View Full Version : Varnish questions
09-21-2009, 10:13 AM
I've looked over two threads about varnish and I have the article bookmarked now from on here but I still have a few questions. I'm currently working on my first oil painting in several years. My last oil paintings were done in high school and my teachers never mentioned varnish so it's all new to me. So anyway; I keep seeing waiting times between finished painting and varnish coat varying between 6 months and a year. I like the suggestion someone had of selling the painting after it was finished but offered to have it brought back for a coat of varnish after a year. Still though wouldn't that turn off some buyers? Also just because I've never looked into it why can't you just wait a few days or weeks and then do the varnish? Another big question for me is simply are there any wm varnishes, since I'm working in wm oils I'm really not looking for something that would require all of those solvents also in the middle of winter going outside to get ventilation while I work is not very comfortable.
09-21-2009, 03:47 PM
Hi Jessica! W&N makes a wm varnish David compiled some great information regarding this product here: http://www.wetcanvas.com/forums/showthread.php?t=577277
I use an intermediate varnish which I can usually put on after 3 or 4 weeks. I then scribble on the frame the letters IV then the letter V with a month detailing when the final varnish can be put on. I also have a little certificate to go on the back notifying a purchaser of copyright and explaining the letters. It's up to them if they want me to do the final varnish or somewhere else.
PS. Have the painting lying flat when you varnish it. I varnished one huge painting when I'd hung it. The varnish ran down in loops and I've never been able to disguise it.
09-22-2009, 11:07 AM
...have it brought back for a coat of varnish after a year. Still though wouldn't that turn off some buyers? Also just because I've never looked into it why can't you just wait a few days or weeks and then do the varnish?
The reason for waiting is to allow enough time for the oils to cure and the oil surface needs to be exposed to air in order to do that. This typically takes anywhere from 6-12 months, but may be slightly less depending on what you painted with and how it was applied. Even with alkyds it's 2-3 months. Six months is the safest general time period, more for very thick paint layers.
A recommended test is to use a small amount of solvent (not water in this case but turpentine or mineral spirits if it's a spirit based varnish) on a cotton swab on the most recent layer of paint that you can sacrifice and see if any pigment comes off. I'm not convinced that's best since other areas may still be curing. Another test is to press your fingernail into the thickest layer and see how hard it is. Both sound rather "iffy."
Retouch varnishes can be applied within 1-2 weeks after the last layer is painted. They offer temporary protection until the final varnish, which can be professionally applied later by anyone who knows what they're doing.
...Another big question for me is simply are there any wm varnishes, since I'm working in wm oils I'm really not looking for something that would require all of those solvents also in the middle of winter going outside to get ventilation while I work is not very comfortable.
I still haven't tested out W&N water miscible varnish, so I can't say how well it works. That's the only one I know of on the market. The only other alternatives I can think of are brands of citrus solvent varnishes, but they have their own issues to deal with, and you may find them no better than the traditional options.
09-23-2009, 05:33 PM
Thank you for asking my question for me! I will read all the data cited.
09-23-2009, 10:14 PM
From most of the sources I have read, the 6 months to a year estimate is very conservative. If you paint in thin layers, and not much (or no extra) oil, it can be ready to varnish considerably earlier.
From the Gamblin website: Some paintings are dry enough to varnish after two weeks. Some are not ready for two years. If you paint thinly with fast drying colors and use a fast drying medium, in a warm and dry climate, then the painting may be ready to varnish in two weeks. But if you painted using Alizarin Crimson to make a half inch thick layer using poppy oil as a medium then the painting may not be ready to varnish in two years, if ever!
How to tell if a painting is ready to varnish is easy—just touch it. If there are impasto areas, gently press your fingernail into that impasto. If it is firm underneath the surface of the painting then it is ready for varnishing.
Also keep in mind that varnishing is a choice not a requirement. Many painters do not varnish at all, or only if the painting's finish is not at the desired level of gloss or evenness, or to help revive sunken areas.
09-24-2009, 12:03 AM
You may be correct, Don, however it's not a bad idea to ere of the side of caution. If you check out this Winsor & Newton page (http://www.winsornewton.com/main.aspx?PageID=406), they say: "Don't varnish too early, even the thinnest oil painting should be allowed to dry for 6 months." I think using a retouch varnish in the meantime is the safest route.
