An Open Forum For Questions And Comments

ROUTER DEBRIS

/ built the router table in Woodsmith No. 20, and was happy with the design until I ran into a problem. A chip of wood dropped down into my Sears router, and the fan blades started to break off. Then the fan blades fell down into the armature, causing the entire unit to self destruct!

Vm guessing that with the amount of wind that's generated by the fan, the wood chip may have fallen into the fan when the unit was turned off, but Vm not, sure. A word of caution would have alerted me to this possibility. I know that you can't think of everything, so please pass the word along.

Eric Jensen Oconomowoc, Wisconsin

We've heard this comment from several readers, and to be honest, we've had the same thing happen to our Sears router.

I think that part of the problem is in the fan blades of the Sears routers. I'm not sure whether it's a design problem, or just a case of using poor quality steel to make the fan blades. The reason I suspect the Sears router itself is because we haven't had any problems with either the Makita or the Porter Cable routers (which have been used more than the Sears model).

In the end, I guess it's a trade-off between having the added versatility of a router table versus the chance of debris entering the motor and causing damage.

And as you mentioned, the most likely time for debris to enter the motor is when it's not running. To help prevent this I try to take the time to clean off the top of the router table after each use. The small amount of time it takes is well spent.

DOWELS

We've received a lot of calls and letters wondering why we use mortise and tenon, splines, or other "exotic" joints instead of dowels. To some extent it's a matter of personal preference. But there are some reasons why we tend to shy away from using dowel joints.

edge-to-edge gluing. When boards are being glued edge to edge (as on the table top of the Trestle Table shown in the last issue), it's customary to use dowels to "strengthen" the joint, and to align the boards as they're glued together.

However, straight edge-to-edge gluing and clamping provides more than enough strength for this type of joint. In fact, whatever else is added, whether it be dowels or splines, usually only serves to weaken the joint.

The real purpose of dowels or splines is to align the boards to eliminate a lot of extra handplaning later on.

The problem with using dowels to align the boards is really a problem of trying to align the dowel holes in the first place. Each set of opposing holes (for the dowels) must be exactly opposite each other for the length of the boards. Doweling jigs and dowel centers are designed to help with this problem. But they never seem to be able to pull it off, especially when you're working long boards (as on a table top).

Even the slightest misalignment can create major headaches during assembly. And even if the dowels can be persuaded to fit, they'll be creating quite a bit of stress on the glue line, which can cause the boards to warp, or the glue line to fail.

Using splines, on the other hand, eliminates a lot of these problems. All you have to do is cut a slot in the boards, and slip the spline in the slot. Cutting an accurately positioned slot is relatively easy to do: just keep the face of each board against the fence of the table saw with feather boards. (You can also use a router and a slot cutter if the boards are really warped.) This positions the kerf an equal distance from the face along the entire length of the board.

Shop Note: One trick we've found that makes using splines a whole lot easier, is to make the splines out of Vh" Masonite. It not only has no grain direction (which eliminates orientating the grain across the joint line), it also fits the kerf of our carbide tipped saw blade to a tee.

Another advantage of using splines is that they "feed" themselves into the groove as the boards are pulled tight. So once the splines are stalled in the groove, it's just a matter of drawing the two boards together.

end grain to long grain. Another common application of dowels is to join two boards end grain to long grain (as on the frame for a door). Usually dowels are used in this case to speed things along, or to avoid using one of the "exotic joints", such as a mortise and tenon.

Unfortunately, dowels are almost the worse choice for this type of joint . . . for several reasons. First, the amount of the long-grain surface of the dowel that contacts long grain of the hole is miniscule. Since this long-grain to long-grain contact is where the gluing strength is, there's very little strength right from the start.

And to make matters worse, dowels have a tendency to deform to an oval shape as they first absorb moisture from the glue, and then release it. The result is that the dowel begins to break free from the sides of the hole as it takes on an oval shape. This not only further reduces the gluing strength of the joint, but it also severely reduces the physical bond between the dowel and the hole. It's usually just a matter of time before the entire joint works itself loose.

By using a mortise and tenon, the long-grain to long-grain gluing surface is (by design) quite large. Since both faces of a tenon are long grain and both surfaces (cheeks) of the mortise are also long grain, the bond between the mortise and tenon provides substantial gluing strength.

The only problem with a mortise and tenon is its reputation: it's an "exotic" joint that only a master craftsman can cut. Although this adds to the mystique, it also exaggerates the difficulty, (and skill required) to cut it. Granted, it may take a few-practice shots, but that's part of the fun.

And while I'll admit that cutting a mortise and tenon does take a little longer to complete than drilling a couple of holes for dow?els, the results more than compensate the effort. (For more information on mortise and tenon joinery, see pages 12 and 18 of this issue, and also Woodsmith issues No. 8, 13, and 18.)

ANOTHER WAY

In your article "Turn ing A Goblet" fWood-smith No. 28), why not use a boivl gouge instead of scraping? It causes less vibration, works faster, and requires less sanding.

David N. Valyou Woodcraft Supply Corporation

You're right. Using a gouge to turn a goblet is quicker, cleaner, and more satisfying than using a scraper.

In fact, we had a lengthy debate as to which method to show for that article on turning a goblet. We finally decided that those of us who are starting out on the lathe, (and for Don, wiio's a real klutz when it comes to turning), the "easiest" approach would be using a scraper.

All too often, I think people get turned off to lathe work because of the sometimes frustrating failures that accompany learning how to use a gouge. But we wrant to do a follow-up article on howT to turn goblets the "correct way," using a gouge.

Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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