I’m building some drawers for kitchen cabinets that will have 1/2″ baltic birch bottoms. Why is it that most drawer designs (regradless of how the corners are joined) do not capture the back edge of the bottom in a dado? The designs I know leave the back shorter than the sides, with the bottom slipping into the dados of the sides and front. The bottom is then fastened to the back. This is a lot of words, but you get the idea.
I am considering making the drawer backs with a dado so that all edges of the bottom are captured. I guess that the assembly will be a little trickier, but not much. I suppose that I will have the bottom float completely, right? Does anyone see any problems with this?
Thanks for your help.
Replies
That is how I usually do it. I cut the bottom a little small so it can move in the dados.
Frank
Dogbat,
Frank is correct. Originally the drawer bottoms were not captured all the way around. This was so it could expand with the weather without pushing the drawer apart. Typically the grain in the bottom was oriented across the drawer, i.e. parallel with the front. The front edge of the bottom was usually, but not always, glued into the groove in the drawer front. (Obviously the front was the only bottom edge that was glued.) Cutting off the groove in the back of the drawer, as you described, and nailing the drawer bottom to the bottom edge of the back, allowed the wood to move.
I too don't always make drawers in the traditional way. I often do as you plan to do: capture the bottom on all four edges. Plywood, with a couple coats of shellac, won't move nearly as much as a solid wood bottom. So far so good. No drawer I've made this way has ever come apart. I lose my courage on large drawers though, and usually do it the old-fashioned way. No good reason. Sheer cowardice, I guess.
BTW, a half inch plywood bottom? That seems awfully heavy. When using plywood I've never made a drawer bottom thicker than a quarter inch--except the bottom drawer of my rolling tool chest. But that was not a design choice; I ran out of quarter inch ply. On period pieces or when restoring an oldie, if the other drawers are so made, I will make a raised panel for the bottom. That's one way to get extra strength in the bottom while keeping the grooves narrow enough that they don't complicate cutting the dovetails. But again, unless you're storing your gold ingots in the drawer, IMHO half inch ply seems awfully thick.
Alan
Frank and Alan,
Thanks for your comments. I know what you're saying, Alan, 1/2" is definitely overkill. I'm doing it because the drawers are relatively wide (26", 30" and 40") and we will be storing heavy plates, small boulders, solid cast iron ingots and all the other junk that accumulates in our kitchen. I have definately seen 1/4" bottoms sag in wide, fully loaded drawers.
More questions: I am debating whether to cut a rabbit along the sides of the bottom so that I can use a narrower dado. Any thoughts?
Also, how much wood movement should I allow for a 23" deep drawer bottom (1/2" baltic birch).
Lincoln
Hi Lincoln-
I build lots of drawers, and although I usually use 1/4" ply for bottoms, I do agree that the wide drawers you're talking about (30", 40") could benefit from the extra strength of the 1/2" ply, especially if heavy objects are going to be stored. A little overkill here and there generally can't hurt.
In response to your question:
Also, how much wood movement should I allow for a 23" deep drawer bottom (1/2" baltic birch)?
The answer is none, since plywood doesn't expand and contract the way that solid wood does. I would cut the bottoms to fit snugly in the dadoes so that you have plenty of surface area for glue to bond with. A plywood bottom doesn't need to float: in fact, by gluing it in, you strengthen the drawer and help to ensure that it will remain square over time.
More questions: I am debating whether to cut a rabbit along the sides of the bottom so that I can use a narrower dado. Any thoughts?
Yes: Why would you do want to use a narrower dado? I can think of 2 reasons, but neither one ends up really being significant.
1) You're trying to save the time of making multiple passes in cutting the dado (i.e. you're using a router bit or tablesaw blade that is narrower than the 1/2" drawer bottom). You would save some time this way, but that is quickly cancelled out by having to set up for the rabbeting on the drawer bottoms.
