Another darn gap question…

[Bruce Page]

How much gap, if any, would you leave between the end of the tenon and the bottom of the mortise? I would like to keep the gap minimal – would the glue (Titebond) squeeze out without a gap? e.g., the fit was 1/1?

[Jamie Buxton]

One trick you can do is to make the gap zero (or nearly so) where you can see it, but larger back inside the joint. The larger gap provides space for any excess glue.

[Jim Becker]

Since that's a tenon visible on the end, I really wouldn't leave any "gap" outside of normal snug, but not "tight" fitting. But even if it's not, the only real reason to have a "little space" at the bottom of a mortise is to provide a little room for the glue that gets pushed ahead of the tenon as you mate the parts...and that doesn't need to be a whole lot. If your tenon is fitted well, a thin, even coat of glue is more than enough. There really shouldn't be a whole lot of extra glue.

[Bruce Page]

Thanks guys, that's what I needed to know.

[Reg Mitchell]

Hi bruce...i have seen fery small groves cut with a pocket knife along the tenon to allow the glut to squeez out nulifyeing the pressure when pushing the tenon into the mortise. I thinnk I read smewhere 1/16 of an inch should be left at the bottom. Also I cut the tenon at the base against the sholder about a 1/32 deeper than the tenone it self so any soueez out will collect it the shallow grove
Reg

[Dave Anderson NH]

Hi Bruce, My approach is to take the end of the tenon and put a 45 degree chamfer on all 4 sides. This allows plenty of space for excess glue at the bottom of the blind mortise. I also put glue only on the inside walls of the mosrtise, none on the tenon. This prevents any squeeze out from creeping out onto exposed areas of wood. As for your original question, I usually make the tenon .062" shorter than the mortise depth.

[Jim Becker]

Dave, that's a great idea...and fast. A quick swipe of a sharp tool on the corners you want to knock off is all it would take. I'll have to use that one next time!

[Bruce Page]

That is a good idea Dave. I'll put the champher on all the edges that don't show. Good tip on just wetting the inside of the mortise, I've been worried about squeeze out. This joint will also have two square pegs so it should be strong.

[Roger Wilson]

I'll second chamfering the ends of the tenon and the edges of the mortise.

Another thing you can do is just glue three quarters of the tenon, no glue on the shoulders. This will provide plenty of strength and limit any squeeze out.