Plywood cabinet carcass construction

[Adam Slutsky]

I'm building 10 cabinets for a wall unit (5 base and 5 bookshelves on top) out of birch plywood with poplar face frames and doors. The cabinets wil all be painted. No outsides will show since it will cover a complete wall. I'm planning on screwing and glueing and biscuting the carcasses togethers. Not sure what the best way of putting the back on. Should I put the cabinets together and then route a rabbit or run the boards along the router table and then put the cabinets together. Or should I just nail and glue right onto the back? I'm just getting back into woodworking after a 20 year hiatus and appreciate any advice I can get!

Adam

[glenn bradley]

The assemble, route and drop in method that you describe is what I frequently do.

[Anthony Anderson]

Adam, Assuming this is going to be a built in and will not be removed. If I were doing this, I would not use biscuits. Tack the sides with a finish nailer or stapler, then screws and glue are plenty strong enough. As far as putting the backs on, I would glue around the perimeter and tack on the backs with 1/4" x 1.25-1.5" staples or finish nailer, and then use 1.5" #6 screws about 4" apart to permantly fasten after that. This is fast, and with glue, is really strong. Don't forget to square carcasses before installing and fastening the back. Keep in mind that you will not see the screw and staples after everything is attached and installed. If these are not built in, then I would use different joinery methods. Just my opinion though. Post pics after you are done. BTW, Welcome to SMC, if anyone hasn't said it yet. Good Luck, Bill

[Adam Slutsky]

You will not see the backs or sides since they are all built-ins. I like the ease of just putting the backs on with nails/glue/screws and saving a step. What would you recommend for the back thickness? I have not bought the plywood for the back but was thinking of that beadboard looking plywood. Not sure how that will finish but I'm assuming that it is made to be painted.

[frank shic]

adam, i generally use 1/4" for the backs and use suspension brackets to hang the cabinet to the wall. you can use a nailing strip in front of the back to mount it to the wall or if you want to get real fancy, you can even use a french cleat. staple and screws is one of the fastest methods of putting together a box!

[Adam Slutsky]

Frank, what is a french cleat and what is a suspension bracket? I was planning up ripping a piece of wood with a 60 deg angle with one part on the wall and one part on the back of the cabinet. I could also screw it directly to the wall.

Thanks for all of this input - this forum is fantastic!

[Anthony Anderson]

Adam, What you described is a French Cleat system. Those are very handy if you want a system that you can move around in the future as your needs change, and are very handy in a workshop as you can move them around quickly and easily. But if the units you describe are not going to be moved, then you will really not gain anything, and additionally the thickness of the wall cleats will eat up available wall/cabinet depth. Personally I would use 1/2" plywood for the backs. Let the plywood extend beyond the top of the unit 3/4" and then cut a piece of wood/plywood that is 3/4" thickness, 2.5" wide x the length of your cabinet. Attach it using glue and screws (make sure they don't go through the top) lay it flat against the top of the cabinet, butting one edge against the 1/2" plywood back that is extended beyond the top. Drill ~30degree angled holes where the wall studs are going to be. Use#10x3"-3.5" screws to attach units to walls. Simple and strong and will not be seen once the units are in place. Also, I use "Spax" brand screws. These screws have a serrated edge that doesn't split or splinter wood. A little more exspensive, but well worth it IMO. Bill

I was planning up ripping a piece of wood with a 60 deg angle with one part on the wall and one part on the back of the cabinet. I could also screw it directly to the wall.

[Adam Slutsky]

1/2" thickness plywood sounds good and strong to me. I'm not quite sure of your attachment description. It sounds like you are making some sort of wood cleat but I don't get how the 1/2" and 3/4" material line up. How about just letting the backs extend up beyond the top of my top cabinets and screwing through the plywood? That area will be covered with mouldings and will not be visible.

[frank shic]

adam, what you described with ripping a 60 degree piece of wood and using the other piece as a mating mounting rail is basically a french cleat. just make sure that you cut the openings in the cabinet sides so that the rail will be able to pass through.

a suspension bracket is a piece of hardware that attaches to the cabinet sides and has an adjustable metal clip on the back which locks on to a metal mounting rail. here's a link to check out:

http://www.true32.com/ProductDetail....0000-968813117

[Adam Slutsky]

Frank, thanks, the top cabinets will be resting on the bases so they just have to be held to the wall. The load will be on the base cabinets. Maybe just screwing to the wall toward the top is the best option. I'm Not sure how to fasten the top book cases to the bottom cabinets. Would biscuits be a good solution for that? Or maybe they don't need to be fastened together???

[Roland Chung]

Adam,

You mentioned faceframe construction. Is there room, on the bottom of the upper cabinets, to install blocking? If so, carefully measure and drill through the top of the base cabinets (countertop) and run screws from below into the blocks on the uppers. It might help a little, if the walls are bowed, to keep a gap from showing up as you screw the upper to the wall.

[Jim Becker]

I typically just tack the back on the carcass with narrow crown staples...which is just fine for 1/4" material. When it needs to be thicker material I put rebates on the carcass edges before assembly to accommodate the backs.

[Adam Slutsky]

Roland: My top bookcase sides will rest on top of the bottom cabinets. There would be no room for cleats. I'm probably not describing this properly. Top cabinets will be open bookcases and the bottom will be closed with doors. The bottom cabinets will be 15-18" deep while the bookcases will only be 12" deep. The top bookcases will simply sit on a finished "counter" set on the base cabinets.

Jim: I assume by rebates, you mean a rabbet.

[Jim Becker]

Jim: I assume by rebates, you mean a rabbet.

Indeed. Both terms are correct.

[Roland Chung]

Adam,

I can picture what you are describing. I am curious, is there a faceframe on the front of the uppers? Is the lower "rail" of that faceframe about 1-1/2" or 2" high? Is the top surface of the bottom panel, of the uppers, flush with the top of that lower rail? When the upper cabinet sits on top of the base cabinet, is there a hollow space under the bottom, between the faceframe, sides and back?

See how hard this is to do without pictures?