Woodworkers Journal 259 Q&A

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Is Cove-cutting on a Table Saw Safe?

I want to build coved, raised panel doors, but I do not have the equipment. I have seen several articles on the Internet where the table saw blade mills a cove on the panel's edges. This entails perpendicular movement of the panel blank across the table saw blade. I see this as a safety hazard without a blade guard, but what about the blade itself? Is it safe to use a table saw blade in this application, and can damage occur to the blade? - Don Horton

Tim Inman: This is a procedure for very highly skilled, very highly accomplished and experienced woodworkers. It can be done safely, but it is also a dangerous operation if not done correctly. Passing wood at an angle more or less “perpendicular” to the saw blade can indeed cut coves. The cut is NOT done all at once. Rather, the cove is cut by making multiple, progressively deeper passes. The exact angle determines the parabolic arch of the cove. A circular cove would indeed be passed at 90 degrees. An elliptical cove (more common) would be passed at some other angle. This operation requires shop-made auxiliary fences.

I do not recommend you attempt to make your panel door edges with this technique. If you have a number of panels to make, consider purchasing the correct tooling, or finding a friend that can help you. If you have only one or two, why not carve the coves? This isn't as difficult as you might imagine. A very sharp carving chisel or two, and some time, and you'll have your coved panels - and all your fingers left!

Chris Marshall: Don, as Tim points out, cutting coves on a table saw is definitely doable. Dialing in the correct angle of approach on the blade is what establishes the precise curvature of the cove, and that takes some mathematics or trial-and-error to get right. It's actually a pretty cool technique, and one I used to create a large picture frame in our December 2009 print issue. Take Tim's advice to heart: this is a technique that requires very shallow passes and a sturdy fence setup to execute safely, but it definitely can be done. Find a woodworking book that covers the setup process step by step, and follow it. Use a full-kerf blade for maximum stiffness. You won't bend the blade or turn your workpiece into a missile if you keep each pass limited to about 1/16 inch of material removal (or less) at a pass. Certainly, this is one of those techniques that doesn't lend itself to most typical guard styles. Use push pads and push sticks to keep your hands safely clear of the blade. Keep the wood pressed firmly down against the table at all times.


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Repairing Chair Leg Joints

I have a kitchen chair with loose legs. How do I fix them? - Kenneth Belcher

Tim Inman: The very best way to repair those loose legs is to completely disassemble the chair, clean the joints, and reglue it. There are alternatives, but they have shortcomings. I'll review two alternatives. First, If the joints are not too loose, or filled with layers and layers of paint, one possible alternative is to flood the joint (very carefully!) with cyanoacrylate glue. (Super Glue is one common brand name.) I prefer a CA that is “alcohol” thinned for this, because it will find its way deep into the joint through capillary action It will take care, patience and skill -- and more than one application. It works well. (WARNING: Somewhere on the label will be the words, "Bonds Skin Instantly." They ain't kiddin'.... Be very careful.)

Another alternative is to drill a tiny hole into the bottom of the joint, and inject an adhesive using a syringe. This, too, can be effective, depending upon the joint condition, the cleanliness of the joint and the kind of glue used. It can be difficult to force the glue throughout the joint. With both these methods, the joint is never cleaned. This ultimately spells trouble.

Better, though, is suggestion Number One. Take the chair apart, and do it right the first time. Clean the old glue away, fix any broken wood, and enjoy a long-lasting repair job. One little trick I can offer is to put two small pieces of removable masking tape at each joint. Number them "1" "1", "2" "2" and so on. This helps get the exact part back in the exact location when you are ready to apply new glue and reassemble. Just match up the numbered pieces and joints - and it all comes back together like magic.

Another secret weapon I use for regluing chairs is “shrink wrap.” I think you'll find a four-inch roll available at building stores, etc. It is common. Use it to replace clamps. It works like giant rubber bands or tourniquets. Shrink wrap banding makes bar clamps pretty much obsolete for chair gluing. It is better, faster, and easier. Make multiple “turns” until you have the pressure needed. Every “lap” adds more compression force. Be sure to set the chair on a flat surface to dry. Put a weight on the seat to hold all four legs down evenly.



Chris Marshall: With all of the forces a chair must resist (tension, compression, racking) as we drag them around, plus the weight of holding people, I'm skeptical about the strength of glue joints. Sooner or later, that glue will probably fail if the chairs get hard use. You might consider pinning the tenons in their sockets with a dowel driven into the chair legs perpendicular to the tenons. At least the dowel would provide a mechanical connection to reinforce the glue joint. If the glue does give way eventually, the cross dowels will still hold the joint together. But, you'll see the dowel ends with this approach...that's the price you pay for added insurance.



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Resolving a Rickety Bed Frame

I am a member of the Society for Creative Anachronisms (SCA), and we do a lot of camping. Because neither my wife nor I can sleep on the ground without waking up in a lot of pain, I built a queen-sized bed using glued together 2x4s as corner posts (since the only 4x4s that I could find that weren’t pressure treated turned out to be rotten), side rails made out of 2x10s, head- and footboards made from 2x12s (two boards, one on top of the other to make a tall headboard), four slats topped with three-quarter-inch plywood underneath a queen-sized futon mattress. The 2x0s, the 12x12s and the 2x4s I used to make the corner posts are all of white pine.


In order to make this bed easy to take apart for transport, I used hardware that is similar to that used on beds used in the house (fingers that fit into sockets). Unfortunately, the bed was very hard to set up: it fell apart on my son several times as he tried to set it up. To try and fix this, I replaced this hardware with hinges so that I could pop the pins out when I wanted to take the bed apart. However, the bed is not as stable as I would like. Can you give me any suggestions on what I can do to make this bed more stable? We will be using the bed the end of this month on a camping trip, but I am planning on rebuilding it from the ground up this fall/winter.

Since the bed is used for outdoor camping I was also thinking of using pressure treated 4x4s for the corner posts. - John Bridges



Chris Marshall: It sounds like the hinge hardware still allows too much play when the pins are installed to keep the framework tight and stable. I would want a better solution as well. You've also tried the bed rail fasteners, but with disappointing results. I have two ideas — both for you to consider when/if the time comes to rebuild that bed. First, consider using bed bolts run through the corner posts and threading into captured nuts in the rails. Tightening up this hardware should take the "slop" out of the bed frame and still give you the knockdown convenience you want for transport. You can see a photo of those bolts here. Rockler sells them, as do other woodworking suppliers. Another option would be to connect the rails to the corner posts with long through tenons, then use a wedge tusk to lock the tenons against the back sides of the posts (think of a traditional trestle table base). This would also give you a way to disassemble the frame, but building the frame would require more sophisticated woodworking at the outset.


Tim Inman: All that lumber is overkill, John. But, if that's what you want, then you have to deal with the consequences. There is no way in my mind that much lumber can be made lighter and easier to handle. Short of building the bed on a trailer, permanently, I'm at a loss. If it is just comfort you're after, why not use a nice inflatable mattress that folds up when you're done with it?