Retouch Varnish Question

[Karin Lindhagen]

What a relief to learn that more people than I have this problem with retouch varnish that will not dry. For some reason, the first layers seem to dry much more slowly than the last ones on the same painting. The last layers will generally dry in a week, while the first layers might take several months. But next time, I will try the advice to heat up the room. In order to avoid dust I often leave the paintings to dry in a unheated room that is not being used. That might just be the problem!

Every now and then I paint the next layer even though the retouch varnish is not quite dry yet, and after a while it is hard to tell wether it is the paint or the varnish that is not drying. But I do believe the varnish is to blame, really.

Not long ago I made the mistake of applying the next layer of retouch varnish before the last layer of paint was quite dry. Disaster! All the turp in the retouch varnish made the last layer of paint dissolve into some kind of mist-looking mess. Thank heavens the client was a sweet man, full of confidence that I would sort it all out during the next painting session...

[Michele Rushworth]

In order to avoid dust...

One way to minimize this problem is to lean the painting against the wall, facing the wall, as it's drying. That way its surface is slightly tilted down and away from whatever dust is circulating around the room. Do this only after the varnish has set somewhat, or it will run down the painting. Leave the painting flat for a while, depending on how runny the varnish is, and then after a while, lean it against the wall.

[Peggy Baumgaertner]

I'm a little late to this ball game, but wanted to toss in another angle. No one has mentioned the ground, which is where I've had tackiness problems.

If you buy a pre-gessoed canvas and you get the end of the roll, sometimes you can get a pooling of oiliness. It almost looks like big blotches of linseed oil have dripped on the canvas. It is impossible to see these oily areas until you have started the painting. They are visible because the paint dries extremely slowly and in a semi-oval pattern. (The first time I encountered this, It was on a Governor's portrait...not where you want to get a trial by fire like this one...).

The paint took over a year to dry into these areas, and dried in a tree-ring pattern, working from the outside in.

Now that I have spotted this defect, I've been able to see it in others canvases. You can "fix" it when you recognize it by rubbing the surface with mineral spirits before you start painting, removing all the excess dried linseed oil from the surface.

Unfortunately, if you have already finished the painting, it cannot be fixed. I ended up scraping the Governors portrait, and starting again. (...and yes, it had already been delivered...)

BTW, I've been using a variety of retouch varnishes over the past 22 years, and have never had a problem with tackiness that you describe. The primary problems with retouch, is if you apply it on fresh paint (paint less than a day old), the retouch varnish can cause your painting to dissolve and run down the canvas. If you use too much retouch varnish too often on the canvas, the surface become hard and brittle. I've never had a problem with tackiness that could be attributed to retouch varnish.

[Janel Maples]

Thank you for the warning, Peggy.

This may sound like a stupid question, but is this problem only for an oil primed support? You mention the "fix" by getting rid of the excess dried linseed oil in the pre-gessoed canvas but before I safely assume that this doesn't happen with acrylic primed I thought I should ask.

Thanks, for figuring this out for us, but sorry you had to find out the hard way. I guess a positive way to look at it is you probably have saved many future portraits because of it.

If that makes you feel any better.

??