DIYbanter - View Single Post

wrote:
I'm building a bookcase with four fixed shelves (plus the top). It
will be a total of 50" high and 30" wide.

Go play with the Sagulator (google) before building any bookshelves
more than 2' wide.

The shelves will be sliding "half-dovetails."

Even simple dados would be adequate. If you're routing these dovetails,
then a full dovetail is probably easier to cut. Don't be afraid of
getting an accurate fitting joint here - it's one of the easier parts
to get right.

The bookcase is being built out of flatsawn cherry (YOU try finding
rift/quarter-sawn!),

Actually I have no trouble (although cherry is itself scarce in the
UK). It's a high-end timber, so it's one of the few where there is an
obvious trade in quarter-sawn.

and the sides will be a total of 12" wide.

Now this starts to worry me. I think your shelf plan is sound, but a
big slab side like this might need some care in design and
construction.

1. Because the wood is flatsawn, the grain patterns are harder to
match-up,

Actually figure, rather than grain. Grain's the little stuff, figure's
the big "cathedral" patterns you see on a flat sawn board.

so I would like to glue-up two 6" boards, rather than three
4" boards.

For the shelves, then stop worrying. Assemble 4" boards because they're
easier. On a loaded bookshelf you'll never see the difference. 6"
boards sound quite reasonable for the sides though.

am I setting myself up for problems with cupping/etc?

Depends more on the quality of your timber than on the size difference
to 6". Personally I'd already have had this board in stack for a year
or two before I got round to using it. I'd certainly store it at
ambinet use humidity for a few months before planing it (you do have
some $5 air hygrometers, don't you?)

I am NOT gluing the dovetails,

Up to you. It's no problem to glue them because it's not a
cross-grained joint. Personally I wouldn't even pin them - friction is
plenty adequate. Just pinning at the front would be the right thing to
do though, if you did pin them.

Any relative movement in the timber is going to be cupping, not
shrinkage (if these boards are all the same timber from the same
batch). I'd worry about cupping in the sides, but not the shelves.

Personally I'd be concerned about the sides in this design. I'd want
something to support the sides against cupping, particulary if they're
6" wide and relatively thin. This could be framing top and bottom,
full-blown frame and panel, or a sliding dovetailed batten on the
inside. Most of all though I'd just want those sides to be well-dried
before I planed them, and not too thin.