Hi Everyone,
I’m building an oak plywood bookcase that is about 8″ deep, about 30″ high, and about 40″ across. I’ll be using an edge-banding bit to add solid-wood to the front of the shelves and walls. Unlike a taller bookcase, the top of this bookcase will be visible and usable, so I don’t want to put screws through it.
I have a couple of basic joinery questions.
Here’s what I know:
The walls have dadoes/rabbets. The shelves glue into the dadoes/rabbets. Screws go through the backing into the shelves and walls. Using corner blocks, I put screws through the bottom into the walls and bottom shelf. The edge banding adds rigidity to the shelves.
Here’s what I’m confused about:
Is glue inside the dadoes enough to give the shelves racking strength?
How do you give the bookcase racking strength on the top if you don’t want to put nails or screws through it?
I want to make sure these shelves can hold up to a full lineup of cookbooks!
Replies
Are you also ruling out using screws then covering them with oak plugs?
I've done some full height bookshelves from oak ply and used dados/rabbets then countersunk and screwed on top of that and inserted oak plugs in the holes.
I love the smell of sawdust in the morning.
I'm not really clear what you want to do from your description. But, if the bookcase has a solid back fitted into a rabbet that will prevent racking. Corner blocks are superfluous. I would be more concerned with the 40 inch span of the bookcase, particularly if you are using plywood for the shelves. You should check how much sag you will get.
1. Yes, the dadoes give plenty of strength to prevent racking, though the back is where the real rack prevention comes from.
2. If you want/need more strength glue a face frame to the front.
Thanks everyone for your help.Being new at this, I just needed to get some reassurance.
There's nothing wrong with a temptation to "over-engineer", LOL.
The suggestion above to take the span of your shelves into accound is a good one. Here's a link to help with that, the famous Sagulator:http://www.woodbin.com/calcs/sagulator.htmforestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
That's makes two of us. My name is pierre and I have always love to work with wood. I am going to need all the help I can get.
I think dadoes are unnecessary. Screws or even just 16 ga. brads, in combination with glue, are enough to hold the shelves to the sides. I have done this many times and loaded the shelves up with no trouble.
Racking, as others pointed out, is prevented by the back panel. Again, I think dadoing this is unnecessary, but it becomes an aesthetic consideration if the edge will be visible. I use door skins for back panels and brad them into place. Just make certain the panel is perfectly square!
You can prevent sag on those 40" shelves by making the solid wood edging on the fronts wider, say around 1-1/2". You are already planning to pin the shelves to the back panel, which helps a lot.
"Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
I just looked at your web page.. Nice stuff.. I like it...
I had a 'Travelling Thrones' but my outhouse got washed off the hill! LOL...
Thanks!I had a travelling throne for a while too, had to move it every so often when the pit filled up... eventually got that newfangled indoor-plumbing thing, once we got over the idea of doing THAT inside the house it wasn't too bad!"Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
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