Glazing and Conversion Varnish

Advice for a first-timer on glazing with conversion varnishes. March 9, 2010

Question
I have no experience with glazing. I have a vanity to make and I think this would be the perfect job to learn. My customer has picked an almond color with brown glaze. Most times I outsource the doors and drawer fronts. I can get pigmented SW conversion varnish from a retail SW store. What are the correct steps? Should I use vinyl sealer? I'm quite sure the door company uses the finish as a sealer. Do I glaze over pigmented topcoat and then clear coat? I know there is a max number of coats you are supposed to use. Any advice will be greatly appreciated.

Forum Responses
(Finishing Forum)
From contributor D:
Your glaze coat should be sandwiched in between layers of vinyl sealer. The alternative is to use a spray-powder glaze like ML Campbell's Amazing Glaze. The Amazing Glaze can be layered in between your coats of conversion varnish (pigmented color coat with a non-yellowing clear topcoat in the sheen you want).



From contributor K:
This being your first time, I cannot stress enough how important it is for you to do your due diligence and make a test piece first. Scratch test your test piece. Glazing with conversion varnish is a different ballgame than glazing with a lacquer. Do it wrong, and your finish might fall onto the floor.

Because you mentioned Sherwin Williams, I will volunteer our finishing sequence for a pigmented conversion varnish with glaze, using Sherwin Williams products.

1) You can use a primer if you want to. Because we do so many colors other than white, we've gotten away from using primers. If you do, the recommended primer for use under SW conversion varnishes is their Kemvar Primer Surfacer.

2) Apply 2 to 3 coats of your color, depending on whether you used a primer or not. Scuff sand between coats of course.

3) Clear coat with your choice of Sherwin Williams conversion varnish; we prefer V84 FH130 Catalyzed Acrylic Varnish.

4) Glaze. Two very important points here. A) Make sure you use the new Kemvar Glaze; it has been formulated to work with conversion varnish finishes. B) Apply the glaze as soon as the finish is dry to the touch. I would not wait longer than about 3 hours, but within about 1 hour is best. This is critical if you are going to use anything but the new Kemvar glaze. The finish has to be soft enough for the glaze to bite, or you will have adhesion failure. The Kemvar glaze is slightly better at extending this window of time, but I would still use the 1 hour window if possible.

5) Apply topcoat. Important! Apply this topcoat almost as soon as you put down the glaze rag/brush. This is effectively your glaze sandwich; a non-cured base coat, followed by the glaze, followed by the next clear coat. These steps must be done in quick succession. Note: this is not what is recommended on the data sheet. Don't believe the data sheet.

6) Scuff sand and apply your final clear coat.



From contributor A:
What is used for coloring wood - pigmented CV or lacquer? Turns out my local SW store no longer carries one gallon cans of pigmented CV, but they do have pigmented lacquer.


From contributor K:
Pigmented lacquer will work just fine. Obviously, it doesn't have quite the same durability, and it's possible that it may take an additional coat to get the coverage you want. If you do use lacquer as your pigmented coat, I would use a CAB acrylic lacquer in place of the CAB acrylic varnish I stated in my earlier post.


From contributor V:
But whatever you do, do not spray clear CV over the pigmented lacquer and glaze. In case you didn't already know that.


From contributor M:
ML Campbell has a new glaze that does not have to be sandwiched between vinyl sealer. It's called Vintage Glaze. You should check it out. Also, regarding the supply or quality of ML Campbell products, I have had no problems in Massachusetts.