Thanks to those who provided their thoughts, especially our apparently
randy colleague at Sonoma products.
Tried it out Monday putting together some frames for shed doors. Just
joining some twobys, not jointed, planed or otherwise squared.
1. Amazingly clean. If I had routed those mortises I would have
shovelled up a bunch of chips even with the vac hooked up to the
router. With the Domino, almost no residue escaped.
2. Fast. 80 mortises took about 30 minutes after the locations were
3. Fairly accurate. I only had to open out 4 mortises to get a dry
fit, on all others the sanded tenons slipped right in. This despite
timber that was NOT "4 square".
At the bottoms of the door frames I was joining 2X4 stlies to a 2X6
rail. I used 3 10mm dominos on each side spaced across the 5 1/2
inches. Afterwards I realised that I could have cut overlapping Domino
mortises to create a 3 or 3 1/2 single hole, then cut a tenon from
pine to fit. More gluing surface, fewer interior shoulders, maybe
stronger in sheer due to solid long grain material in tenon. Hmm.
Probably overkill for this application.