Sealcoat instead of primer

[joe milana]

I'm finishing some cabinets with General finishes pigmented poly, and was considering priming with Zinsser sealcoat instead of the WB primer available from General Finishes, mostly because I have the sealcoat on hand, and also to avoid the grain raise I get with the WB primer. Anyone see a problem with this?
Also, I've never sprayed (HVLP) the sealcoat before. Any general guidlines for spraying? The can says don't thin. Suggestions? Thanks!

[Scott Holmes]

Biggest problem I see is the pigment added to the finish. Technically this make it a "toner" and toners should always be applied between clear coats; so, yes use the seal coat.

Now for the gotcha...

You didn't say what you are finishing nor did you spec the wood type.

Toners are difficult to apply evenly over large areas UNLESS they dry VERY fast. Poly is snail pace slow compared to the fast I'm talking about. Most toners are shellac or lacquer based, they dry-to-the-touch in 10 minutes or less. Your poly will take an hour or more... here in lies the problem... the slow drying poly will have time to pool, puddle, drip, sag and run. Since the pigment color is in the poly the color will emphasis the pool, puddle, drip, sag or run. This is especially true in pigmented toners, I like dye based toners MUCH better.

[joe milana]

Sorry for the lack of clarity. The general finishes pigmented poly is water based & will be white.

[joe milana]

A response from Jeff at Homestead read: "You can use it, but a better product would be Zinsser BIN primer". The response came with no explanation, but I'm assuming the BIN has more hiding ability, and is a more durable product.

[Prashun Patel]

Joe-
Zinsser BIN is pigmented. It contains shellac too. You will likely require fewer coats of top coat if you use a pigmented primer.

Also, it's a misconception (IMHO) that only waterbased sealers will require light sanding before topcoating. In my experience, the first coat of ANY type of oil based or waterbased finish goes on slightly rough and benefits from *light* sanding - even your Zinsser BIN.

[Scott Holmes]

Joe,

Zinsser BIN is shellac based primer; it dries FAST.

Are you going for a whitewash look? If so the product you chose will work fine... spraying is the best way to get even coverage. I don't think a primer is needed in this application.

[joe milana]

Joe-
Zinsser BIN is pigmented. It contains shellac too. You will likely require fewer coats of top coat if you use a pigmented primer.

Also, it's a misconception (IMHO) that only waterbased sealers will require light sanding before topcoating. In my experience, the first coat of ANY type of oil based or waterbased finish goes on slightly rough and benefits from *light* sanding - even your Zinsser BIN.

Prashun, my original idea was to use something besides a WB primer to avoid the grain raise I have been getting with the product I was using (General finishes Enduro undercoater). The product is "high build, and powder sands really nice, but I was having problems with dry spray. After suggestion that I keep thinning, it was so thin that I wasn't getting coverage, and hence the grain raise even after multiple coats. Also, when spraying large plywood panels, I was getting warping. I'm hoping the shellac based product will eliminate this I tried several "off the shelf" primers (BM, SW, etc), but they just don't sand like the Enduro does.

[Jerry Thompson]

What does the "BIN" acronym mean?

[Hugh MacDonald]

I can't comment on the feasibility of using the SealCoat in lieu of a primer, but I am right in the middle of spraying SealCoat with my HVLP turbine rig very, using it as a sealer before spraying Target's Super-Clear Poly product on maple kitchen cabinets I'm making. I am very new to spraying--this project is my first attempt at spray finishing--and have found the SealCoat to spray extremely well. I can't believe the SealCoat can says not to thin, as shellac has been known through the ages for its flexibility and simplicity in thinning to achieve the lb. cut you desire. I believe the SealCoat comes as a 2 lb. cut out of the can, and you can use it as such, but many recommend reducing it to a 1-1.5 lb. cut. I have always done so with great results. I used that cut for rubbing and have maintained it once I began spraying.

From my very limited experience, it has been somewhat easier to spray the shellac than the Target WB poly. BTW, I'm surprised that General recommends thinning their WB product, as thinning WB finishes is usually discouraged by the manufacturers and spraying experts. From what I've gathered, you want to thin WB finishes 10-15% at the most, and then only if you really have to. In any case, the SealCoat seems to go on beautifully, with minimal grain raising. I'm using it to give the maple a little more pop and richness, before I spray the poly for more durability and protection in a kitchen setting. As I am a spraying beginner, the ease of spraying shellac and the quality of the finish was enough to give me some confidence in my spraying ability, especially in approaching the WB poly. It's hard to describe, but even though you're putting it on with a gun the shellac almost seems to feel different while spraying it. Maybe I'm making this up, but like I said, the shellac seems to feel better coming out of the gun. One thing to keep an eye on when spraying shellac is the temperature and humidity, as shellac, because of its relatively fast drying profile, can blush in high temp/humidity conditions, in which case it's good to have a retarder on hand to make the shellac dry more slowly. I haven't had to use it, but have heard that it can make a beneficial difference.

[Rich Engelhardt]

What does the "BIN" acronym mean?

3 purpose Bulls-I-Namel.