I’m finishing up my adaptation of Norm’s router cabinet and have been mulling over how to finish it. I used shop-grade plywood that isn’t worth using a clear finish on. I thought I might shellac the entire cabinet in and out as a way of sealing it and then paint over the shellac on the outside of it. (I’m also using some hard maple trim, which I’ll finish with an oil/varnish blend to play off the painted plywood.)
My question is: does shellac work well as a primer under latex paint? Also, is there any advantage, either in expense or finish quality, of using shellac under paint as opposed to a conventional primer? I just figured since I’m finishing the inside with shellac anyway, why not keep going and skip the primer.
Norman
Replies
If you're going to paint over it, I'd suggest a good primer intended for latex rather than shellac. Of course, you can have both: Zinsser's B-I-N primer is shellac-based, and works very well under latex. I use it whenever I think there's a risk of bleed-through of some contaminant that's already on the surface (knots, embedded grease, etc.) However, I think Zinsser's acrylic-based 1-2-3 primer is a little easier to use (water cleanup) and probably works about as well as a sealer, although I haven't yet had much experience with it.
-Steve
I stripped many door and window casings in my house. Underneath it's softwood (130+ years) with quite a few knots. I started using regular oil based paint primers, but then moved to Zinsser B-I-N which definitely holds in the resin. Also the bin primer sands extremely flat and easily between coats so the top coats (latex high gloss enamel) come out looking beautifully smooth.Hope this helps,
Best regards,
Paul
http://www.zinsser.com/product_detail.asp?ProductID=72
I would recommend the Bulls-Eye seal coat for what you're trying to do. It's a thinned, clear, de-waxed shellac. Will look good on the inside of the cabinet and can be used as a primer for both the paint and the varnish.
I have used shellac as a primer on knotty woods like pine. Many years ago I spot primed the knots on barge boards,then painted them before installing. I noticed the finish was shinier where the knots were primed. Had to lightly scuff with sandpaper before painting the last coat. Next time I had barge boards to paint I shellaced the entire board. This gave me a finish that looked really good. I have been using shellac or now shellac base primer whenever I paint knotty woods.
mike
Absolutely. I use dewaxed shellac under to be painted surfaces. Really takes care of the bleed through from knots.
Work well? maybe, generally - Yes.
I generally use a primer 1st UNLESS I have a concern of bleed through. I've had knots start to reappear after a few years EVEN under a primer. I always cover knots, ply glues etc.with dewaxed shellac 1st. Zinzer seal coat is fine or just as simple, make your own. Then prime over shellac. Shellac is a hard sealer but it's very smoothness reduces the tooth for painting. Of course you could sand it all for "tooth" which then reopens your bleed through factor. Primers act as a binder to the shellac and offer a grabby surface to the finished paint. My experience is that shellac alone as a primer under latex may lead to long term latex adhesion failure. Just my experience.
I just do it (shellac) on trouble spots. It might be overkill to totally shellac many cabinets and then prime and then paint 2 -3 times with sanding in between. One cabinet- Ok
I hate paint.
John
Thanks, all, for the info. I think I'll shellac the inside of the cabinet to seal it and use a primer for the painted surfaces on the outside. Because this is plywood, knots aren't a problem and the exposed glues will be covered with maple edging. Besides, I think I've got a can of leftover primer around here somewhere. Now, all I have to do is find it . . . Norman
Zinzer BIN is a pigmented Shellac primer. It is the best for oil and latex paints. It covers OK but it drys very fast and sands perfectly. It can also be tinted to the top coat.
Mike
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
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