Garage Storage Cab – 1/2″ ply shelves?
GettinTher
| Posted in General Discussion on
My father and I are planning to build a storage cabinet for some of his tools and supplies. Due to space restrictions, the general dimensions will be 6′ 4″ H x 20″ W x 24″ D. Our idea is to make the case from 3/4″ Birch ply with 1/2″ Birch ply shelves and back. The back would sit in a rabbet. The shelves would sit in dadoes cut into the sides and back. The front of the cabinet would be covered with a 1/2″ Birch ply door (no face framing).
We aren’t shooting for pretty but want to make sure it is good and sturdy. How does this plan sound? Is 1/2″ adequate for the shelves and door? Do we need to worry about sagging of the shelves or warping of the door? Any suggestions?
Replies
Can't comment on much absent a drawing- but the shelves may be a problem, depending upon the weight you plan to place upon them. 20" is a moderate span (30" is really the max I would advise), but if the shelves are going to hold heavy objects (not unlikely in a garage), then 1/2" may not be enough- 3/4" ply would be better (but not as good as 3/4" solid wood). You might be want to strengthen the shelves by applying a rabbeted solid piece to the front edge (will also hide the ply); supporting the back in dados as well as the sides of the shelf is a good idea.
BTW, dados in plywood aren't the most robust joinery- you may want to use additional fasteners.
As for the door, it likely will not stay true if it is just a piece of ply. Consider a frame and panel, with the ply (1/4") floating between the rails and stiles. If you don't want to bother mortising the frame, cope cut it and use dowels to reinforce.
Good luck,
Glaucon
If you don't think too good, then don't think too much...
Edited 9/3/2007 4:02 am ET by Glaucon
Edited 9/3/2007 4:02 am ET by Glaucon
gettinther,
I have two such cabinets they are both about 8' tall; one 24" deep, one about 12" deep. The 12" cabinet is great for supplies(finishing material)but a bit shallow for tool boxes and the like. The 24" is a bit too deep for supplies but good for cases, etc.
Both cabs have 3/4 birch sides and shelves with hardwood strips on the front of the shelves and case for strength....it only takes a few minutes and looks nicer too. I have double doors on each (frame and panel) with 1/4" ply panels....the backs of the cabs are 1/4" too.
GT ,
Any of many combinations will work nicely , some a bit better .
If I was building the same project I probably would use 3/4" for the shelves and door as well . You didn't say if the cabinet will be fastened to the wall ?
I would most likely use 1/4" for the back, and glue and use fasteners to the back of the shelves, if they were not adjustable .In the 20" span you will have little deflection or sagging if any with 3/4" shelves .
Typically the cost for 1/2" Birch is pretty close to the cost of 3/4" , so also I would use 3/4" for the door , the hinge screws will have more to bite into for that size door .
dusty
You might consider 3/4 plywood that can handle moisture from humidity. I got some from a specialty hardwood supplier . Regular plywood may delaminate in humidity.
I made a 8 foot high by 4 foot wide by one foot deep cabinet for my garage. I call it a pantry because it holds the overflow from the kitchen and the garage hardly freezes in the winter.
My cabinet was pretty much standard-rabbits around the back. Sides were dadoed for shelves. I used Titebond glue-the water resistant one with the blue label. I also made a table 10 inches high for it to sit on-keeps the winter melt from the cars away.
The shelves were made much stronger by putting in screws through the back; glue is used here too. A short 1 by one-about 8 inches long was added beneath the middle of each shelf (at the back-screwed and glued) to give strength. On the front I added a one inch wide by 3/4 maple board for increasing each plywood shelves strength.
The structural integrity of a cabinet is markedly aided by the back; also by a strong faceplate made with mortice and tennons. My faceplate of this type is attached to the cabinet with biscuits; the back is attached with glue and pins in the rabbit. Arrow makes an inexpensive electric gun that shoots in pins (small nails). You can get these at Home Depot -my store has these near the wood clamps and staplers. I have six doors with inset hinges. The garage is white so I painted the cabinet with white housepaint on the outside. The cabinet is attached to studs-about six screws.
This may sound like a bit much but it has all the bells and whistles for strength and longevity.
Based on all your feedback, we reworked the design. The result so far is based on your posts, and recent FWW articles--Jeff Miller's "Building Bookshelves to Last," which talks a lot about reinforcing to prevent sag, and Jan Zoltowski's "Quick-to-Make Tool Cabinet." See sketch below.
Rough dimensions: 71" H x 24" W x 24" D. I am not finger/box joint-ready, so we thought simple rabbets for the case, reinforced with brads, would do. 3/4" birch ply for the top, sides, and shelves; 1/2" for the door reinforced with a 3/4" ply frame(rabbeted and brad nailed) and 1/2" for the back (rabbetted and screwed). The shelves are reinforced with oak edging on the front and fixed in place with cleats. The cleats are screwed to the case and the shelves are screwed to the cleats. This should provide stability for the sides of the case and avoid the weakness inherent in plywood dados.
