While building a set of stairs recently, I noticed that a crack had developed in the bottom of one of the vertical-grain fir stringers. Because they were exposed on both sides, I wanted to glue and screw the crack closed, but I had difficulty filling the crack with glue.
A co-worker’s shop vac helped out. As shown in the drawing, I poured a little puddle of glue over the top of the crack and applied suction from below. A piece of tape over the end of the crack prevented air from being drawn from the side of the crack. I ran the vacuum until glue began to show up across the bottom of the stringer. It took about 30 seconds to fill a 4-in. crack.
Gregory Coffin, Loveland, CO