Thursday, April 30, 2009

Edging Plywood the Better Way

As promised, I'm answering the question left open from the last post. If you don't use iron-on edge tape, how do you edge plywood?

There are three good answers to this question. Which method you use depends on the project.

The first method is simple solid wood edging. This is the quality finish that the edge tape is trying to imitate. In essence you are cutting a 1/4" strip and glueing it on the edge. You can vary your thickness but I have always found that 1/4" just looks the best. Unless you are going for a nice bold edge, maybe 3/4", I have found that varying too far from the 1/4" just looks odd (if you are going for a larger edge, like 3/4", you are better off using one of the tongue and groove methods outlinded below). Obviously follow good woodworking practices. Run your stock through the jointer before ripping off your strip then glue that perfect edge to the plywood. Also cut the width a little over sized so that you can take it down to perfection with a block plane. Use a good quality glue. You can clamp it down but you might be able to get away with using a good quality masking tape. Depending on where the finished piece is in your project you might even be able to get away with tacking it with your brad nailer. This method produces a good quality edge that holds and takes stain well.

The second method is ideal for times when really want to hide the joint of the edge strip. When done with care the edge joint almost disappears completely. I call it V-ing. It involves cutting your strip in a v-shape and your plywood with a v-shaped groove. If done carefully, your joint ends up precisely on the corner and disappears. Set your table saw from 20-30 degrees. If your saw has a notch or setting at 22.5 degrees use that, otherwise 25 degrees is easy to remember. In order to get the cut precisely in the middle scribe a line on a sacraficial fence (a high quality marking guage is a blessing here). Advance your blade (while spinning) so that it enters the fence just a hair below the line. Do a test run. If it looks good (a tiny flat spot is okay, far better than being off center) go ahead and run all your edging through both ways making v's. Without changing the blade's angle transfer the fence to the other side of the saw (swap your sacrifical fence over too). Now cut some test runs on some scrap. You may have to adjust the height of the saw a bit. Once the bevel meets nicely (a tiny gouge in the deep part of the ve is okay) you can cut the edges of your plywood. Finally, bring the saw back to 90 degrees and cut the edge strips off the stock. Glue them up and your seem is almost invisible at the corner of your sheet.

Finally, if you have a project that you want a large, bold edge on you can use a tongue and groove. Making a tongue and groove is simple and intuitive so I won't go through the process here. Just take your time and run test pieces to get it perfect. If your edge is on the smaller size put the groove in the plywood and the tongue on the solid wood edge for strength. If the edge is quite large you can go ahead and reverse that if you want. A third option presents itself here as well. If you have a large enough edge to take a groove you might consider grooving both and using a 1/4" plywood spline. This is by far the easiest and quickest tongue and groove setup and is plenty strong.

Between these three methods, you can achieve any look you want and have quality plywood edging. Like everything else, once you do it a few times you will find these methods simple effective.