| Woodworking FAQ: Clear Finishes |
From "Ask DIY" episode ADI-507 |
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Woodworking and refinishing expert Bruce Johnson answers some frequently asked questions about clear wood finishes. Q: My neighbor says that if I stain a piece of furniture, I don't have to finish it. Is that true? A: No, that statement is not true, and that assumption will lead to dried-out, lifeless furniture. A stain and a finish are two entirely different things. - A stain is intended to darken or color wood by adding pigments but does nothing to protect the wood. When you rub stain into wood (figure A), it will bring out the grain pattern and give the wood a more dramatic look but it will offer no protection. In fact, the final step in staining a piece of wood is to wipe off excess stain using, so the process leaves nothing behind to protect the wood surface.
- A finish is typically applied after a piece has already been stained, and will add luster as well as a protective coating to the wood. A brush is used to apply a wood finish (figure B), and the finish leaves behind a protective coating that will protect the wood from spills, scratches and from drying out.
- If you apply only a stain to wood, and no finish, the wood will eventually take on a dry, lifeless look. A finish will not only add a shine, but will help keep the wood looking good for a long time. This is why in most instances it's advisable to use a finish as well as a stain on wood furniture.
Q: We're getting ready to refinish our hardwood floors. What is the best finish to put on them? A: Of all the wood in your home, hardwood floors take the most abuse. You'll want to use a strong finish on them to protect them from spills, scratches and abrasion from walking on the floors when there is dirt or grit present on the surface. Polyurethane finishes provide the kind of hard, durable finish that wood floors require. - Polyurethane is easy to apply. However, be certain to use a natural bristle brush to apply it (figure C) rather than a foam brush. A foam brush will tend to leave tiny air bubbles in the finish.
- When applying polyurethane finish, allow the first coat to dry overnight, then sand it lightly with 220-grit sandpaper. Then apply a second coat. You may want to repeat the process. Most floors require two to three coats of polyurethane to provide adequate protection.
Q: I'm looking for a finish that's easy to apply. Do you have any suggestions? A: A versatile and easy-to-apply finish is tung oil, and it's been used for centuries to beautify and protect wood. To apply tung oil, simply pour a small amount into a shallow container (figure D) and apply it with a brush, rag or foam pad (figure E). - Apply tung oil liberally, then wipe off the excess with a clean rag. Tung oil penetrates into the pores and protects the wood from within.
- Tung oil may darken the wood but unlike a stain, tung oil hardens within the wood to offer protection.
- Tung oil provides a rich, beautiful finish but the only disadvantage of using it is that, since it is very thin, it must be applied in multiple coats to be effective. About 3 coats of tung oil are required to offer the same amount of protection as a single coat of polyurethane. The good news is that tung oil is so easy to use and dries so quickly, you can apply several coats in a day. With polyurethane, you'll generally need to wait a day between coats.
RESOURCES :
The Weekend Refinisher:
How to Make the Most of Your Furniture-A Step-by-Step Guide
Author: Bruce E. Johnson
Publisher: Ballantine Books
ISBN: 034535866X
The Wood Finisher: How to Finish Everything, From Decks to Floors to Doors
Author: Bruce Johnson
ISBN: 0345372972
Ballantine Books
How to Recognize and Refinish Antiques for Pleasure
Model: 0762701145
Author: Jacquelyn Peake
Furniture Repair & Refinishing
Model: 1580110061
Author: Brian D. Hingley
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