What type of primer is required for pine

Ammonia:

"…the objective is to remove the shellac from the brush, roller, etc, not to thin the shellac that is still in the brush.

Now, the explanation; just as mineral spirits/paint thinner won’t completely remove varnish from a brush, neither will alcohol alone completely remove shellac from a brush. Alcohol will dilute the cut of shellac but there will still be some shellac still in the brush. Ammonia breaks down the shellac so that washing the brush with mild detergent and warm water, after a soak in ammonia, will completely remove all traces of the shellac. When we clean a varnish brush with paint thinner we are only thinning the varnish; some of the varnish remains to cure in the brush. But, when we wash the brush in warm water and detergent (after cleaning in MS/paint thinner) the soap “grabs” the remaining molecules of varnish so that all of the varnish is rinsed from the brush…"

I was quite skeptical about the paint and primer combo's, but Valspar gave me a couple of gals to try out. I was surprised how well it covered over dark colors. The down side was that it is not as smooth as regular premium grade paints. It seemed a bit dry going on, but that is because it is very high in clay content. I decided the best combo was to use it for the first coat and then use regular paint treated with Flowtrol for my finish coat. The application that I would never use it on is covering new drywall. I still prefer quick drying PVA drywall sealer. The paint/primer combo is too heavy and stays wet too long for new drywall, and is about twice the price of PVA primer.