Popular Woodworking 2000-01 № 112, страница 12
Flexner on Finishing Continued from page 22 nificant differences (water-based varnish vs. water-based lacquer, for example) when there aren't. The names are chosen for the market being targeted. All water-based products should be labeled as "water-based," "waterborne," "aqua," or some other obvious water-indicating name so you don't have to read the fine print to determine what the product is. Other significant problems common to all water-based products are grain raising, fast drying, and poor bonding over oil-based products. Let's take each in turn. Grain Raising Despite some manufacturers' claims to the contrary, all water-based products raise the grain of wood. How could it be otherwise? They contain a lot of water. There are two ways to reduce the grain raising of a stain or finish. The first is to pre-wet the wood with water, let the wood dry for several hours or overnight, then sand it with fine grit sandpaper just enough to make it feel smooth. Don't sand any deeper than necessary or you may cut into new wood that will raise again when you apply the stain or finish. In practice you can't eliminate grain raising totally because you can't sand evenly enough, but you can reduce it significantly. The second is to reduce the depth the stain or finish penetrates. There are several ways to do this. Use a thicker stain or finish, one that has been slightly gelled; dry the wood very quickly with heat lamps and air movement; or spray the stain or finish in a light mist coat, so it flashes dry quickly. These won't eliminate grain raising totally, and each is less effective when the humidity is high. Without a way to totally eliminate grain raising, you have to deal with it. If you aren't staining the wood, the easiest way is to simply sand off the raised grain after the first coat of finish — the same procedure you use with other finishes. Try to apply enough finish so you don't sand through, but sanding through seldom caus- es a problem as long as there isn't any stain. If you are staining the wood, you can bury the grain raising. Apply enough finish so you're sure not to sand through, then sand the surface level and apply another coat or two. To learn how much sanding it takes to sand through, practice on scrap wood by sanding through intentionally. Fast Drying Fast drying is an advantage when applying a finish because it reduces dust nibs, Continued on page 26 Enter Popular Woodworking's $33,000.00 FORD PICKUP & POWER TOOL PARADISE GIYMWAY! * PLUS...Subscribe Today for BIG Savings on America's BEST Project Magazine! *No purchase necessary. To enter without subscribing to Popular Woodworking, see Official Rules below. Just imagine... Filling your mailbox with issue after issue of shop-tested, "more-bang-for-your-buck" projects... your workshop with a FULL arsenal of brand-new, world class, power equipment... and your driveway with a new Ford F-150 XLT Pickup! Imagine no more! Because now that dream can be yours with Popular Woodworking's $33,000.00 Ford Pickup & Power Tool Paradise Giveaway! Subscribe today, and you'll automatically be entered to win this $33,000.00 prize bonanza. Just fill in the attached postage-paid card and mail it today! JUST A FEW OF THE GREAT TOOLS YOU CAN WIN! POPULAR WOODWORKING'S $,'{,'{,000.00 FORI) PICKUP & POWER TOOL PARADISE SWEEPSTAKES OFFICIAL RULES 1. No purchase necessary. Void where prohibited. 2. To enter, follow the directions published. All entries must be received by the specified date published on attached card to be eligible. Sweepstakes ends September 29, 2000. Entries with orders for Popular Woodworking must be on original forms (no reproductions). No responsibility is assumed for lost, late, misdirected or nondelivered mail. 3. To enter without ordering Popular Woodworking, DO NOT USE THE ADJACENT CARD. Print your name and address on a 3"x5" postcard and mail to POPULAR WOODWORKING'S $33,000 Ford Pickup and Power Tool Paradise Giveaway, P.O. Box 5460, Harlan, IA 51593-4960. 4. The grand prize winner will be selected on or about October 30, 2000 in a random drawing from all eligible entries received. 5. Giveaway open only to residents of the 50 United States and the District of Columbia who are 18 years of age or older. Employees of F&W Publications and Marden-Kane, Inc. and their immediate families are not eligible. 6. For complete sweepstakes rules, send a stamped, self-addressed envelope to POPULAR WOODWORKING'S SWEEPSTAKES GIVEAWAY RULES, ATTN: MF, 1507 Dana Avenue, Cincinnati, OH 45207. Residents of VT and WA omit return postage. 22 Popular Woodworking January 2000 |
