|The warm weather is just around the
corner. And that gets me to thinking about outdoor projects, and the materials
used to build them, including dimension lumber ("two-by" stock).
Dimension lumber is a perfectly good material for outdoor and shop furniture
projects. But there are a couple things to consider when buying and working
with dimension lumber. Most dimension lumber is used for house framing --
joists, rafters, and studs. But when you choose dimension lumber for a
furniture project, it pays to sort through the boards more closely than a
building contractor might.
When sorting, I'm looking for the same things I look for in hardwood. Clear
boards with few knots and minimal warpage. I'll pick out the best boards I can
find (be sure to re-stack neatly) and then, as for other furniture projects,
buy a couple more boards than called for in the plans (to allow for waste when
cutting around knots and cracks).
After getting the wood back to the shop, there's the matter of moisture
content. Here in Iowa, dimension lumber is dried to a moisture content of about
20%. This is a higher moisture that I want when building furniture projects. I
prefer something around 12% or a little less. So I like to take the time to let
the wood dry out a bit more before making any cuts.
To dry the wood, just stack it in your shop for a week or two on a flat surface
with sticks between the boards to let the air circulate around them. If you
have a moisture meter, check the moisture content once in a while. If you don't
have a moisture meter, I suggest you give the wood an extra week to be safe.
As the wood dries, it may also change shape (warp, cup). Or develop checks
(cracks) on the surfaces or ends. So I look at the boards carefully as I begin
to lay out all the parts. When laying out the boards, I'm just marking the
rough sizes of the pieces in the cutting diagram or from the materials list
that came with the plans. Note: Give yourself about an extra 1/2" in width
and 1" in length. The main thing is to avoid any loose knots or cracks.
After laying out all the parts, I begin cutting the boards to rough size.
First, cross cut them to make the long boards more manageable. Then the pieces
can be ripped to rough dimensions. The important thing is to square up one edge
first. At this point, the wood may not have perfectly square, flat surfaces, so
the first edge may have to be jointed.
Shop Note: Also, if a board is cupped, place the cupped face down on the table
saw to keep it from rocking during the cut. Finally, because the dimension
lumber usually has milled (rounded over) edges, I make all the rip cuts with
the square edge against the fence. This way, when the piece is ripped to
finished width, the last cut leaves both edges of the workpiece square.
Go to Tip #49