A Simple guide to Finishing Wood
My father always told me that a good foundation was the most important part of a job well done. That holds true for so many things, including properly finishing your latest wood project. Here are some steps you can follow to achieve a professional looking finish.
1. Sand paper, both med(100 to 120 grit) and fine (150 to 220 grits) , nylon sanding pads, sanding sponges for curved or concave surfaces)
2. Belt and orbital sanders ( if you own them)
3. Pure china bristle brush
4. Clean, lint free cotton cloths
5. Paint thinner
6. Steel wool (0000)
8. Varnish or polyurethane
9. Tack cloth
10. Cabinet maker's wax
11. Artist's brush 12. Stir sticks
Preparing Your Work:
1. Begin by sanding with medium grit sand paper, always sand with the grain. In some extreme cases, such as uneven glue joints, I have found it useful and time saving to cross sand ( sanding at right angles to the grain). I'd suggest some practice doing this before attempting it on a good piece of work. After cross sanding, return to sanding with the grain taking care to remove all cross sanding marks.
2. After rough sanding is complete, start finish sanding. Again, with the grain making sure all cross sanding marks are removed. Check your work by holding it in different light and different angles. I find my hands feel more than my eyes see, so I use touch to find mistakes and defects. Run your hands over your work slowly and feel the surfaces. Check all your corners for glue seepage, if you find any, a sharp carving chisel works to remove it, or even old dental instruments work very nicely.
3. At times during finish sanding you will encounter spots that are very difficult to get smooth, or a glue joint that still shows unevenness. Here's a trick that works well. Using a glass cutter, cut squares of regular window glass in 2" squares. Take a piece of glass in your fingers and scrape the surface of the wood, holding the glass at approx. 45 degrees as you pull it across the wood. When the edge gets dull turn it over, you have eight cutting edges on every piece. You will be amazed at how smooth and clean the glass will cut. Glass also works well removing old finish from antiques.
Use of Fillers:
If you have areas that require filling and are using a filler that will accept a stain you will apply it after rough sanding and blend it with finish sanding. I have found that, although the manufacturers say they accept stain, fillers don't stain very well. I prefer to mix the dust from sanding with glue, making my own filler, which matches much better.
Paste wood fillers are used on porous wood such as red oak to fill the grain and should not affect the color or your finish.
Putty sticks are commonly used to fill small holes. You can match them closely to your stain. I recommend waiting until your first coat of varnish is dry to apply putty stick filler to holes. This way you eliminate the chance of rubbing or smudging the filler in surrounding grain. Fill the hole and use a cloth, damp with thinner, to remove the excess around the hole, taking care not to rub to hard and leave a depression over the hole.
Get Ready to Finish:
Try to create as dust free of an environment as you can. Work in a ventilated area, not only for your own safety, but it also aids in drying of the finish.
Whether you are using poly or varnish, it is very important to not shake the cans . This creates bubbles which are carried to your work and leave a rough finish. If using a gloss varnish, open the can and start using it, do not stir or shake it.
Satin, or semi-gloss varnishes should be stirred gently with a turning lifting motion to thoroughly mix the product. Again, Do Not Shake the can.
Regardless of the final look you are trying to achieve, start with a first coat of high gloss. It is clear, dries faster (minimizing dust collection on the surface), penetrates deeper and sands easier. Successive coats of satin may follow.
Remove your brush from the thinner and shake it once or twice to remove excess thinner. It is not necessary to wipe the brush dry . The remaining thinner in the bristles will replace that which evaporates from the varnish while open. Often, when doing a large project I find my brush starts to stick as I am working. At this point I emerse it again in the thinner , shake it out and go back to work. This will make the brush work more easily. You will find that not all varnishes and polyurethane's work the same. Some are harder to spread than others and this often requires some for of thinning. As long as you are using a solvent based product , I recommend using a product called Penetrol (made by the Flood Co.) If ever there was a cure all product in the paint industry , this one comes very close.
Begin the second coat using the same method of application as you used on the first, followed by another sanding , wiping and application of a third and final coat. Allow to dry for at least 8 hours.
At this point you should have a relatively smooth , attractive looking finish. To add a finishing touch use the 0000 steel wool dipped sparingly into a can of cabinetmakers wax (I have used Goddard's Cabinetmaker's Wax for years ) . Apply the wax with even stokes with the grain of the wood. The steel wool will remove small imperfections left in the finish by dust particles and will also embed the wax into your finish. Be careful not to rub too hard , especially near the edges. The wax will also prevent the steel wool from cutting too much into the finish. After several minutes , using a clean , dry cloth, buff the surface of your finish.