeding of the pigments to the lower level?

Success stories?

Brad

Einion
12-11-2005, 04:42 PM
Hi Brad, if you want your work to last in good condition I wouldn't get into the habit of using added metallic driers. If you really want to use them I would strongly recommend you mix them in controlled amounts to a medium*, not directly with the paint as it's all too easy to add too much unless you're using large volumes of paint.

*A medium you would be using anyway, not for this express purpose.

...perhaps in alla prima so as to be able to add another colour without bleeding of the pigments to the lower level?In alla prima work there's technically no lower level except the primer, what are you seeing exactly?

Einion

Brad121
12-11-2005, 07:48 PM
I just meant in alla prima in laying one colour above another, and not mixing them in the process.

Thanks for your reply...

brad

PaoloGerero
07-12-2011, 03:45 AM
Do these driers make the paint layer kind of... hard, eggshell-like and crackly?

Danny van Ryswyk
07-12-2011, 04:54 AM
Lead Naphthenate, like Luis said; dries the oil painting film from the inside out. http://naturalpigments.com/detail.asp?REFERER=artiscreation&PRODUCT_ID=500-31MED018
Or you can use an oil that is cooked with lead, like James Groves 'Walnut Black Oil'. http://www.jamescgroves.com/mediums.htm

Termini.
07-12-2011, 05:57 AM
Do these driers make the paint layer kind of... hard, eggshell-like and crackly?

Driers don't necessarily make an oil paint film egg-shell like and crackly. I think that you may be looking at very old paint films, and are attracted to the present appearance. They may not have looked that way for decades, or even a century of more after they were painted. The effect you are after may be better obtained with the use of acrylics, and the various matte mediums, and crackle mediums, which do wonders to create an egg shell like finish, with even old appearing cracks. Jo Sonja acrylics appear very simialar to egg tempera, which is known to create an eggshell type finish. The paint on the examples you looked at could also have been oil-egg emulsions, or any number of things.

If you want a more matte effect to your oil paint, you could get some wax (Gamblin makes a good product), and add a small amount to your paint. Oil paint will cure to a very hard surface, but if it is thick, it can take a year, or years for it to harden.

If you are familar with mulling your own paint, you could also get some glass beads http://kremerpigments.com/shopus/index.php?cat=01050103&lang=ENG&product=59822 , and mull them into cold pressed linseed oil, forming a very thick sort of paste. It should be mulled very well, so that although it is thick, it is not gritty. This material has to be dispersed and each particle encapsulated with oil, as one would do with a paint. When complete, a small amount of this can be added to oil paint, to create a very hard, more matte effect, yet appears very translucent.

As Danny mentioned, a leaded oil is good material as well, for making a tough durable surface. I have found this version to be excellent:http://kremerpigments.com/shopus/index.php?cat=0604&lang=ENG&product=79097

Again, although this is the oil forum, your problem may very well be solved by moving to a different medium http://www.jerrysartarama.com/discount-art-supplies/Acrylic-Paints-and-Mediums/Chroma-Acrylics-and-Mediums/Jo-Sonjas-Artists-Colours-Sampler-Set.htm?gclid=CI6d6cDE-6kCFdBrKgodhDFPYg

and maybe the addition of somethings such as http://www.goldenpaints.com/technicaldata/crcklpst.php

Good luck

Oh, and where did Luis go, haven't seen him here in years?

Adriantmax
07-12-2011, 12:19 PM
A lot of illustrators that still use oil paint add some cobalt driers to their solvent since it's easier to dilute it in small amounts whilst making sure it gets into all the paint.

Freesail
07-12-2011, 05:14 PM
I used Japan dryer 41 years ago as a very young teenager to speed up the drying of the paint. About a week ago I saw two of my painting from back then, both were in perfect condition. Neither showed any signs of age or cracking.