We split the door into top and bottom 1) to manage the weight of the door and all the hand tools we plan to hang on it, and 2) so you can access the majority of hand tools without backing out the car.
I added four 3" tall (2.5" deep) removable drawers/trays for hand tools or other items you might want to take to the bench as a set. They ride on cleats similar to those used for the shelves rather than on rails that fit into dados (Jan's design). They work by having drawer sides that are shorter than the fronts. Anyone tried this before? Pros/cons?
I figured a 20" deep shelf up top was impractical, so I incorporated Jan's hinged storage panel in front of a 12" deep shelf.
What do you think?
View Image
Edited 9/5/2007 6:04 pm by GettinTher
Edited 9/5/2007 6:08 pm by GettinTher
Edited 9/7/2007 10:47 am by GettinTher
Looks good. A few comments:
1) A 1/2" thickness on the back really doesn't buy you anything, unless you plan to screw into it. All of the forces on the back are in the plane, so as long as it's well glued along the perimeter, anything thicker than a piece of paper would do just about as well.
2) If you can beg, borrow or steal a biscuit joiner, it will make the case glue-up easier, as well as give a little more reinforcement to the corner joints.
3) Unless there is a compelling reason for it to be all in one piece, I would suggest making an upper cabinet that stacks onto a lower cabinet. Tall cabinets are unwieldy at best, and moving them around is so much easier when you can break them down into more manageable pieces.
-Steve (owner of several 7' tall bookcases, some of which can never go into certain rooms of the house, because there is no way to maneuver them around the corners)
One other thing comes to mind. Something like these:
http://www.rockler.com/product.cfm?page=10113
or these:
http://www.leevalley.com/hardware/page.aspx?c=2&p=51101&cat=3,43576
come in very handy when gluing up large plywood boxes.
-Steve
You might consider the piece be made in two sections. The bottom piece could be much deeper than the top. That gives you a small work area; also a storage area for larger tools. Two separate pieces make it easier to build-especially if you work alone. There are very few tall narrow single pieces in woodworking.
Joseph Beals did an article in the FWW book-Ingenious Jigs and Shop Accessories(year 2000)-about moveable cabinets which is another approach altogether.
Great suggestions. Follow-up:
Steve
1) 1/2" back v something thinner. I should have mentioned that I plan to add a short cleat attached to the back under each shelf to prevent sag in the back.
2) biscuit joiner. With every project I try to find an excuse to buy a new tool. The biscuit joiner is perfect. So, no rabbets in the case or doors then, except for the back? Biscuited butt joints instead?
3) 2 units. Sounds like a good idea. I'll play around with that.
Paul
Moveable cabinets. I was concerned about wheels on such a large cabinet. Unfortunately, we are horizontal space-challenged, so our only option is to build up. But, a top and bottom piece would certainly be more mobile.
"So, no rabbets in the case or doors then, except for the back? Biscuited butt joints instead?"
For the case, yes. (That's what I do, at any rate.) For the doors, if you look at Jan Zoltowski's cabinet, you'll notice that the door panel overlaps the frame pieces. If I wanted to use biscuits, I'd do it that way, so that the biscuits go into the edges of the thicker frame pieces, and into the face of the panel. (If you inset the panel into the frame, the biscuits would be going into the edges of the 1/2" thick panel, which seems a little less robust to me.) However, I've never made a door quite like that, so I can't speak from experience.
"Unfortunately, we are horizontal space-challenged..."
Lucky you. I am space-challenged in all three dimensions. ;)
-Steve
It looks good. The only thing is that maybe the base should be open to prevent moisture being trapped. The base could be mahogany or pressure treated.
The pulls on the door could be wood. I took a long scrap hardwood piece and shaped it on the router table, then cut it to length.
Building something like this can be so much fun that you can't stop and you keep making many variations.
I've been using this type of leveler:
http://wwhardware.com/catalog.cfm/ProductID/T2666%20LA
It does a good job of keeping the wooden parts dry.
-Steve
I have made 4 large cabinets with 40" shelfs in my garage with 3/4" MDF. I reinforce the shelfs with 1-1/2" faces to eliminate bowing. They have stood the test for over a year with fairly heavy items without failure. Additionally, the MDF is easy to work and takes paint well. I used 3/4 birch ply to make the doors. in roughly 20X40" sizes with no warping. Good luck.
simeonzera
Taking everyone's advice. Here is a 2 cabinet version.
2 cases of the same dimensions: 34" H x 24" W x 24" D. They are stacked with a 3" footer and a 1/2" spacer between the cases to allow clearance for the doors. This way, they are more mobile and can work side by side if I ever want to slide them under a workbench, for example.
I also changed from rabbets to biscuit joints everywhere in the outer case except the back.
Thoughts?
