Tabletop Fasteners Solid connectors that allow movement By Paul Christian Figure 1: Attaching Fasteners Many woodworkers have learned the hard way not to glue or screw a solid wood tabletop to its base. This can be a painful lesson in wood movement Seat Z-clips and buttons Approx. 2" fully into end aprons because a secured tabletop that shrinks during the dry season Side apron Set back spacing from side can crack in response. On the approx. 20" apron to other hand, expansion during allow wood the humid months can cause the expansion Wood moves joint to blow apart at the apron. across the grain The solution is to use fasteners designed for the job. The three most common forms are

"Z-clips" and shop-made wooden "buttons."store-bought They're "figure-8" all easy and to Side Apron End apron Angle figure install and allow the wood to 8 fasteners expand and contract seasonally. on side apron Keep in mind that wood moves only across the grain, so mount the fasteners appropriately, as shown in Figure 1.

24 woodcraftmagazine.com Aug/Sept 2010 Photo B). After assembling the table base, orient theflathead side apron screw fasteners ( at an angle before screwing them to the underside of the tabletop. Z-clip fasteners Z-clips are strong and offer a good choice for all sorts of tables (although they're not very attractive). One end is screwed to the tabletop, while the other A sits freely in a slot cut into the B a recess in the apron to apron. To locate the apron slot, Screw the fastener to the apron accommodate the exact thickness measure the offset of the clip after chiseling the edges of 1 of the figure-8 fastener. (Photo C), and then add 32", the recess to allow pivoting. which will ensure that the⁄ clip Figure-8 fasteners pulls the top tightly to the apron. The apron can be slotted How Much Movement? screw to both the apron and the various ways. One approach is to When calculating seasonal tabletop,Figure-8, andor "desktop," can pivot fastenersslightly cut a 1 "-wide × 3 "-deep movement of a tabletop, figure 3 to allow a some wood movement. on the⁄ 8tablesaw before⁄8 attaching roughly ⁄16" per foot of board These work well for smaller the table legs. Alternatively, cut width. This determines how tables but, due to their limited the slots after assembly with deep to place the fasteners in swing, I wouldn't use them for a biscuit set for a #20 their side-apron grooves. For example, if you're attaching To allow tabletop-to-apron with a 3 "-deep slot-cutting a 24"-wide tabletop during tops wider than about 18". biscuit or with a outfitted contact, drill a recess for each bit and ⁄bearing8 (Photo D). the most humid time of fastener in the top edge of the When attaching the tabletop, the year, seat side-apron aprons on the drill press before position the clips far enough clips fully in their grooves. attaching the legs (Photo A). from the side aprons to allow the In the driest season, set 3 Position the screw location about appropriate amount of cross-grain them back ⁄16" to allow for 3 16" in from the inside edge of wood movement. The end-apron future expansion. For wide the⁄ apron. the edges of the clips should be seated fully in tabletops, use large buttons recess to allow for swing, and their slots. Attach the clips with with longer tongues that slip then install the fastener with a panhead screws long enough to into deeper apron grooves. provide good bite into the wood.

C Determine the necessary offset D 1 of the apron slot by measuring A ⁄8" slot cutter can rout clip grooves after the table base is 1 the clip offset and adding ⁄32". assembled. a board to the apron to prevent router tip.

Photos: Paul Christian Aug/Sept 2010 woodcraftmagazine.com 25 Wooden buttons Figure 2: Button Attachment Wooden buttons are used to attach tabletops on much high- 1" Table top end furniture. They're very strong and exude an aura of 1 ⁄2" make a bunch at one time and savefine craftsmanship. some for use on You future can projects. Install them in the 3 ⁄4" same manner as Z-clips. Gap allows 3 table top ⁄8" To make buttons on a tablesaw, movement 3 4 3 ⁄8" Wood #8 panhead × 1 × 24" long for safe handling.⁄ Setfirst up mill a a strip head of hardwoodfor a 5 "- Apron button screw ⁄8 with an auxiliary thatwide reaches cut, and to outfit the blade. your miterPlace a thick stopblock against the fence 1" to the side of the blade. Then clamp the stopblock to the fence a few inches in front of the blade and lock the fence. Register the strip against the miter gauge and stopblock, to a dado on each end. Use a spacer to reposition the fence 1 5 " further from the blade (Photo E⁄8), and then cut the next dado on each end. Reposition the fence and repeat the process to dado the rest of the strip (Photo F). Bore a series of clearance E F 5 holes for the screws. (Photo G) Cut a dado in each end of the button stock and then use a 1 ⁄8" Saw each button from the strip spacer to reset the fence and stopblock for the next cut on each by aligning the the saw teeth end (left). Continue in this manner to dado all the buttons (right). with the rear of the adjacent button (Photo H). (For safety, stop the saw before moving each offcut button away from the blade.) Finish up by sanding decorative on the rear ends and sides of the buttons, as shown in the lead photo. Safety Alert When crosscutting with a miter gauge, never use the rip fence itself as a stop, as pinching a H crosscut workpiece between the G Saw the individual buttons from blade and fence invites kickback. Drill the screw clearance holes the stock using a miter gauge that in the dadoed button stock. extends all the way to the blade.

26 woodcraftmagazine.com Aug/Sept 2010