Case construction advice needed

[Len Rosenberg]

I'm building a tool storage case out of 3/4"oak. The sides are 16" deep and 6 1/2 feet tall. All the shelves will be adjustable except the middle one, which I want to make permanent to add rigidity.

I was thinking of joining the middle shelf to the case sides by a sliding dovetail, but the shelf is 36" long and the thought of running that vertically on the router table to cut the dovetail ends scares me.

The easy way would be just to use a dado joint and add screws through the sides into the shelf, but I'm a bit of a purist and don't want to do that.

Any suggestions on how to rout dovetail ends on a 36" long board, or a different way to permanently join the middle shelf to the sides besides a dado?

Thanks.

Len

[stevo wis]

Len, I just saw a tool chest and what they did with the horizontal shelf was to cut holes through the sides near the center. There were three or four square holes 3/4 x 3/4. Then cut matching tabs on the end of each end of the shelf and fit them into the holes. Slice them vertically and drive in a wedge. Instant dovetail.
Stevo

[Joe A Faulkner]

Four suggestions for you to consider:

1) Glue cleats to the sides, and screw the shelf in from the bottoms of the cleats. You could also run a stretcher across the back for the shelf to rest on. Drill over sized holes in the cleats to allow for some movement. If you are making a face frame, you could also incorporate a stretcher in the face frame and add cleats to it, or rabbit it for the shelf to rest on.

2) Run a stretcher across the back and front, and use buttons to attach the shelf.

3) Rather than a fixed shelf, make two cabinets; make the lower cabinet 20" deep and 48" tall, and the upper cabinet 16" deep and 30" tall and just go with a chest on chest kind of look - no fixed shelves - just two cabinets.

4) Forget about the fixed shelf - Add a face frame; it will be plenty rigid - especially if you place three stretchers across the back.

[Len Rosenberg]

That sounds interesting, but how do you cut 3/4" square holes in the sides???


Len, I just saw a tool chest and what they did with the horizontal shelf was to cut holes through the sides near the center. There were three or four square holes 3/4 x 3/4. Then cut matching tabs on the end of each end of the shelf and fit them into the holes. Slice them vertically and drive in a wedge. Instant dovetail.
Stevo

[Len Rosenberg]

Thanks Joe, I thought about the cleats, thats the easiest but least elegant solution. I might end up there, though.
Options 3 and 4 are out, no face frame, and the parts are already cut.
What do you mean about option 2, the stretcher?

Thanks,

Len



Four suggestions for you to consider:

1) Glue cleats to the sides, and screw the shelf in from the bottoms of the cleats. You could also run a stretcher across the back for the shelf to rest on. Drill over sized holes in the cleats to allow for some movement. If you are making a face frame, you could also incorporate a stretcher in the face frame and add cleats to it, or rabbit it for the shelf to rest on.

2) Run a stretcher across the back and front, and use buttons to attach the shelf.

3) Rather than a fixed shelf, make two cabinets; make the lower cabinet 20" deep and 48" tall, and the upper cabinet 16" deep and 30" tall and just go with a chest on chest kind of look - no fixed shelves - just two cabinets.

4) Forget about the fixed shelf - Add a face frame; it will be plenty rigid - especially if you place three stretchers across the back.

[Mike Schuch]

Use your router hand held with a fence mounted to the bottom. It will be easier to run the router over the 36" board than the board through the router table. You can even make the fence out of a simple block of wood.

[Bill McNiel]

Domino or biscuits.

[Jim Matthews]

+1 on using a free router and guide.

You could even make a sliding dovetail, that way.
http://www.sawmillcreek.org/showthread.php?223770-Sliding-dovetailed-shelves

[John TenEyck]

Screw a 12" tall piece of plywood, etc. to your router table fence. Then make your sliding dovetails in the normal way. The fence will support your shelf just fine; just make sure it's at 90 deg to the table. I've done things more than 4 feet long (high) that way w/o issue. The edge guide on a handheld router approach also works well.

John

[scott vroom]

I dado the fixed shelf with glue and clamps..don't see the need for mechanical fasteners in that application. I've done quite a few this way and haven't had a single one fail.

[Chris Padilla]

I would use my Domino as I gave up long ago on cutting dadoes. But if you don't have a Domino cutter, a spline might work. Also, as Scott suggested, simply gluing the dado would work just fine...no need for screws.

[Andrew Pitonyak]

That sounds interesting, but how do you cut 3/4" square holes in the sides???

Tricky, practice before you do it since it can be difficult to make it look perfect / pretty.

If I were to do it, I would probably begin by marking my through mortise locations, drilling by hand, and then using a chisel to pare to the line.

