LumberJocks Woodworking Forum banner

Newbie: making a solid oak bookcase out of Menards oak. Wood expansion? Plywood?

3K views 7 replies 7 participants last post by  ppg677 
#1 · (Edited by Moderator)
I was thinking of a basic 36"x60"x11" bookcase out of all Menards solid oak. I am thinking of just making a box (box joints…I just ordered a Dado blade for my table saw) and then cutting dados for the shelves. Not sure about legs- perhaps just a small apron/leg arrangement with mortise/tenon joints and then pocket screw that into the bottom of the main box.

Yes, I know that paying $3-4 per board foot of Menards shrink wrap oak is perhaps 2x higher, but I don't own a planer yet and I've made a couple nice smaller items out of this stuff that looks really nice.

One concern I have is that it seems most bookcases for sale, even those advertised as "solid oak", seem to use plywood for some of the construction (like shelves). My only thought is that I'm not yet carefully considering wood expansion.

My understanding is that with these planks, a 36×11" shelf is going to perhaps expand and shrink in the 11" direction up to an inch (tangential to the grain which is 8% expansion?). No problem with the dados. In the radial direction, there is 4% expansion possibility so I believe this means the 3/4" thick wood could expand 1/32" of an inch. Should be no problem with the dado I hope. And I think the 36" part of the length won't expand at all. Now I could be misinterpreting grain direction…yeah, I'm looking at pictures but still a bit challenging for a wood newbie.

If my interpretation is correct, any other reason not to use solid oak for the entire construction of this bookshelf?
 
See less See more
#2 ·
If the wood is dry, say 8-14% moisture. It will not change much once its built into your house with heating and cooling. Also, the expansion would be ok since all pieces would expand the same. With that being said, i wouldn't build it with solid oak. To me its a waste of money when i can make it look just as nice with oak ply and solid oak pieces as edges.
 
#3 ·
You're way overestimating the shrinkage and expansion - the total shrinkage of red oak is 8% as the wood dried from green to oven dried (ie as dry as you can get it). The wood you're buying was kiln dried, it may have taken on some moisture since, but if you calculate shrinkage from 15% (an extreme annual maximum) to 7-8% you're only going to get 1/4 inch shrinkage.
But like Bill says, it doesn't really matter - on a bookcase the shelves and uprights all have the wood grain running in the same direction. The only way you could run into problems would be to glue horizontal boards on the back.
 
#5 ·
I don't know if you can read this well, but here are the stats on red oak shrinkage.
Font Parallel Paper Paper product Document


The gravity is on the left and the shrinkage is the right column, but the above comments are correct in that building the casework correctly with corresponding grain direction will make seasonal wood movement a moot point. I have built several bookcases from solid wood and many from ply material, my preference being solid, but that is just me. I got lucky a few years back and got white oak, poplar, cherry and walnut for $.15 per BF. I bought about 1,000 BF of each. Haven't used much of it yet, but I am hoping to soon. It is all about 5/4 and would work good for bookcases. O.K. I am rambling, have fun on your case.
 

Attachments

#6 ·
Here's the thing with bookcases… If you make the sides from solid oak panels, then make any fixed shelves from solid oak as well. If you make the sides with a frame and panel style, then make any fixed shelves from plywood. Although a solid wood panel will move within its frame, the outside dimensions of the frame won't change.

Whereas a 12-13" solid oak panel side will move about 1/4" with seasonal changes. This assumes red oak and 6-12% moisture range. Ie: if you moved it in an unheated basement for half the year, it would move 1/4" at most. 1/8" is more realistic in a heated / air conditioned home.
 
#7 ·
If you are fussy at all make sure you check the thickness of each board you get. I was building some cabinet doors from Menards oak, (maybe all retailers are the same?) but the thickness varied maybe a 32nd of an inch and maybe a little more. Certain applications aren't that fussy but it threw me for a loop one time, until I got a planer.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top