View Image
Edited 9/7/2007 11:09 am by GettinTher
Edited 9/14/2007 9:23 am by GettinTher
A quick note on biscuits in plywood. Try to keep them as low in the shelves as you can. They are acting in shear, and the plywood tends to separate on the glue joint between the plys. The lower in the shelf the biscuit is the more resistance to splitting you have. I would set the shelves flat on the bench and use the bottom of the biscuit joiner as the reference with out the fence. Pretty foolproof methodology.
I would also attach the shelves to the cabinet sides with screws, confirmats if you don't mind the heads showing from the outside, pocket holes from the shelves if you do. Shop cabinets take a lot of abuse and over loading.
With regards to casters on a piece this large; next time you are at a mechanics shop take a look at their roll-away tool cabinets, time they put a top box on them they are about six-feet tall, and loaded with heavy tools. I've never seen one tip over while on the floor. I have seen a guy who got fired for failing a drug screen, and his three drunken buddies lay one over while trying to drag it up a ramp into a pickup so they could get it out of the shop. But, I think that had more to do with drunken stupidity than any inherent instability of the cabinet.
I was wondering about that. I haven't used face frames in plywood, just in solid wood- do you really gain much in strenght given that only the biscuits are making a joint? Would splines (or anything) be better?
Glaucon
If you don't think too good, then don't think too much...
My plan was to attach the face frames to the shelves by rabbetting the face frames and gluing; I was not going to biscuit the shelves to the face frames. According to an article I read in ShopNotes, this method provides the best edge support.
I plan to use biscuits to join the sides, top, and front case pieces and, as suggested above, saw off the front 3 1/2" or so to make the door. The reason for the deep front is to add storage space to hang tools on the door.
I have yet to allow for the swing of the door, which would, ideally, open flush with the side of the cabinet. The problem is, if it doesn't swing wide, then the door edging will block the drawers/trays. Hmmm . . .
Other considerations: In my drawing, I rabbetted the face frames and the shelves, but the ShopNotes article implied that the shelf should be full thickness; only the face should be rabbetted. What is interesting is the sagulator (http://www.woodbin.com/calcs/sagulator.htm) suggests that shelves of this dimension (22 1/2" W x 20" D x 3/4 ply) can withstand well over 90 lbs of center load without noticeable deflection over time (.03 immediate + 50% with time, across 20"). Maybe I don't need the edge support after all.
I would put the front edge on the shelves, and put it up not down. This results in a "catch" lip on the front to help keep things from falling out.
Yes, I know you hve no intention of ever cramming things in there so tight they will try to fall out when you open the door. But things happen over time that change that attitude. Mostly you accumulate too many really good things that you just can't part with.
In plywood it is best not to disturb the faces anymore than you have to. The face veneers are the most stressed part of the plywoods structure. Think of it this way, if you cut a 1/4-inch deep dado in a piece of 3/4-inch plywood, what you have left is the strength of the 1/2-inch plywood you have left. The Dowels or biscuits minimize the disruption on the surface.
Dowels have their own problem in that they will disrupt more of the plys in the shelf, and reduce the number of plys above the joint that resist the shear load. This makes failure of the joint more probable.
When you load the shelf, the sides want to buckle under the load, since they can't go into the shelf, they will tend to go out. Thus my recommendation for screws to resist that force.
I'm an engineer, and have always had a tendency to design things by thinking about what pushes or pulls where, and what resists it, even before I took the classes that train engineers to think that way.
My worst woodworking peeve is dovetails that aren't orientated properly for the loads they will see. Every once in a while someone will post a picture of something with the dovetails orientated wrong. The worst I have seen was a bench with the tails on the end board where the end vise attaches. Every time he uses the vise they are going to want to separate. Or, blanket chests with the tails on the front and back, so that they want to pop out if you really load the thing full of blankets.
I still haven't figured out a polite way to tell someone who has invested a large chunk of both time and money to build their dream project that they just screwed the pooch.
Hiya Jigs ,
I beg to differ with you on your rating or opinion of a 1/4" deep dado cut into 3/4" plywood only being as strong as 1/2" plywood , it may look that way on paper but in the real world , not so if done right . The remainder of the dado would be the same thickness as 1/2" agreed , but it's only thaty thin for 3/4" .
If that is true then you could build a box of 1/2" ply and it would be as strong ??? I don't think so . The glue surface of the proper fitted dado would offer 1 1/4" of glued area plus the fact that the shelf would be captured and the weight of the shelf transfers in a downward direction for the most part . This type of joint about 2/3rds or over 60% additional contact surface and sheer shelf if you will , the dowels or screws or bizkits certainly have their place but the comparison is sketchy at best .
Also in conjunction with a face frame whose joints are glued together and glued to the cabinet front will reinforce the joints no matter which way we do it , don't you think ?
dusty ,,, a box builder by trade
Thanks to everyone's input, we built the cabinet with a much better design than we started with. You can see the final result in a separate thread: Tool Cabinet by Committee (38037.1 )
Thanks all,
Danny
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