Poly vs Lacquer

[crokett]

Are these interchangeable as far as the types of finishes they will go over? I have both in my cabinet and am just wondering what to use when.

I did some checking and don't see much on what you can use them over. Most of what I've found says Lacquer is easier to repair but not as durable and most lacquers can water spot. Poly is much more durable but you basically need to refinish the entire piece to repair any damage.

[cabinetman]

Without going into a lot of detail, you can put poly over most any finish, but lacquer not over oil based varnish or poly. I have applied lacquer sanding sealer over oil based stains, with a lacquer topcoat.
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[crokett]

Thanks Mike

Is there a reason to choose one over the other for a particular project other than how the project will be used? Or is it that some folks prefer working with lacquer and some prefer poly?

[cabinetman]

Thanks Mike

Is there a reason to choose one over the other for a particular project other than how the project will be used? Or is it that some folks prefer working with lacquer and some prefer poly?

The choice may be more about time involved. Poly (any oil base varnish or urethane for that matter) takes a long time to cure. Depending on the thickness of the application and the ambient temperature and RH, it could be one or a couple of days or longer to completely cure. There's a difference in "dry-to-the-touch" and cured.

Lacquer for the most part is dry to the touch pretty quick and could cure in an hour or two, depending on the type of lacquer and amount of retarder added.

IMO, polyurethane may be more durable in the long run, for high use areas. It's a close race. For ease of application, Lacquer can be sprayed, or brushed. But I have sprayed varnishes and polyurethanes, and it takes diligence to get good coverage without having it run or apply too much. It's very heavy bodied, and thinning for spraying even makes it more difficult to control because it doesn't flash off very fast. Wiping on or brushing on is usually what I get into with poly. It's easy to apply.

So, the choice may be time, or could be ease of repair, or refinishing. For some applications lacquer seem to be the perfect choice, and then there are others that scream poly.

I'm gettin' more into the waterbased polyurethanes in lieu of either poly's or lacquers. I get as good a finish with a lot less hassle, smell, toxic exposure, and clean up is a snap. For as fast as WB dries, it's a better choice for me as it doesn't really get affected by the humidity changes here.
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[JimD]

I like a water based pre-cat lacquer named Resisthane. It can be applied over nearly any other finish that is completely dried. I get it from Hood finishing products. It is about $30/gallon. It dries in an hour, sprays easily, is rated for kitchen cabinets so its pretty tough. Each coat is thinner than poly so you probably need to use more coats but when it's an hour between coats it's easier to get more coats on. It is crystal clear.

I also like wipe on poly. I thin regular oil based poly about 1/3 with mineral spirits. It has an amber color - like oil based poly always has. The advantage of the wipe-on is ease of application. You also need more coats since it is thin. I normally just use a paper towel for application. A lint free cloth would be better but it doesn't seem to make a big difference.

Jim