What’s the best way to whitewash pine walls?
First of all, we suspect you don’t actually want to whitewash walls; whitewash is a cheap, old-fashioned paint made from slaked lime or chalk, usually used on exteriors and no longer popular with today’s Tom Sawyers. You likely want a “pickling” effect, where you use a semi-transparent white coat that allows the grain of the wood to show through. Good call: If it’s done properly, it can look very nice. And pickling stain not only looks classy, it may also help prevent light exposure from giving pine that yellowy-orange tinge over time.
You can buy a pre-made water- or oil-based pickling stain (some labels will actually say “pickling”) or mix up a batch of your own. The premixed stain is more convenient, but when you make your own, you can control how opaque the colour is by adjusting how much water you add (or paint thinner, if you use an oil-based paint). Buy a high-quality, 100 per cent acrylic interior paint and dilute it with water, starting with one part water to six parts paint. In either case, brush on the paint, let it sit briefly—about a minute for water-based paint—then wipe off the excess with a rag. Allow it to dry. How many coats you use is up to you and how much you want the pine to show through.
Before you paint, make sure the walls are dry and clean. If your wood has knots, you may get knot bleed caused by resin seeping from the knots. To prevent this, shellac and sand the knots before using pickling stain.