I'm building a guitar speaker cabinet that measures 15" wide, 27" tall, and 22" deep, with airtight construction and 3/4" thick walls. The front panel will have a 1/2" inset and angling back about 15° at the top. I have a bunch of clear rough-sawn 2x6 Douglas fir that I bought wet from the mill back in 2020 and have let dry in my shop since then. My question is whether I should just square the edges for glue-up or if I need to use dowel pins, tongue and groove, or biscuits for the joints when making these panels? The wood grain will be exposed, but I'm concerned about the cabinet's durability, especially when I crank up the volume. Any suggestions would be greatly appreciated, particularly regarding anything I might have overlooked.
1 Answer
As long as your Douglas fir is properly dried (and being four years should be enough), you should be fine with just using glue, provided your boards are squared and the surfaces are flat. Dowels and biscuits help with alignment, but just gluing long grain to long grain is usually strong enough. You really need those extra reinforcements for cross-grain or end grain joints though.
Totally agree! I've heard that long grain glue joints can actually be stronger than the wood itself. I get your concern about vibrations affecting the cabinet, but if you're keeping the long edges flat and adding dowels in the corners, I think you'll be solid!