I have been asked by a friend to make 2 sets of bookcases for her. They will be made of cube shapes, that sort of make a step pattern. From left to right, you would have 1 cube, then 2cubes, followed by 3 cubes. She wants 2 bookcases that are mirror images of each other for her twin boys.
I included a quick drawing of the front view of one of the units for reference. I would like to make them out of plywood but I can’t figure out a way to hide all the edges. I know on the front I can make a face frame, but there will be visible joints on the top view of each cube.
Any ideas on how to hide all the exposed plywood edges? Or if I was unclear in my explanation let me know so I can clarify.
Replies
I cant seem to view your pic, but think I understand what you're after. I usually glue on hardwood edging to ply whenever I make something from hardwood veneer ply.
If you build it he will come.
Are you planning to paint these cubes?
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"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Hi Bill,
How about making the plywood boxes using mitre cuts along the edges, reinforced with splines. Lon Schelining used this approach in a recent issue of FWW to make carcasses for a workbench he built in a previous issue. I'm assuming that the boxes will be made with 3/4" plywood.
The mitres will eliminate any visible plywood edges on the outside corners of the boxes. If you are going to apply a back to the boxes, you may want to rabbit the back sides first.
Once the sides are cut, using the tablesaw still set to 45*, cut a mortise in each of the mitred sides to accept the splines. The mortises should be slightly wider/deeper than the spline stock by about 1/8" to 1/4" and placed near the inside of the mitre where you have the most width. Make up spline stock that is the length of the sides, minus an 1" or so.
Apply glue and lay the pieces on a flat surface, outside up and tape the pieces together while applying enough pressure to hold them tightly together. Then simply stand the pieces on end and wrap them to form the box. If you thiink 4 pieces are too much to handle at a time, do 2 at a time then glue the halves together.
Next, cut the splines in half. Apply glue to the splines and insert the halves from each end. This will ensure that excess glue is pushed into the middle and minimizes any potential squeeze-out.
As far as the front plywood edges are concerned, these could be accomodated with a face frame as you suggested (might be rather complex), or face them with veneer.
Best of Luck,
Bob @ Kidderville Acres
Use whatever tool needed to Git 'r Done!
I might have found another way that I can do it. The horizontal pieces that are the top and bottom of each section can be made out of solid wood rather than the plywood. If I were to put a rabbet in the top of each piece of solid wood to accept the plywood side panels, I think that will keep the plywood edges hidden. Still need a face frame on the front, but I figured that I was going to need that no matter what I did.
Don't do this. Either use solid throughout, or the plywood throughout. Otherwise the differences in movement will cause your boxes to self-destruct. If your tablesaw is up to it, I'd use the mitered corners as suggested.
DR
Edited 2/14/2006 12:16 am ET by ring
Thanks Ring. I had overlooked the wood movement issues. I want to keep the costs down so I'll probably end up trying the miters. I was worried that it wouldnt be strong, but the splines should do the trick. I've never tried them though.I'll ask the customer what wood she wants, and that might make the choice between all ply or all solid a little easier. If she says, pine, then solid it is.
Bil, The spline material as suggested in previously posts are oriented with their grain parallel to the grooves They tend to split too easily, Rather, use splines cross grained. Before gluing the open cubes, have some flat right angled corner plates ready to align the boxes square and secure with masking tape
Steinmetz.
Hello Bob,
I studied the article that you cited. It is a great way to get strong joints in plywood. And it has another feature.
If the grain of the face veneer is running perpendicular to the seam, its end grain my suffer damage from incidental bumping. But routing a shallow, narrow groove along the outside corner of the seam allows you to glue a hardwood strip there and protect the exposed edge of the veneer. It is cockbead, but on a corner, rather than along an edge, as is more usual.
Thanks for the suggestion, John
John,
That's a great idea! I'm going to incorporate it into the boxes/carcasses I'm building for underneath my workbench. They're sure to need the extra protection you suggest.
Thanks,
Bob @ Kidderville Acres
Use whatever tool needed to Git 'r Done!
I have built many edge-hidden drawers and boxes from plywood using a lock mitre joint created on a router table. The narrowest plywood that this techique works on is 1/2 inch (but that's a struggle). Lock mitre joints work great on 3/4 or 4/4 inch ply.
You need to use good quality birch ply or similar (no voids, minimum knots, etc.). Also, the glue makes plywood a hard material, so use 2 - 4 passes to cut each jointed edge.