2) You're worried that a 1/2" dado removes too much material from the drawer sides, thus weakening the drawer. I don't know how thick your drawer stock is, but I usually use 1/2" solid wood or BB ply for kitchen drawers, and I cut dadoes that are 1/4" deep (leaving 1/4" of thickness in the drawer side). With a snugly fit drawer bottom and plenty of glue, I don't have any concerns about strength here.
I may be missing something- if so, I'll look forward to a reply to set me straight. Hope this helps.
Best, Chris Gleason
Gleason Tableworks
http://www.interestingfurniture.com
Hi Chris,
Thanks for the informative response. I thought (but I've never tried to verify it) that although plywood moves much less than solid wood, that it does move a little. I know that it's recommended to leave a 1/8" space on a 4X8 roof sheet. I suppose that is a very different situation since the drawer will be sealed on all sides, where the roof sheet is not.
I am using 5/8 BB for the sides, subfronts and backs. My somewhat warped thinking was that if I rabbit the bottoms, I would lose less drawer volume because the bottom could be closer to the bottom of the sides. I would prefer not to rabbit the bottom and your response supported that idea. I have the tools to make the side dados the right width for the 1/2" BB, either on the table saw, shaper or router table.
I was going to allow 1/2" between the bottom of the side dado and the bottom of the side. Is this overkill; can I use less and not worry about weakening the drawer?
Thanks again,
Lincoln
Lincoln,
Your idea about cutting a rabbet along the edges of the bottom is basically what I sometimes do for drawers on period or old pieces: you would, in effect, be making a raised panel. If my steadily fading memory has not entirely deceived me, I believe this was commonly done by the Shakers. That speaks for itself.
Are you going to join the sides to the front of the drawer with half-blind dovetails? If so I would go ahead and cut the rabbets; that will make it much easier to cut the groove in the drawer front so it emerges in a space for the tail (so it's covered by the tail and doesn't show). It's much simpler to place a 1/4" groove entirely within the tail-space than a 1/2" groove. But if you're going to use some other joint it might not be worth the effort (how's that for equivocation?).
Alan
Alan,
Your comments make sense to me, but I'm not doing such a sophisticated job. These are utilitarian kitchen and pantry cabinets and for the 45 drawers I need, I'm just not ambitious enough to consider dovetail joints; blind or not.
The drawers I'm making are simple boxes, with sides of 5/8 BB and bottoms of 1/2 BB. I'm trying to make them as strong and durable as possible within the limits of the materials and the time I have available. I'm using offset tongues for the corner joints. They will have an applied front of 1" soft maple and full extension Accuride slides.
Lincoln
Well friends, with your help I cut the first dozen drawers and assembled one of them. The final design has a 31/64 wide X 3/16 deep dado all around the 5/8 BB sides to receive the 1/2 BB bottom. The bottom is cut with a total of 1/32 clearance in width and depth 'cause I gotta allow something for all those tolerance stack-ups. The bottom is glued all around and the sides are glued and finish nailed. The pieces of the one I assembled fit like a glove...very slick. I'm happily looking forward to cutting and assembling the rest of them later this week.
Thanks again for the advice.
Lincoln
Hi Lincoln-
Glad to hear that the drawers are shaping up! And of course, we love pictures around here if you get bored once the job is done...
Best,Chris Gleason
Gleason Tableworks
http://www.interestingfurniture.com
Chris,
Photos...how do I do that? With the "Attach Files" option? Do they show up in the post or through a link? I'll take some digital photos as I go and send them.
Lincoln
Lincoln-
I think that the best place to upload photos is in the "Gallery" section (I'll admit, I've still never uploaded any!) If you go there, I think at the bottom of the window when you type a new message, you'll find an "Attach" button for photos. This also might be wrong. I'm sure somebody could pipe in with some advice?Chris Gleason
Gleason Tableworks
http://www.interestingfurniture.com
This forum post is now archived. Commenting has been disabled