I have gotten a few questions (actually 3) from folk about to how create the Incra Double Dovetails Joints such as the one in this project:
I will not be making a box in this blog. But a really good friend saw this box and asked if I could make a 14” x 19” serving tray in the same style. Maureen has been a huge help to my wife and I so I was happy to get a chance to make something for her.
Obviously, first place to start is to get an Incra Jig System. I have the old 16” LS positioning system with an upgraded Wonder Fence. The positioning system is awesome. The wonder fence is a “nice to have” and is expensive ($170 + an upgrade of original fence extrusion $40) and I still have mixed feelings about it being worth it. Mark, the incra tech support guy, was empowered to knock down the cost of the replacement extrusion $10 and was very helpful, so thumbs up for Incra support.
One important thing I have found with the Incra joints is make sure you have a zero clearance insert around bit or it tends to yank the workpiece sideways and downwards when the bit contacts which giives sloppy joints. I just use a piece of 1/8” masonite held in place by the router table.
Step 1 – Creating laminations for tray sides
Prepped the raw stock by face jointing the stock, then edge jointing it.
The planed it to a consistent thickness (7/8”)
I used an incra marking gauge to mark the cut line carefully to ensure that the width of the maple + 2 paduak strips would result in neat 1/2 pins on each side. Ripped to width on table saw.
The incra system comes with a template book with full size drawing that lets you figure out precisely how to size the stock so that you can space joints properly.
It is important to have stock that is square and true. Jig gives accuracy to 1/1000” so stock that wobbles is not going to make nice, tight joints.
Cut strips to rough size for glue up
Glue up using bar clamps. Need to watch for strips wandering around a little when you clamp. For next project, I might make the paduak strips a little wider than the maple strips
Since I travel a lot, I use old hotel card keys as a glue spreader:
Then hand planed laminations down to the final size (3/32”)
I use my table saw fence and a clamped stop as an impromptu shooting board for final clean up.
Again, the incra template guide will give you a suggested stock thickness for a given pattern, so in this case, they are suggesting I use 1/2” stock. So I used my bandsaw to cut resaw the laminations.
Used planer to take them down to final thickness.
Use Radial Arm Saw to cut to final length
This a lot of work for 4 sides:
Next Steps – Cutting the joints
-- Shawn, I ask in order to learn