I recently watched a painter violate all the rules of finishing that I have adhered to over the years. He put a glaze finish on cabinets and without letting it dry sprayed it with lacquer! He claimed the lacquer would dry the oil and he would not have adhesion problems.
He claimed his glaze was a mixture of linseed oil, mineral spirits and colorant. His stated procedure was to put 2 coats of 60 sheen precatalyzed lacquer on the wood. He would then brush on a coat of the oil glaze to color and highlight or darken areas of the cabinet door. Immediately after he had the look he wanted he would spray the cabinet door with another coat of lacquer.
Later after all the doors in the kitchen were complete he would plan on coming back and applying an additional coat of precat of the sheen desired, in this case 20 sheen. He stated he used 60 sheen because he felt it had more solids and more build. On checking the spec’s this does not appear to be true.
I have tried modifications of this procedure on small samples with success. I applied oil based stain on raw wood and/or conditioned wood and then immediately sprayed with lacquer. I got good adhesion on several attempts. Finally, I tried the linseed oil glaze on a lacquered surface. My results were not good. The lacquer appeared to dry but not really adhere. The lacquer finish could be scraped off easily after 12-16 hours of drying/ The scrapings were oily, unlike normal lacquer.
My procedure was to scuff sand the dry lacquer surface, apply the glaze and then spray with a 10 sheen precat lacquer. The oil glaze at first wanted to bead and not lay flat. I cleaned the surface with lacquer thinner again, sanded again and then sprayed a fresh coat of lacquer. I then was able to get the glaze to spread evenly without it beading up. Finally, I sprayed another coat of the 10 sheen precat. As I said above, the lacquer appeared to dry. However, after 30 minutes or so the lacquer coat, which appeared to be dry, was easily wiped/scraped off. Even after letting it dry over night, the lacquer coat could be scrapped off and the scrappings were oily.
I would really like to be able to use a form of this technique at times. I would like to use it to darken the finish on previously lacquered alder that has faded over time and gone yellow. Stipping all of the wood involved would not be practical. Does anyone have experience with this technique and understand how to make this work? Like I said, this violates all the rules to my way of thinking but I saw it done… Is this a bombshell waiting to go off on the poor contractor or is this really something that will work?
Replies
Dear Steve,
Have done it with oil-base stain as you say and wiped most of it with a rag. Then shoot lacquer and let lacquer dry.
The factor may be the amount of oil that the lacquer is to dissolve. Have not tried linseed, but have used some oil paint dissolved in turpentine and it works. But, again, wipe most off with a rag.
They call it glazing, as you said, and one finishing book makes a statement about the glazing not needing to be totally dry as the thinner in the lacquer will fuse it. But the formal procedure he talks about is to let it dry overnight.
Oil needs to go somewhere and that's into the wood and dry with the air. So, would say it'd have to be a small film for it to be solved and fused with the lacquer.
They may put some Japan dryer on the glaze too, or some other dryer. Also, the coat that the fellow put over the glaze might be heavy on thinner, then he lets that dry for a day or more, as you say. That'd be good for the method, would say.
-mbl-
Thanks for the comment. Your thoughts are kind of like mine. However, that's not what I saw. He applied the oil mixture over 2 coats previous coats lacquer, got a uniform appearance by brushing out the oil and then used an airless to spray lacquer from a 5 gallon tin of lacquer directly over the wet oil. I'm still wondering how he got this to work!
I'd agree with all your concerns, and MBL made excellent observations. I would add that it is possible for the linseed oil based glaze to "dry" under the lacquer through osmosis, as the oil solvents slowly come through the film, but this would take a LONG time, and at great risk. Especially through a cross-linked film (catalyzed lacquer).
I certainly never would have believed it. Good observation about the japan drier in the glaze too. I'd ask the painter if he has a lot of japan drier in the glaze. Its also possible that he may be using a pre-mixed glaze product that already has a ton of japan drier in it, and he may not even realize it. Its definitely a false statement that the lacquer "helps" the glaze to dry - it just skins over it to give the false assumption that its all dry.
I have definitely sprayed Conversion Varnish over not-quite-so-dry oil stain, and didn't have problems, so I guess its possible. I wonder if this painter ever did cross-hatch adhesion tests on this concoction? - JB
"The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)
http://www.pbase.com/dr_dichro http://www.johnblazydesigns.com
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