It's true that some painters do not varnish, but I would question their motives. It may just be that they don't want to be bothered with it, or can't apply it properly.
09-24-2009, 08:47 AM
The one thing that made me want to varnish my paintings was I saw something about protecting the colors in the painting. I've been painting in rather thin layers too, some them were drying over night. I don't use any extra oil medium at all either. So I think at most I'd be ok with just 6 months.
09-24-2009, 11:49 AM
As far as I know only some mineral spirit based varnishes contain stabilizers that protect against light UV ray penetration. I don't believe the Artisan varnish has this, and I've never heard of any damar varnish that does either.
09-24-2009, 12:37 PM
Hmmm... now I think I'm a bit more confused. I've done a bit of shopping around and have found a few options that offer UV protection, and I've seen a few that come in a spray can. I already have a fixative that I use for my drawings, and I'm more familiar with how those spray. So I'm leaning more toward trying one of those, unless of course the reason why I'm seeing a lot about people using the type you brush on is because you have a better finish/protection to the painting with that type.
09-24-2009, 05:48 PM
actually I rarely varnish my paintings because I don't like the way it looks, but thats just personal preference, when I do varnish i wait a good 6 months for the paint to cure properly.
The problem is that oil paints (even WM oils) dry by oxidisation, and varnishing creates an air tight layer over the painting depriving the oil of the oxygen it needs to finish curing properly.
I have heard of paintings actually becoming tacky several years later due to varnish being put on too early allowing the undried paint to react with the varnish over time, I've not experienced this myself, but I'm not willing to risk it either
09-25-2009, 12:24 PM
...spray can...So I'm leaning more toward trying one of those, unless of course the reason why I'm seeing a lot about people using the type you brush on is because you have a better finish/protection to the painting with that type.
I can't recommend using a spray can for varnishing myself. It's too awkward to apply evenly. I prefer using a good varnish brush.
If you've not varnished before my procedure is as follows:
(Work in a warm, dry, dust free area)
1> Lay the painting flat and remove as much surface dust as possible.
2> Pour your varnish into a large can or bowl and diluted as necessary. I typically dilute by @1/3 volume of varnish.
3> Load your brush and press to the sides of the can so that it doesn't drip.
4> Start in one corner and varnish a section with as much as your brush will cover, applying your strokes side to side. If you set up the painting opposite a light source, the glare can help you see the varnish better. If it's a large painting, reload your brush again and overlap your sections as you cover the whole surface. Don't worry too much about getting it even at this point, but work quickly. If it starts to pull on your brush, the varnish is setting up and you're working too slowly.
5> Once you've got the whole area covered, go back with a dry brush (I use a new brush for this) and stroke evenly in perpendicular strokes to how you applied the varnish until you no longer see any brushmarks. Wipe your brush dry after each stroke.
6> Set the finished painting aside to dry overnight. Either lean it facing a wall or hang it in a dust free location. Afterwards, examine the surface for any uneven sheen that may require another coat.
Pick up a few cheap canvas boards to practice on. You don't need to wait several months since you're only practicing, but I would wait at least a week or so so the solvent doesn't remove paint. Paint them with thin dark colors so you can see the varnish more clearly.
09-25-2009, 02:31 PM
If varnish is applied too soon (before at least that ubiquitous 6 months), and depending upon storage conditions of the painting once varnished, paint may crack as the varnish layer is pulled towards the cured and uncured areas of paint at a different rate. This can also cause surface mottling and wrinkling. Blooms of discoloration may also appear beneath the varnish.
09-28-2009, 11:14 AM
I think I'll wait the 6 months before varnishing, I don't paint that thick so the 6 months should be good enough. I'll definitely have to pick up some varnish and brushes rather than the spray can. I have one of those canvas panels that I started a painting on but I wasn't happy with the surface so I moved on to a new painting on canvas. I'll use that to test out the varnish. It's been a few months but definitely not 6. The painting is no good anyway so it really won't matter if it cracks.
01-08-2010, 07:02 PM
In my mixed medium painting class, there was a woman that always worked in acrylic, but it seemed to me that the style of painting would have looked better in oils. I asked her about it, and she told me that her first two paintings were in oils. She waited a full six months before varnishing them. Both of her oil paintings were ruined--the paint still wasn't completely dry. She said she would never paint in oils again.
Believe me when I say that I will be waiting more than six months before I varnish my painintgs.
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