"Phisherman" wrote in message
...
On Wed, 24 Oct 2007 13:22:01 GMT, "efgh" wrote:

I've been using shellac to seal pine knots and I've been happy with the
results in that the knot doesn't bleed through. The problem I have is
that
I usually end up painting the project with white paint which doesn't cover
the shellaced spots very well. I have to put on at three coats of paint
to
cover it and even then, it still doesn't look very good. Before anyone
suggests I switch to a different type of wood, I use pine because it's
cheap
and I don't mind covering it with paint. I'm not a big fan of using a
hardwood to just cover it up with paint.

Does anyone else use something besides shellac to seal the knots that
works
well when painted? I know Zinser makes a primer that includes shellac and
I've used it before but after a year or so, the knots still bleed through.

My method once sanding is complete is to put the shellac on the knots,
sand
lightly with 220 grit, then apply latex primer, sand again lightly with
220
grit, then apply latex paint.

Thanks in advance.



Coat the knots and any resin veins 3 or 4 times. I put up some
painted crown molding (on a 18-foot ceiling) that I had primed with a
shellac-based primer. It looked great, but after 3 years I started
seeing resin patterns emerging. I sanded these areas, shellacked them
4 times, then painted over. It has been 10 years without any
bleeding. Some of the (pine) door trim did the same thing. White
shades of paint are the worst.

One coat of shellac works well for me. The problem I have is that it
usually takes 3-4 coats of white paint to cover the darkness of the shellac
so you can't see it. I'd like to use something lighter in colour like a
polyurethane but I'm wondering if has the same sealing results of shellac.