Woodworker's Journal 2011-35-Winter, страница 46
Walnut Oil-based polyurethane (front) adds an amber color and chatoyance; water-based polys (back) are clear. water-based does not work well as a wipe-on. You can brush or spray both types of polyurethanes, but each works best with a different applicator, method and spray technique. Here are some guidelines to get you started. Wipe-on: Use either gel or liquid oil-based polyurethane straight from the can without thinning it. Dip a fine nylon abrasive pad into the polyurethane and scrub it onto the surface of the wood. Wipe off all the excess before it dries. Apply one coat per day. Three coats will afford adequate protection, but you can add more for a deeper looking finish. Brush/pairit pad: Use a natural bristle brush with oil-based polyurethane, and thin each coat about 10 or 15 percent with mineral spirits. Thinning will help you get a smooth, bubble-free finish. Water-based coatings require synthetic bristle brushes, since natural bristles will splay and go limp in water. I find that on flat surfaces, however, a paint pad works better. It coats faster, creates fewer air bubbles in the finish and allows you to apply thinner coats, which makes water-based coatings level better. Apply a minimum three thin coats of either type of polyurethane. Spraying: Thin oil-based polyurethane 50 percent with acetone, not mineral spirits. Spray an extremely light mist coat onto the wood, let it dry for about 10 minutes, then spray a very light wet coat. The fast-drying acetone will cause the mist coat to get tacky. This tacky coat will help the thin wet coat hang without running or dripping. Spray unreduced water-based polyurethane through a small fluid tip (.040" to .050"), applying very light coats. The surface will look as if it is not wet enough and has a slight orange peel texture, but resist the impulse to spray heavier. Leave it overnight and it will level out. Spraying too heavily will result in a rough texture as well as drips and runs on vertical surfaces. Spray at least three or four thin coats of either type. A ___y Readers' Favorites: Now on CD! ROUTER BASICS! Everything from the basics to advanced techniques. 11 projects, plus tips, tricks and tool reviews. BONUS: You'll get "Your Workshop," a special issue featuring 50 secrets from our readers' shops. Item #29200 ........$11.99 W00DTURNING! 30 articles, including tools for beginners, picking the right lathe, sharpening basics and 14 great projects. BONUS: "20 Great Turning Tricks" and "11 Chucks for Your Lathe"! Item #23786 ........$12.99 CLASSIC PROJECTS! 33 projects that will help you take your woodworking to the next level. Classic designs from the Arts & Crafts style plus Green Bros., Chippendale, Shaker and more — all on one CD! Item #25838 ........$14.99 HOME PROJECTS! 30 home projects all on one CD — it's like getting a year's worth of projects to enhance and add value to your home. PLUS, over 100 useful ideas for your shop, great tips, tricks and much more! Item #23828 ... $12.99 WORKSHOP PROJECTS! 35 shop projects and over 100 tricks, tips and useful ideas for your shop! A classic, packed with great ideas for the shopl Item #32398 ........$14.99 r^yvy,. Buy all 5 CDS for 25% off! Only $49.95 (Item #25705) CALL 800-279-4441 and mention code WF011 ... ... or visit us online at woodworkersjournal.com/CDs 46 polyurethane: oll-based or waterborne |
