Drawer bottom design

[dan sherman]

What’s a good rule of them when dimensioning drawers?

I’m building some drawers, out of ½” Baltic Birch that are going to be heavily loaded. I’m unsure how far from the bottom of the drawer side the dato should be (A) and how deep the dato should be (B).

What’s a good rule of them when dimensioning drawers?

http://img80.imageshack.us/img80/8433/dadoqu2.jpg


Is it better to rabbet the drawer bottom to save a little space, or should the dato be as high as the drawer bottom?

Thanks,
-Dan

[Joel Goodman]

I usually dado the sides and rabbit the back so that the bottom slides in -- i believe this is the standard detail -- that way the bottom could be replaced if needed in the future. The dados give the bottom strength that doesn't rely on fasteners. As to how deep I guess a "healthy" 1/3 or a little more of the thickness of the side material -- I just go by what looks right. On the bottom I'd leave at least 3/8" (past the dado). I'm interested to hear what others say.

[Jim O'Dell]

I'm also interested to see what the experts say. On the drawers I just built for my router table to hold bits, I left about 1/4" of material below the dado, and went about 1/2 of the way into the material. None of these drawers will carry a lot of weight. If heavy objects were going to be used, I think I'd leave about 3/8" material, especially if you're using Borg BB ply like I am.:eek: Jim.

[Joe Chritz]

I have always used 1/4" on all the ones I have built. Sides and front dado and the back cut short.

I also glue the bottoms in although I doubt it is necessary or even desirable.

Joe

[Danny Thompson]

My rule of thumb is A = the thickness of the bottom. This applies whether the bottom is rabbetted or not (assuming the bottom will be installed rabbet-down).

So, for a 1/4" bottom without a rabbet, A = 1/4". For a 1/2" bottom with a 1/4" rabbet, A = 1/2". This second option results in less sag (due to bottom thickness) and provides more support under the dado (1/2" v. 1/4"), but sacrifices 1/4" of drawer depth. Either way, I end up with a 1/4" gap under the bottom.

Does that help?

[Jim Becker]

If you use under-mount slides, that will affect your design--some have specific requirements for dimension A. I typically have dimension A 1/4"-3/8", depending on the drawer size and bottom thickness. The grooves normally are 1/2 the thickness of the drawer side and are the full thickness of the bottom. At least for any drawers I make.

[Paul Girouard]

On 1/4" bottoms I leave 5/16" to weak 3/8" . 1/2" bottoms I leave 1/2" plus / 7/16th scant.

I generally use what up here is called Euro ply , which they tell me is like the Apply ply we used say 7 to 8 years ago.

Never have used Baltic Birch in all these years , always cost more for a 5x5 sheet than a 4x8 sheet of Euro or Apply ply. 7 less sq. ft. for more money just never added up to me.

Jim has a good point on the bottom mount slide they will force you into a set depth and they also will provide some additional support to the draw bottom as well.

I also do the slide in bottom mentioned earlier, I screw the back edge of the bottom into the draw case back for the 1/2" bottoms , added hold power to accommodate the added weight.

[dan sherman]

Thanks for all tips guys. Since the sides and bottoms will all be 1/2" ply I will make A 1/2" and B 1/4".

[David Freed]

I make random length drawer side material for several Amish cabinet shops. The majority of them use 1/4" plywood bottoms and have us make A-1/4" and B-1/4". When they get an order to use 1/2" plywood for the bottom they do have us increase A to 1/2".

[Lee Schierer]

I routinely use 1/2" poplar for drawer sides and 1/4" ply for drawer bottoms unless the drawer is large and going to hold lots of heavy stuff. You used to be able to get 3/8 plywood, but I haven't seen that in years. I dado all four sides of the drawer 3/8" for "A" and 1/4" for "B". In my drawers the drawer bottom is locked in by the four sides. I've seen drawer bootoms fail because the back wasn't secured in place well enough and it sagged under the weight. In the event it would ever need to be replaced the back can be cut out rather easily along the top of the dado, so the old bottom could be taken out and the new bottom slid in.

[frank shic]

dan, are these drawers for the shop or for the home? if you want a real strong drawer bottom, you can butt joint a piece of 1/2" to the bottom of the drawer box. it's not the prettiest thing in the world but if you're planning on using epoxy coated slides, the slides will cover up the bottom edge. this is one of the great ideas i found in danny proulx's book on building kitchen cabinets. it'll also make your manufacturing process easier - no dados to cut! the other option is to use solid wood that's been bevelled to fit in the dado.

[scottj owen]

When we build drawers we always make measurement A 1/2" and measurement B 1/4", allot of our drawers are made out of white melamine, the particle core is quite abit weaker, you could probably go 3/8" for measurement A with baltic birch.

[Steve Clardy]

My standard is 1/4"
3/8" up from the bottom, 1/4" in on half inch sides.


Heavy bottom for pots and pans, I use 1/2 material, with a 1/2" groove.
Still 3/8" up from the bottom

[Gary Keedwell]

I made mine 1/2"(A) because my slides are on the bottom and the screws are 3/8" up from the bottom. My "B" dimension is 1/4"

Gary

[dan sherman]

dan, are these drawers for the shop or for the home?

These drawers will be for my shop. I’m into several different things (metalworking, welding woodworking), so I’m designing some modular storage units that can be configured as work bench ends, or as role away tool chests. The skeletons will be of welded steel and then skinned with ply.

The drawers themselves are 16 ½” w by 18 ½” d. They need to be pretty strong as they will be holding my metal lathe tool along with various other items.

for slided I'm currently considering these (http://www.thehardwarehouse.com/product_info.php?cPath=1_73&products_id=372).

[frank shic]

ball bearing drawer slides will work REAL WELL with heavy loads. good choice!

[David Giles]

Dan, once upon a time I decided to build big shop drawers as fast and easy as possible. Each drawer was 33" wide by 16" deep x 18" long. Each drawer had an individual case made of 3/4" baltic birch that set on a metal rack. The drawer was made of 3/4" BB with a 1/2" BB floor rabbeted into the sides. Drawer height was 1/8" less than the inside case opening. The drawer bottom slides on the case floor. Shellac and wax finish lets everything slide easily. The tight tolerances let the drawer slide almost fully open. I store up to 150lb of slides, screw and cabinet hardware in each drawer without a problem.

If you want to try this fast and easy method, leave 1/2" on each side and install a wood spacer. If you don't like it, you can always trim 1/2" from the drawer top and add a drawer slide to each side.