First Time Out with Spray Finish
A beginner gets advice on spraying pre-catalyzed finishes. March 2, 2006
Question
I have done mostly hand finishes in the past and now am going to try a spray finish on a table made out of antique cypress. Before I mess up the table I spent many hours building, I thought it would be wise to get some advice. My plan is to seal the table with a SW pre-cat lacquer, lightly sand it, then glaze it with a SW Van Dyke Brown glaze. Then put several topcoats of the SW lacquer on. Is this a good plan?
Forum Responses
(Finishing Forum)
From contributor D:
If you are going to use the precat as your first coat and then after glazing you will be topcoating using ordinary lacquer, I see the potential for the topcoat wrinkling your first coat. You can do a simple glaze sandwich using a precat finish system. If you are using all Sherwin-Williams products, call your nearest Sherwin-Williams commercial coatings supplier. This is not your paint and wallpaper outlet. Ask the people in the commercial coatings division to outline a finish schedule for you using your precat and glaze.
From the original questioner:
I am actually using the pre-cat lacquer for the topcoat also. The process I described is what the local SW salesman at the commercial coatings store told me to do. But he was a young man and I wanted to make sure he was steering me in the right direction. Thanks for your advice.
From contributor V:
I mainly use the SW precat lacquers (acrylic conversion coating). It's great stuff. If you're going to use it as a sealer, reduce it 50% with lacquer thinner. It will make it much easier to sand smooth all the dust nibs you will get. For a large table top, I recommend picking up some MAK from SW and adding about 3-5% in the precat. It will help self-level better and reduce your chances for overspray.
From contributor D:
The people who staff the commercial divisions are properly trained. They want to sell you things that work for you so that you can buy again and again. They want your business and, therefore, they want your successes.
When you are doing glaze, the thing you need to be especially concerned with is thick accumulation of the glaze. An area of glaze that is too thick can create an intercoat adhesion issue. That is one of the reasons that you have to work the glaze. The other reason that you work the glaze is looks and aesthetics and that all comes down to you and your techniques.
Follow the tech sheet for the glaze. Follow the SW person's advice for how to use the stuff. Pay attention to your times and glaze recoat windows. Glazes have open times during which they can be shot and locked into place. Miss that open time and you have to wait for the glaze to go through a complete cure cycle.
From contributor S:
After glazing, allow to dry (24-36 hours) or until the glaze will not rub off when rubbing with your finger. For table tops, I like to use conversion varnish because it contains more solids and it is more resistant to H2O, heat and chemicals. Use vinyl sealer (catalyzed) before and after glazing - this will eliminate any wrinkling or lifting. Ask about this technique at SW and I believe they will agree.
From Paul Snyder, forum technical advisor:
Do you have any experience spraying or have someone that can help you learn? Like all skills, spraying takes practice to get good. I'm wondering if this is the best project to experiment on?
In addition to the normal problems of learning spraying like avoiding dry spray, over-spray, stripes, orange peel, runs, sags, solvent pop, blushing, etc., you're also adding a glazing step. So you need to spray well, avoiding the normal problems, apply the glaze correctly, avoid re-coat windows, and stay within the recommended maximum dry film thickness for the catalyzed finish you choose. Not to mention proper sanding between coats while avoiding cutting through the glaze.
When I teach apprentice finishers how to spray, I start with the really easy stuff to give them a chance to practice their basic spray techniques (patterns, triggering, overlap, distance to surface, etc.). I'd never give this project to someone who wasn't already good with the spray gun and had done some glazing, even if I was watching every step they made.
From the original questioner:
I do not have any experience spraying with a gun. I have a brand new gun that I am trying for the first time. I plan to experiment and practice on some plywood before trying to finish the table. I also have a friend who has experience and plan to watch him at his shop for a day or so. I did not realize the problems that are associated with a glaze. Is there a book or some other resource you would recommend? I appreciate your concern and your words of caution.
From Paul Snyder, forum technical advisor:
I wouldn't say you need a book or other reference, just some practice/experience. You know what you want to do and the steps to get there, you just need to develop your skills. There's no substitute for hands on experience. I can watch a heart surgeon, but that's not going to get me into the operating room with a scalpel. ;) Spraying isn't nearly so technical, but it does take practice.
From the original questioner:
I finished the table this weekend. I went with a vinyl sealer followed by a glaze, followed by another coat of sealer and then two coats of the lacquer. I think it turned out nice, especially for my first time with the sprayer. Thank you all for the advice.
From Paul Snyder, forum technical advisor:
That's impressive. Glad to hear the good news!
