Q on BB Ply box construction -- Final Result

[Doug Shepard]

After discovering some pretty significant surface rust on my Powermatic Tenoning Jig, I decided it's time I made a box to store it in. While I'm at it there are one or two other tool accesories that could also benefit from having storage boxes, but the TJ box would be the biggest - 9H x 14D x 22L (interior dimensions). I'm planning on using 1/2" BB ply and using box joints (finger joints) to join the 4 sides. I'll either overlay the top onto the sides or set it into a rabbet. My question is on the box bottom which I'm also planning on making from the 1/2" BB. I'd like to avoid the extra height required to set the bottom into a dado if possible. Can I get away with setting the bottom into a rabbet or using biscuits so that the bottom is flush with the box sides? The weight of the TJ is around 20 Lbs.

[Jim DeLaney]

I'd flush-mount it with the biscuits. Probably use #10's in the half inch stock. Three along the 14" sides, and four or even five along the 22" sides ought to be substantial.

[Jamie Buxton]

If you cut everything to the right size, a glued butt joint between the bottom and the sides is sufficiently strong. Remember, this is plywood, so there's a lot of faceg-grain to face-grain area in the glue joint. Biscuits are a good way to keep eveything lined up during the glue-up. Another way to keep things lined up is the lock tenon joint. I use it all the time in baltic birch (or applyply in my case). You make it with just a few passes on the table saw. I'd even use it at your box's corners instead of making finger joints.

[Doug Shepard]

Thanks guys. I was a little concerned that the weight might be too much for the relatively small glue surfaces involved, but think I'll go ahead and do the biscuit thing. Something about relying on glue alone for this just nags at my sense of paranoia that my TJ could come tumbling out the bottom of the box if the glue gods aren't in my corner. I know it's not much but the biscuits seem to have at least some mechanical hold (however minimal).
Jamie - do you have a link to something with pics of a lock tenon joint. I know I've probably seen this somewhere, but I'm just drawing a blank.

[Clarence Lau]

http://images.scrippsweb.com/DIY/2005/11/07/dit337_1ca_e.jpg

I am not 100% certain if this is a "lock tenon", but according to his descriptions, the above is actually achievable by using a table saw with the right dado blades setup (Edit: apparently you can also do the same with multiple passes on a regular blade; or a router table too). Hope it helps.

DIY Lock Joint (http://www.diynetwork.com/diy/hi_tools/article/0,2037,DIY_13936_4219278,00.html)

With Aloha,

Clarence

[Todd Burch]

1 lock joint example.

[glenn bradley]

Todd B.'s example will only cost you 1/2" in extra height and yield an inch of glue surface vs. the 1/2" of a butt joint plus the mechanical strength. Unless your TJ weighs a lot more than mine, bicuits should be plenty if you're more comfortable with them.

[Joe Jensen]

If you can spare the room. Put some blocking in the corners. I cut 3/4" by 3/4" square strips, and then rip them to make two triangular pieces. I put them inside where ever I have space, ideally on each joint. These add tremendously to the strength without taking much space inside the box.

[Larry Cooke]

Here's yet another idea. :) Visualize Todd Burch's example but turn the right side up, then imagine the back as the bottom. I imagine that's what was originally suggested. Hope this makes sense...

In other words, cut a 1/4" rabbit 1/4" up from the bottom edge of each side and front/back (like you might do if you were to slide a 1/4" ply bottom in.) Then cut a 1/4" rabbit in the bottom (1/4" x 1/4") on all four sides and then you've got a super strong bottom. Might interfere with the box joints but then this is a utilitarian box right?

Just another thought...

Larry

[Doug Shepard]

Todd/Larry - Glad you piped in as I hadn't thought of using a rabbetted bottom panel into a dado. I think that's what I'll end up using. I'll still get the mechanical lock of a dado but with the bottom flush with the sides, plus more glue surface too.
I was originally thinking biscuits or rabbeting. Biscuits just cuz they're fast and this is another project that popped up that wasn't really in my plans. Rabbeting would have been pretty quick too but neither method seemed to have much going for it mechanically. I was thinking along the lines of rabbeting 1/2" deep and inserting the whole bottom pc into the rabbet. I like your idea better.
If I was working with 3/4" BB I think the lock rabbet joints would be great. That's what I've always called them, and maybe that's the same thing Jamie was referring to by lock-tenon (?). But in 1/2" ply I cringe slightly at the thought of the 1/6" thickness on the projections. Murphy's laws says at least one of those is sure to get accidently snapped off before I get things glued together.

[Doug Shepard]

Well I ended up using the joint Todd and others suggested for the bottoms , kept the box joint idea for the sides, and just got the last of the hardware put on the boxes this morning. I did the box joints with my CNC (Crappy No Cost) jig and dado blade. All told it ran me about $75 to make all four. The sides are 1/2" BB ply. The bottoms are a mix of 1/2" BB and 1/2" MDF (ran out of BB ply). The tops are a mix of scrap of 3/8" BB or 1/4" Luan ply I had lying around.

A week or so ago, I was asking about some rotary draw latches like those on ice coolers.
http://www.sawmillcreek.org/showthread.php?t=38231
Wasn't haven't a lot of luck finding anything affordable that looked like what I was after. But when I went to the Borg to get a piano hinge I realized.. DUHH. Rotary draw latch = sash latch. Found a low profile sash latch that was pretty darn close to what I had in mind. Picked up the cheapest handles I could find. Finish is 1 coat of SealCoat + 2 coats of Minwax wipe-on poly + a cat hair or two.

Systainers they aint, but at least they'll keep the rust off some tools.

41855

41856

41857

41858

[Larry Cooke]

Finish is 1 coat of SealCoat + 2 coats of Minwax wipe-on poly + a cat hair or two. :D

Gotta luv them cats when painting or finishing huh?

Doug they look great and like your idea on the latches too, job well done!

Larry