Tuesday, June 22, 2010

Refinishing for fun and profit, Part 2

The penetrating resin finish is a synthetic form of boiled linseed oil, which is still available in hardware stores and can be used as well. Linseed oil takes a little longer to dry, and doesn't dry as hard as Minwax, but many folk use it instead. Minwax comes in clear (natural the can will say) and with various colors, (stains). Old furniture usually has a lot of wood color, for which natural Minwax is appropriate. If the piece is lighter than you like, a stain can darken it. Stains won't lighten anything. A piece that shows a solid dark walnut color will remain solid dark walnut even after a coat of Minwax colonial pine.
Many pieces look very good done in penetrating resin. However there is some formal furniture that calls for a glossy finish. The easiest to apply is shellac and wax. Shellac is the resins of an Asian insect dissolved in alcohol. It flows on easily and dries rapidly which means the dust doesn't have much time to settle in the wet shellac. Let the first coat dry overnight and then you have to sand the piece again. The shellac raises the wood grain giving a nubbly feel to the surface. A light sanding with 220 grit will make it feel glassy smooth to the touch. Wipe the sanding dust off and you can give it a second coat of shellac to cover the places where you sanded a little too hard and exposed the wood. Let the second coat dry overnight and then you can wax it. I use Butchers paste wax, but other carnauba containing paste waxes, sold for wood floors and bowling alleys will work too. Rub it on, buff it up with a clean dry rag and you are good to go.
Couple of things. Shellac has little to no resistance to alcohol or water. It is not appropriate for bartops or kitchen and bath areas. The wax is pretty good at keeping the shellac dry against water spills, but a spilled drink will dissolve both the wax and the shellac. Shellac has a relatively short shelf life. The cans are dated, and it is not unusual to find out dated cans sitting on the shelf in the hardware store. Don't stock up on shellac, it will grow stale before you get to use it. If there is a question about the freshness of a can of shellac, put some on a test scrap of wood and see if it dries hard overnight. If the test scrap is still sticky in the morning, toss the shellac.

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