Popular Woodworking 2007-04 № 161, страница 55

the dowel won't penetrate as deep as you expected and the joint may not pull fully together.

To add grooves to a maple rod of the proper dimension, scrape with the 90° corner of a chisel or make a jig to add them. Drill a hole slightly larger than the diameter of the dowel (I use metric bits) through a small block of wood and insert a screw from the side so it protrudes about ¹/32" into the hole. Then drive the ungrooved dowels through the hole several times each so several grooves are scraped into them by the screw.

In all cases, the dowels should be chamfered on the ends so they line up quickly in the holes as you are inserting them. You can chamfer cut dowels using a rasp, chisel, large pencil sharpener or sandpaper, ideally attached to some type of sanding machine.

It's usually best to insert new dowels into the rails first. In other words, into the parallel part before the perpendicular. It won't matter if the dowel tap s out at the bottom of the parallel hole, but you want to leave at least V32" at the bottom of the perpendicular hole to allow for cross-grain shrinkage. If you don't, the leg might split.

You may need to trim dowels to the proper length before inserting them into the legs.

All surfaces should be coated with glue. This means the sides of both the holes and the dowels. It's easiest to do this with a narrow brush, working out of a glass or plastic container.

When clamping the chair back and chair front, it's important that the parts be square. You can check this by measuring the diagonals - that is, from the top of one leg to the bottom of the other. The two diagonals should be the same. If they aren't, adjust your clamps at angles to make them so. Look at the photo on the first page of this article to see an example. I'm

lowering the front leg by raising the clamp on it and lowering the clamp on the back leg. I've done the opposite on the far side. I have exaggerated the angles so you can see them better.

When clamping the front to the back, it's important that all four legs touch a flat surface so the chair doesn't rock. With the clamps on the chair, place it on a flat surface such as a table, floor or table saw. Adjust the clamps if necessary by raising and lowering opposite sides until the chair doesn't rock. PW

From the left are a spiral-grooved dowel, a straight-grooved dowel, a dowel pin cut from a maple dowel rod and a smooth surface maple dowel rod. Spiral-grooved dowels are the best because they provide plenty of glue surface together with grooves that allow excess glue to escape from the hole. Straight-grooved dowels are weak because they don't provide enough glue surface. To groove dowel pins cut from a dowel rod, drive the pins through a hole drilled in a hardwood block with a screw inserted so it protrudes about V32" into the hole. Be aware that machined dowels and holes often differ slightly in dimension so you may need to make some adjustments.

Hide glue is easy to clean from joints. Simply wash or scrub it off with hot water. For hot water in my shop, I use a commercial coffee maker I bought used at a yard sale. To clean white or yellow glue, you may need to scrub using hot water and a stainless-steel scrubbing pad from the supermarket. For adhesives that don't soften in water, you will need to scrape or rasp them off the wood.

Apply glue to both the dowels and the holes before putting them together. The only way to do this efficiently is with a brush.

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