At some point, if you have an outdoor wood table or bench, you will consider refinishing your furniture. It is not uncommon for redwood, left to its own devices in the weather, to splinter and crack. In fact, this is common for most wood that is left outdoors. Even pressure treated wood will tend to do likewise. Redwood, I must admit, tends to splinter more with the aging process because of its grain.
The trouble with sanding something that has developed surface splinters can be a problem. What happens is that if you are not careful, the splinters will only become thinner and stick out farther from the board. Light sanding, to smooth the boards, is all that should be required.
If the wood has become gray in color due to weathering, you can use the following solution to clean and lighten it before sanding. To mix a gallon of this solution, use one quart of household bleach, three quarts of water and three to four tablespoons of a non-ammoniated detergent. Shake this mixture thoroughly to mix it. This solution can be used to scrub the wood. Apply it liberally with a sponge and work it into the wood (make sure to use rubber gloves if you are sensitive to bleach). The bleach will kill any fungi that might be present in the surface of the wood. It will also tend to bleach out some of the graying in the surface. The detergent helps to clean off any dirt. This also works better on a sunny day. Once the scrubbing is completed, let it stand for about 15 to 20 minutes to let the bleach act. Next, rinse the wood with clean water. Let all the pieces dry completely.
There are some acrylic finishes that can be poured onto wood that completely encase the surface in a thick, tough, clear finish. These materials are expensive and require some expertise. It is best to do the work in a dust-free area. The way they are usually applied is this, a form is made around the piece to be covered, and enough of the acrylic is mixed to fill in this form. You may have seen this type of surface finish on tables in some restaurants. The problem is that I can’t think of one of these that would give you a satin finish.
There is a more tedious method that can be employed, but it will require that you practice a fair amount of patience. If you plan on staining, you might consider using a very thin stain first. You’ll need to let it dry completely before starting the next step.
At a good hardware store or at some full service paint centers where wallpaper is sold, you can purchase a small hard roller. This type of roller is used to roll air bubbles out when applying wallpaper. You’ll need one of these. An old plastic rolling pin may do the job if you have one. Buy a thick acrylic varnish that develops a lot of tack or stickiness when drying. Remember that you want one with a satin finish. You can get some advice from a salesman at your local paint store. Buy a good natural bristle brush and the appropriate solvent for the varnish that you purchase.
Using the brush, work the liquid down into all the cracks and under all the splinters. You may even have to lift some of the splinters to get the varnish under them. Coat the entire surface evenly; you don’t want too much material in one place because the idea is to let it dry uniformly.
Here is where the stickiness and the roller come into play. Keep a close eye on the drying process and test the tackiness occasionally with your knuckles. When the varnish pulls nicely on the skin on your knuckles, it is time to go into action. Take the roller and use it to push the splinters into place. The varnish is acting like a glue to hold the splinters down. All the splinters may not stay in place using the roller. You can use some wax paper and a weight to clamp the stubborn slivers. You may have to repeat this whole process again until all the loose areas adhere.
Once everything is in place, you can sand it lightly with very fine sandpaper and apply another coat to the whole thing. You can add as many coats as you wish, repeating the light sanding with sandpaper or steel wool between coats.
By using this method, you can achieve the stain finish you want and stain the wood as you wish. Remember patience and planning are keys to a successful project.