If you do use wedges, then that usually means that you have a slight taper on the mortise hole, however, so that when you pound in your wedges, the wood can spread and it will be locked in place. I don't think that I have seen this done on a book shelf before, but, I have seen a 1/8" deep dado to support the shelf and some mortises. The dado increases the weight-bearing abilities of the shelf. Of course, then you need to figure out how to cut those mortises. Oh, and it will flatten any cupping of the boards.

If you do this, however, the next question becomes; how many through tenons do you need or want?

If you create an "angle" in the mortise, you can just use a file (or similar) to create the slight angle.

if I wedge a tenon, I expect that a hole will be drilled through the tenon at the base of the line cut that will contain the wedge. (strain relief holes)

[Dave Richards]

That sounds interesting, but how do you cut 3/4" square holes in the sides???

You might want to have a look at Michael Pekovich's tool cabinet. He did something similar to what Steve described. The fixed shelf fits into a dado with mortises cut at intervals. The shelf, then, has tenons to go through the sides. Instead of slitting them vertically as Steve described, the tenons are slit horizontally and wedges. That way there's no stress on the grain of the case sides. See http://www.finewoodworking.com/item/57874/build-a-hanging-tool-cabinet

[Jim Dwight]

I would cut a dado about 1/16 to 1/8 deep mainly to aid glueup. I find it handier to locate the shelf when there is a clear place it goes. I would use through screws to hold it in position and plug the screw holes. I have a drill bit that drills the hole and countersink at the same time and plug cutters to cut up scrap for the plugs. Once you sand the plugs flush, they are hardly visible - especially if you look around for the right piece of scrap to cut the plugs out of.

If you don't like that idea, pocket screws from under the shelf would be my next choice. With the middle shelf below waist level, you wouldn't often see them. I've never tried plugging pocket screw holes but I've noticed they sell plugs for that.

[Peter Quinn]

I'd square up a chunk of 8/4 or a piece of 4X4 this length is a bit longer than the width of your case, clamp this to the opposite side of your piece, it supports the router, use an edge guide to set the depth of the dovetail, you really only need to dovetail one shoulder of the joint to lock things in. You can taper them if you add a shim to your clamped on block and reference the edge guide off of that, if you don't taper them either use a slippery glue like epoxy or slide them in most of the way then glue just the leading and tail end, or it will never go in with yellow glue. I have a pretty tall rigid fence for the router table so I wouldn't have a problem with that. You could also do this on a TS , tall fence, with the blade set back into the work, but thats a bit hairy if it tips. Its good practice, you can always glue in a corner block cut at a 45 set back 3 inches, nearly invisible, if things don't go well.

[Jerome Stanek]

When I read the heager I thought it was about Case construction equipment like Back hoes and dozers.

[Dave Zellers]

I really like the through tenons and wedges idea.

That's something a 'purist' would do.

Gonna have to do that myself someday.

[Len Rosenberg]

Thanks for all the great ideas and suggestions. Isn't it amazing how many different ways there are to approach and solve a problem in woodworking? Limited only by the extent of our creativity.

Len

[Eric Shapin]

If you want to use the dovetail joint on the long shelf, you can either create a simple fence from plywood (12" tall vertical portion, and perpendicular base that is long enough to be secured to the table with clamps. Also fasten right angle backings - plywood again - on the rearward side of the fence and the base for support), or you can clamp a 12" piece of plywood to your existing router fence. I built Jeff Miller's Cherry book case as shown in Fine Woodworking video series (see link) and, while Miller built the simple fence described above, I used the clamp-on plywood. At no time did the shelf, standing on end, feel wobbly or insecure during routing (this project used a tapered sliding dovetail, but the routing issue that concerns you is identical). Check it out.

http://www.finewoodworking.com/item/57001/build-a-classic-cherry-bookcase

[Joe A Faulkner]

Run a 2.5" wide board across the back of the cabinet, and another one across the front, you could attach them to the case sides with hidden dowels, or you could screw them in and plug the case, or run dowels all the way through the case. On the inside of each of these stretchers/rails, run a groove for button blocks, and use the button blocks to "clamp" the shelf to the stretchers. Here's a picture from Sean Hughto that illustrates the use of the button blocks in attaching a table top to a frame.

http://www.sawmillcreek.org/archive/index.php/t-215055.html


I think a simple dado would likely be more appropriate in this case. How are you joining the top and bottom to the case?

[Keith Weber]

The only reason that 36" held vertically on your router table scares you, is that your router table fence isn't tall enough. Build a cheap, braced fence out of MDF and clamp it to your table. I built one about 12 years ago for a project, but it gets used all the time. I'm guessing that it's about 10" tall or so, with about a 6" deep base. A setup like that would be more rigid than using a handheld router, so your dovetails would likely be more consistent, but handheld with a proper vertical fence would be my second choice.

[Jerry Olexa]

Many different solutions to a common joint..Do what you like but keep strength in mind...