If you want really neat corners, these factors are critical:
* Do test runs on bits of ply until the horizontal and vertical joints meet perfectly on the inside and outside corners. Save your succesful test pieces to use in setting up the router table/lock-mitre cutter next time.
* Route slowly and carefully. It's easy to allow the workpiece to wander if you do not use hold downs, which ruins that piece. This is particularly difficult if you are cutting a workpiece vertically (edge-down) that is higher than 12 inches or otherwise unwieldy.
* Also, breakout can occur at the end of the workpiece, especially with the sometimes brittle end-grain layers within plywood. (If you use over-long work pieces, you can cut the last 1/4 inch of SOME of them to remove such breakout - but this is not possible with panels which must be jointed with two or more edges meeting at a corner). You can also cut one large piece then rip/crosscut it into the smaller pieces for your project.
* Some of the middle tongues of the lock mitre joint can sometimes break off in parts, if that tongue happens to be formed on a ply layers that show end grain. As long as there is some tongue left, this doesn't seem to weaken the glued-up joint much. (You can sometimes also recover larger broken-off bits of tongue and glue them back in place). Use ply with many thinner layers to avoid this problem.
* Orient the lock mitre joints so that the tongues of the joint take the stresses on the furniture at a right angle. Put another way, make sure the main forces acting on the furniture cannot pull the lock mitre joint apart mechanically, even if the glue fails. (Of course the glue won't fail, but it's always best to ally glue strength with mechanical strength). For example, drawer front pieces are always cut with the lock mitre tongues parallel to the drawer front; and the drawer sides have their tongues cut to match (ie also parallel to the drawer front).
Open-sided boxes (drawers, bookcases) need the open edges left uncut and lipped. Closed boxes can be jointed so that the plywood edges are completely hidden. I once built 40 12x6x6 inch (money) collection boxes like this and they looked almost too good for such a mundane purpose. I nearly used then to make a cubist chair for the younger grandchild, the only person who would have fit into it (kidding).
Bob,
Your suggestion of splined miter joints is a good one. I tested such a joint in 1/2" plywood and found it was really strong. See my post of yesterday in "Protecting the edges of veneer."
Bil Me again. Why not forget the splines and grooves? Since each section consists of six open face cubes,why not cut thirty square sides first with the saw blade set at exactly 45 degs?
Lay the four sections on a flat surface and tight against a straight edge with all four faces up and tight together (Beveled sides down)
Then using masking tape, bind the joints as if attaching hinges.
Turn the four hinged unit over and apply glue to the bevels then 'roll' the unit to form a box and secure with more tape
After all glue is dry attach all the rear panels likewise.
That leaves you with the cube's fronts mitered and ready for SOLID wood 3 cornered (right angled) molding. ( Of which can also be ripped on the table saw and mitered on a miter box. Steinmetz
To avoid the 'bulky' look, use 1/2" or 3/8" ply for cubes
When assembling and gluing the units, keep all the grains in the same direction all around each box Now get to work and send photos Steinmetz.
Edited 2/17/2006 2:51 am ET by Steinmetz
Bill...what ever method you choose to design your bookcases, just remember that "anything worth building is worth building well." Trying to save money should always be considered but don't let it compromise your design. If you factor all your time, the use of your tools, and the materials (a decent grade plywood isn't 'cheap'), then you have already tallied up to a walmart-style price, so then the question becomes why build it instead of buy?
I am bias to solid wood and I would consider poplar or alder as a viable cheap hardwood besides pine. Using hardwood would save you all the face edges and would help in terms of nicks, dings, dents (kids will be kids). And, although it seems like a lot, I would actually try to show off the box joints by dovetailing all 4 corners. DVs would also be incredibly sturdy as compared w/ miters...consider the weight the books will add. All the forces involved and miters (end grain to end grain) become incredibly weak, regardless of splines/keys/locking. If you set up an "assembly" you can crank out DVs quick, besides being good practice.
Please understand that I am in no way trying to convince you not to build your project. I certainly hope that you do and I hope you understand my point. :)
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
Edited 2/23/2006 11:30 am by zombeerose
Edited 2/23/2006 11:31 am by zombeerose
Here's an alternative: let the plywood edges show. A lot of functional kids' furniture, even the solidly built, high end stuff has exposed plywood edges. Round them over and celebrate the visual interest of the plys. The design could be the top, bottom, and sides sitting proud of the front and back panels.
Well---it's an idea, anyway. ;-)
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