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ShopCam HiLites for 10/31/00
Plywood

Tuesday started on time but slow. After sweeping the floor and making a feeble attempt to put away some tools, then came crunch time. I had to look at the sheets and decide which went where. As with the lumber, this chore seemed to take forever.

Fortunately there were five of the nine sheets with matching grain. They weren't sequence matched, we didn't pay that much, but I could see immediately they would be perfect for the backs and give the wall unit a unity of appearance you couldn't get with un-matched panels.

3/4" for backs - are you crazy? Well, sometimes, but not here. At 27" wide for each shelf bay, I would have needed two extra sheets if going with another thickness. As it turned out with the 3/4" stuff, the offcuts will make valuable case parts.

During this phase I'm also sorting for straightness. Most of the panels bowed enough to make them less than perfect for some areas in the project. Two particularly straight panels were selected for the extreme left vertical, which is unbound in the front, and the shelves. The rest will be tamed with glue and screws.

One of the nice things about having your bench downwind of your tablesaw, you can use it to catch long pieces. Not a bad deal huh?

The plan is simple: rip out the larger pieces first, which in this case are the parts for the backs - then whittle down the list, large to small.

Oh yeah, tablesaw guard removed for clarity of description.

Sunlight does wacky things to many woods and walnut is no exception. When you first saw open a freshly fallen log, the color of the heartwood is a pale yellow-green. Then, almost as if by magic, it starts to turn chocolate brown.

Judging from the comparison between the plywood and the lumber, the plywood is looking a bit anemic. It was sliced inside, dried inside and then laid-up on the plywood inside. I'm hoping the sun outside the shop is high enough, this time of year, to blush the plywood's cheeks a bit, or else I might have to send it on a trip to Acapulco...;)

Ironically, what sunlight gives, it eventually takes away, as Mr. D. knows very well. As it ages, that lovely chocolate brown fades.

Originally I was going to make the upper cabinets in four sections, 27" wide. My supplier didn't have walnut-veneered MDF so I had to go with plywood. I didn't mind; plywood has some serious advantages. For one, it's a lot lighter so one large 54" wide cabinet is easy enough for me to handle.

In this photo, I'm preparing the back edges for permanent joining with biscuits.

Another advantage to plywood is the thickness of the veneer. MDF is such a uniform substrate, the manufacturers can get away with thinner veneers successfully making it through the wide-belt sander. Not the same with plywood - I think I have a whole 1/30" to play with. Piece of cake!
On the downside is the possibility of having knot-holes under the face veneer. For the most part, this batch of ply is pretty good. When I saw this, I had to go around and tap the veneer on the other pieces to see how many others were hiding. I only found one and I'm not telling where it is...;)

In this picture, the back sections are glued and clamped on the bench. A biscuit under each clamp keeps the pipe out of the glue, therefore preventing any staining.

The little bar clamps around the edge keep the panels flat on the bench, which want to curl upward from the clamps. The gap between the two bench-tops leaves the wax paper in the drawer.

While the backs are taking up the bench, I while away the hours ripping and crosscutting the rest of the parts. First I rip out the upper pieces and set them aside for now. Then I rip out the lower parts.

In this photo I'm crosscutting two lower cabinet bottoms at the same time. About my panel saw, it works pretty well, is home-made and I think it's too dangerous to discuss further. Though I'm perfectly comfortable with it, I don't intend to mention it again. Sorry.

In this project, there are a few odd pieces. Where most of the parts have nice simple edges and need only rudimentary attention, every now and then, one rears it's ugly head and says, "Look at me!".

For the bottom, top and right side, the gaps between the cabinets and the existing walls are handled by moldings of one sort or another. For the left side, where a niche is created for a Grandfather clock, the plywood must be fitted to the drywall.

With this in mind, the left verticals are ripped wide and rabbeted along the rear edge to accept the back AND have a little extra for scribing to the wall. I liked to make the rabbet with the tablesaw using the the same rip setting for the other interior parts, only lower the blade to leave a 3/16" thick flange.

This is for the first cut. The second cut is made with the panel on edge and the keeper part, the one you see, against the fence.

These same parts, one for the upper cabinet and one for the lower cabinet, are also different in how they are joined. Where the others can be biscuited and screwed, these can only be biscuited 'cause looking at assembly screws exposed on the side of a finished project, isn't exactly the quality level we're shooting for.

In this photo, I'm cutting the biscuit slots in the lower cab where it intersects the bottom. I'm using the cabinet's divider as a guide for the machine, since it's length determines the location of the bottom in elevation.

When I can't squeeze some screws into a cabinet joint, I tend to go overboard and cram as many biscuits along an edge as possible. These are spaced on 3" centers. This corner is the only joint like this in the whole project and my goal is to get it clamped up so the glue can set overnight. Then I will build the rest of the cabinet around it.
Sometimes I put hardly any glue in a joint and sometimes I glue everything. This one is half and half. I don't want lots of glue showing up on the interior of the cabinet so I go light on the up side of the joint, and hopefully I only have a few bubbles poking out when the pressure is applied.

 The bottom side is much more messy and as strong as can be.

See you tomorrow!

One more thing, I was going to tell you why I started with the doors first. Solid wood moves with changes in ambient humidity. It never stops moving. Even with a heavy finish, it's progress in one direction or another is only slowed down, but never stopped.

By starting with the doors and other solid wood parts, I can monitor that movement in the shop for the longest period possible. I'm never really confident that movement has been properly accounted for, which explains my apprehension. I think it also explains why I have so few troubles down the road...knock on solid wood!

If you have any questions or comments about Mr. D's Walnut Wall Unit, please post them at the Info Exchange.

Jim Mattson

 Onward to the Next Installment

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