Some guidance on first large piece

[Jared Cuneo]

Ok, so I've done a lot of boxes, a small M&T table, glued up a 1.75" birch strip bench top and base and a couple of shower stools and now it's time to move up.

LOML wants this: http://www.crateandbarrel.com/family.aspx?c=996&f=8889
(BTW, they are using tongue and groove for this? how?)

I'm going to build it from solid Ash and ebonize it ala Bubba's table, however, I need help on the wisdom of the joinery.

My 'plan' :)

It's 55" wide, 14 deep and 28 high. I never used sketch up before so forgive the crudity of the attached image. The shelves are adjustable and I planned on biscuiting or doweling the face frame to the main carcase but my main question involves the rigidity of the carcase. Will 4 biscuits shown be enough? The middle divider is half-lapped to the stretchers and rests in a dado on the bottom shelf. The back will be shiplapped 3/8" Ash 3-5" wide and secured with 2 screws per piece (upper and lower).

I was going to dovetail the stretchers into the sides but its a lot more work for something noone will see, and I was concerned the visible tails would finish differently than the Ash. If its going to vastly improve the strength, I will make the stretchers from Ash and DT them, I just have no idea what to expect.

The main challenge is the base joinery, what else can I do down there? My chisel skills are not the greatest and the thought of M&T'ing the bottom shelf into the sides is not particularly appealing, but again, if its a LOT better, I'll do it.....

Any advise for this first timer would be appreciated.

Thanks!

JC

[Jamie Buxton]

Are the sides, top, and bottom all solid lumber? And I'm guessing the grain direction of the sides is up-down, not horizontal as shown in your sketch. It is important to establish these grain directions because they strongly impact the joinery you're asking about.

If the grain directions are as I've guessed, the biscuits won't glue very securely into the sides. Glue bonds well to face grain, not to end grain. The sides of the biscuit slot are going to be end grain -- hence poor glue bonding. Similarly, any glue on the ends of the bottom will be on end grain. and won't bond well.

There are several joinery methods which work well for boards in that configuration. Here are a few:
* Finger joints
* Dovetails
* Miller dowels (Look 'em up. They're simple, and remarkably strong.)
* Through tenons
* Fake through tenons. (They're long screws covered by fake tenon ends.)

(And to answer your first question, I don't see any tongue-and-groove joinery in that Crate&Barrel piece. I think the ad writer doesn't know much about woodworking.)

[George Carion]

I think the person who wrote the description meant mortise and tenon... not tongue and groove.

Maybe attach the face frame via dowels? Might be tough to line up though.... or skip the face frame altogether. It looks the face frame is only there to cover up plywood edges. I think most of the strength of the unit will come from the back so the face frame wouldn't be as important. I'm an amateur though and I'm sure more knowledgeable people will chime in.

Good luck!

[Jared Cuneo]

Dovetails on top stretcher and Miller dowels through lower dados or should I just bite the bullet and cut through tenons for the lower outer sides? I'm also changing the sketch to show the middle divider extending down to serve as a third 'leg' and changing the back to 1/4" ply.....

Oh and the face frame, I think it gives the case a more substantial look, maybe I will just join it via biscuits.....especially with all this new work :)


Any more ideas or input?

THANKS!!!

JC

[Jamie Buxton]

This is just me, but I'd use the same joinery at the top as at the bottom. That is, if you're going to use dovetails at the top, use them at the bottom. Or if you're going to use Miller dowels at the bottom, use them at the top. There's no structural reason backing this up -- just personal taste.

You can use biscuits to position the face frame as you glue it on to the carcase. They don't really change the strength; the glued butt joint between the case and the face frame is quite strong. The biscuits help register the face frame on the case so that it doesn't squidge around when you're putting clamps on. (Me, I find biscuits much easier to use than dowels. I can't ever get multiple dowel holes to line up.)

Changing the back to plywood from ship-lapped lumber makes the case somewhat stronger. The plywood better resists sideways racking. If it is going to disappear from sight behind books and such, there's little downside. However, the veneer on the plywood sometimes takes stain differently than solid lumber does. You might test your proposed finish before you back yourself into a corner.

[Jared Cuneo]

Thanks for the input Jamie, one question however. The lower shelf is 2in up from the bottom, how would I dovetail that end. It's looking more and more like the Millers for both ends :) Hopefully they will be strong enough.....

JC