i need help - Contractor Talk - Professional Construction and Remodeling Forum

cabinet man · 02-06-2008, 12:59 PM

im about ready to finish a set of kitchen cabinets.in the past i would brush on spar urethane to seal cabs i have built.i would like to spray these cabs.so my questions are can i spray spar urethane(of course,right?)and what do i thin it with?what would you recommed i use to seal the cabinets,something water and grease resistant and long lasting at the same time?

DeanV · 02-06-2008, 06:47 PM

I am a little confused with the term "spar urethane." Spar varnish is an exterior finish used on boats and front doors. It is the softest and most flexible kind of varnish which means it will move well with expansion and contraction, but will scratch more easily. I think you want a Polyurethane varnish if you want to brush it out. For spraying, I would look at a good pre-cat lacquer or conversion varnish.

cabinet man · 02-07-2008, 09:11 AM

thx for responding deanv .ididnt know that the spar urethane was so soft ,the only reason i was using it was because i believed it was durable.ive contacted minwax .com with this question and thier suggestion was for me to use thier fast drying polyurethane.iam hesitant to use that product because from what i understand poly yellows over time,and i would like to avoid that but i want a water resistant finish that will last a long time.im not sure what u mean by pre cat lacquer ?pls enlighten me

Thepaintman · 02-07-2008, 04:58 PM

Quote:

Originally Posted by DeanV

I am a little confused with the term "spar urethane." Spar varnish is an exterior finish used on boats and front doors. It is the softest and most flexible kind of varnish which means it will move well with expansion and contraction, but will scratch more easily. I think you want a Polyurethane varnish if you want to brush it out. For spraying, I would look at a good pre-cat lacquer or conversion varnish.

I too suggest lacquer. Then there is also shellac. I do woodworking as a hobby and spray all my projects with shellac and I might add with success. If you are not sure you may want to sub these out to a professional that sprays finishes for a living.

Jerry

**Teetorbilt** · 02-07-2008, 05:10 PM

We finish the panels before installing into the nearly finished rails and stiles, they get the final coats post-assembly. This eliminates the ugliness that can show up when the panels contract. Just a hint for future work.

I'm also confused with the terminology. 'spar' and 'urethane' apply to water and oil based. Which are you planning to use?

**slickshift** · 02-07-2008, 05:49 PM

Must be the Minwax "Spar Urethane" them
It's a urethane, but they call it "Spar" to differentiate it from their regular poly as it's indoor/outdoor-UV-weather-resistant type urethane

Their quick dry urethane will be just fine

Lacquer could be a good alternative also

DeanV · 02-07-2008, 06:38 PM

Pre-cat lacquer is a lacquer that has catalyst mixed in the can (post-cat are when you have to add the catalyst before you spray) when you buy it. It differs from old school nitro-cellulose lacquer in that it is a reactive finish, meaning that the molecules chemically bond together where in nitrocellulose lacquer, the finish only dries and the lacquer molecules merely "lay on top" of each other. For kitchens, it is important that nitrocellulose lacquer NOT be used since it is not nearly as durable. Shellac would not be a good choice since it cures like the nitrocellulose lacquer.

Like oil finishes, the lacquer will yellow with time. Even waterborne polys will yellow with time, some seem to almost as much as lacquer, some seem to yellow more slowly. The pre-cat lacquer is a spray only thing though. You can spray it with airless or HVLP. Most use airless around here.

I would try to use something a little more more high end than Minwax, try old masters or last-n-last poly if you want to go the oil poly route. Benjamin Moore and SW would also have some options.

**Teetorbilt** · 02-07-2008, 06:56 PM

I'm sticking with my oils, yacht quality.