Final varnish

[Claudemir Bonfim]

I was missing your comments here Richard.

I prefer to use a mix of gloss and mate varnish, what about you?


Ps. I have never had my car "egged".

[Richard Bingham]

I'm awfully old-fashioned. I use a 6:4 mixture of damar and mastic, I make up the varhishes in the studio using good turpentine and the best quality resins at a 5# cut (proportions: five pounds of resin to a gallon of turpentine)

This mixture is easier to manipulate than damar alone. I apply the varnish with a 2" badger sash brush and "lay off" the surface with the tip of the brush as the varnish tacks up to eliminate a high gloss.

I've heard a lot of good things lately about Gamvar, which is a synthetic varnish (I believe methylacrylate resin). The resin is dissolved in mineral spirits, and is reported to remain dependably water clear over time, as well as readily removable in MS indefinitely. It sounds good, but I haven't tried it yet myself . . . mostly because I don't see a pressing need to replace a method I've found suitable. Those who have tried it report that it doesn't lend itself to manipulation in application, so what you see is what you get!

I'm glad you haven't been "egged" ! (Maybe vandals in Brazil have better sense?)

[Jennifer Bogartz]

Richard, thank you very much for your insight. You mentioned that artists can run their own tests on materials. How would I go about testing the materials I'm using? I am currently using walnut oil, walnut/alkyd oil, and liquin as medium (not all at once). I've heard some negative things about alkyds and liquin such as delamination and have not worked with them long enough to see those kinds of problems in my work. I'm in the process of researching varnish and can see the benefit of testing the material before committing to it. Does an artist need to try many different mediums and varnishes in order to become well acquainted with them?

[Claudemir Bonfim]

Originally Posted by Richard Bingham

I'm glad you haven't been "egged" ! (Maybe vandals in Brazil have better sense?)

Well, it is not common to have your car attacked by vandals here, in fact, it is very rare, but when it happens during some sort of manifestation, things go really bad.

Well Jennifer, I think Richard will answer your question soon, but meanwhile I'd like to tell you that mediums are something very personal. It depends on your way of working. Some mediums accelerate the drying of paints, others slow down. You should watch Daniel Greene's video "Erin", in this video he addresses this subject in detail.

If you don't have access to the video, we can discuss it here on in another thread.

You mentioned Walnut oil, that's wondeful but adds a lot to the drying time. In my Country people don't have the culture of patience to sit for long sessions, so I use my mix of 1 part of stand oil e 4 parts of odorless mineral spirits, this medium accelerates the drying time. I also use Titanium white of flake white, which get dry a lot faster than zinc white.

You will have to find your own recipe to your medium, but I also avoid the ones with bad reputation.

[Richard Bingham]

Jennifer, for an artist to test materials in the studio, one realizes first off that we don't presume to have a command of either organic chemistry, nor of laboratory grade procedures and equipment.

The first test is quite naturally, one of a simple "hands on" assessment. Does the material "do" what you want it to? Does it handle to your liking?

Tests for permanence are rather more subjective, as there may be a great number of variables which will be out of one's control as soon as a painting leaves your possession. I rely on a rather "dumb brute" method for testing my materials, simply subjecting test samples to outdoor weather. I place test samples of painting supports, paints, mediums, varnishes, etc. outdoors on the weather side of my studio, and leave 'em there. Between exposure to sunlight, temperature variations from -20F to over 100F, rain, snow, hail, sleet and frosts, a pretty good picture of a material's failure modes emerges. Naturally a painting would never be subject to that kind of abuse under normal conditions, but weather provides a semblance of accelerated aging. Naturally, it's not going to cover all the bases.

Learn as much as you can about materials from reading. To keep it very simple, my favorite book on that subject is Frederick Taubes' "Studio Secrets" alas, now out of print. Unlike a number of latter-day self-proclaimed experts on the subject, Taubes was a practising studio artist who based his methods on what is known of traditional "old master" technology, and as an entrepeneur who marketed painting materials and mediums was actively involved "hands on" in his business. He wrote the technical column in American Artist from 1942 until well into the 1950's, and taught materials and methods courses in seminars he gave around the country.

I think every artist who paints in oils should own a copy of Ralph Mayer's "The Artist's Handbook of Materials and Techniques". It contains a lot of sound, basic information, although it is overly ambitious in scope, and suffers from the fact that Mayer was more an "armchair" type who relied heavily on "hearsay" and recapitulating information from other sources as opposed to verifying the book's contents through his own working experience.

Beyond that, discussing materials and methods with your peers is almost always instructive (one way or another) but can be a minefield of errors and incomple information and bad practice. One should have a clear working knowledge of painting materials and procedures and a means for testing all the ideas which abound, rather than blindly following anyone's "prescriptions". It sounds forbiddingly complex, but hey, it's not rocket science, and the basics are very simple. All the complexities are either overlapping redundancies, or extrapolations which can fall back easily upon the knowledge of basic, sound painting practices for clarification.

Since I'm feeling reckless, (read stupid?) I think your questions about mediums would be better addressed in another thread, which I'll open in response to them. Claudemir wisely notes that the subject of painting mediums is one which is very personal with almost everyone who paints in oils, and has caused some dandy knock-down-drag-out flame wars on art fora as well as in person, when artists meet.

[David Clemons]

Originally Posted by Richard Bingham:
...Marcus, the principle is correct, but you have it reversed. As paint films continue to dry and give up their volatiles, they shrink They do NOT "grow"...

While I wouldn't refer to it as growing, from what I've read drying oils do expand, possibly as much as 15-25% as they absorb oxygen, and then will gradually lose volume as they release their volatile content over time. This can lead to cracking issues on a top layer surface which itself has already dried. The volatiles which may include acids and alkenes can also stay present in the paint film and react with some types of pigments, which may lead to discoloring with any top layers as well.

[Richard Bingham]

Originally Posted by David Clemons

. . . from what I've read drying oils do expand, possibly as much as 15-25% as they absorb oxygen . . .

Try this experiment. Put just enough linseed oil in a palette cup to cover the bottom of the cup, and "pull up" visibly on the sides (that would be about 1/16" "deep"). Leave it in a warm, well-ventilated place (plenty of oxygen). At what point do you note expansion of the volume of oil by as much as 10%? What is the nature of the surface of the dry oil film as soon as the puddle of oil "skins over" ? Is it bloated, like a little bubble because of the volume of oxygen being absorbed, or does it resemble a raisin, shrinking in the sun from the loss of its liquid components through evaporation?

When linseed oil is heated to approx 475F in a vacuum in making stand oil, there is a slight noticeable increase in volume, as the purpose is to partially polymerize the oil, which requires the addition of oxygen, but that's not a dry film state.

[Jennifer Bogartz]

Richard, I couldn't find Frederick Taubes' "Studio Secrets" at my library but they did have a couple other of his books, both on oil painting, and I put them on hold along with Ralph Mayer's book.

[Richard Bingham]

Jennifer, try Abe Books online for books out of print. I was able to "score" a couple of copies of "Studio Secrets" for my students very reasonably a few months ago!

[Clayton J. Beck III]

Originally Posted by Marcus Lim

... the actual fact is the painting is still 'growing' inside the painting.

Originally Posted by Richard Bingham

Marcus, the principle is correct, but you have it reversed. As paint films continue to dry and give up their volatiles, they shrink They do NOT "grow".

At the risk of an omelet on my Buick ... You are actually both right. In the beginning, the drying paint film gains weight as oxidation means absorption of oxygen molecules, then as the chemical reactions release gases, the paint looses mass.

I am not a chemist but that is the way I learned it.