I do an old style of German decorative painting called Bauernmalerei. Originally it was done in oil paints, but now most folks who do this use the acrylic paints that are sold in craft stores. After doing a painting, the current books on Bauernmalerei recommend using only varnishes that are sold in craft stores. I don’t know anything about them, except that they are not polyurathane. These books give STRONG warnings against using the types of varnish or lacquer that are sold in Home Depot and woodworking stores (eg Minwax polyurathane). I have read that two problems occur. One is a severe yellowing, which is not wanted. The other is that these products will not adhere to the acrylic paints.
I am about to make and paint a very large schrank (German style cabinet which serves as a closet). I do not want to buy a hundred small bottles of “craft varnish” to put over the painting. What is the truth about using modern varnishes or lacquers or even shellac over acrylic craft paints??? I would rather not use shellac as the final coat, but rather something more durable. I would appreciate any practical advice about what to do. I certainly don’t want to build and paint a giant schrank, only to have the clear finish ruin the decorative painting.
Thank you.
Replies
You might need to spray a coat of shellac over the paint and then apply a coat of waterborne varnish which will not yellow. The polyurethanes will yellow as will non-poly varnishes. Have no idea what the craft varnishes are unless they are waterborne.
You should contact the manufacturer of your acrylic paints. They will likely be able to give you good information about finishes compatible with them.
To do it yourself, go to the craft store and get one little bottle of their varnish. Then go to the HD and buy something that seems comparable.
Use some of your acrylic paint and cover some boards as though they were pieces of your artwork. Then finish the boards with the various products. You might try Gretchen's idea of a shellac first coat, too.
The problem with this method is, you won't necessarily discover a problem that doesn't show up for, say, several years (though you can stress the boards by putting them in direct sunlight for several days). Contacting the manufacturer of the paints is going to be best, or seek out fellow artists for their ideas. They needn't do Baurnmalerei, plenty of artists do durable work in acrylic on wood.
John D.
I took your advice and called the company that makes Delta Ceramcoat. The person I talked to had faced the same situation and tried a number of different things. Shellac didn't adhere to the acrylic paint well. Waterbased varnishes such as those from Minwax did adhere but discolored the light colors of paint. She recommended using an "acrylic based" varnish such as that made by Delta or another company, named "JW". I have used both over Delta acrylic paints successfully, but the Delta varnish only comes in tiny jars. The JW varnish comes in pints, quarts and gallons, so I am all set. I will use the JW brand. Although Delta does not manufacture the JW brand, the lady was nice enough to give me ####phone number where I can purchase the larger containers of JW varnish.
Problem solved, thanks to your suggestion.
Thank you very much.
Mel
I've got to wonder about that advise, particularly that which said that shellac didn't adhere well to the acrylic. Shellac adheres to pretty much anything except silicone. Shellac, in a light colored form, super blonde, will have little impact on color, and will not darken significantly over time.
Totally agree. Marketing?Gretchen
Probably weak training of customer service reps. What do you expect at $7 an hour.
>> Shellac adheres to pretty much anything except silicone.
Not sure if you meant that Steve. Shellac is the standard barrier coat between silicone contaminated surfaces and final top coats.
As a friend said one time, "Shellac will stick to anything, including peanut butter". He had applied shellac over a stain left by the peanut oil when a child wiped his sandwich on a surface about to be finished. I've never tried it on peanut butter so don't put a lot of stock in that.
I would also add that a clear waterborne acrylic should work just fine. I used a Minwax Polycrylic on a white acrylic painted surface a couple of years ago. It went on water clear and remains today with no amber cast. Of course there are some waterborne acrylics that have had some amber dye added to provide some grain highlighting. Mostly though, I've seen this in waterborne floor finishes.
Howie.........
Edited 5/9/2006 12:29 pm ET by HowardAcheson
Edited 5/9/2006 12:30 pm ET by HowardAcheson
Well, sort of. Yes, it is the standard barrier coat, as I recommended in another recent thread, but the first step of using that method is to remove all the silicone that is possible with thinner, etc. first. And it is best to spray a dry coat before a wet one, or even shellac can crater over heavy silicone. I saw that the hard way once. (Don't let marine silicone spray get on interior brightwork around the engine box. DAMHIKT)
But it does adhere well. There are certainly reports in the conservation literature of shellac coating layers over layers of almost solid wax.
Have made seven or eight of this style of chest. Originals (at least those made in this country) were painted with red lead, white lead, lampblack, prussian blue, etc. All homemade, of course. Watch out for the acrylic paint for this project. Just does'nt look right. Learned this the hard way. I've found regular latex gives a much more natural result. (though originally the chests were very bright and bold) Easier to "age" also. Guess you know that the decorations all meant something. See Southern Furniture 1680-1830 the Colonial Williamsburg Collection, by Ronald Hurst, pp334-343, an unbelievable wealth of information for your shrank. Covered the first chest with poly and it worked fine. No adhesion or yellowing. Just did'nt look right though. Now I just use shellac. Jimmy
This forum post is now archived. Commenting has been disabled