Plywood as Tenon

[Birdhunter]

I want to try using Baltic birch plywood as a sliding tenon in 3/4" quarter sawn white oak. I've seen the technique on YouTube. The guy made the slots using a 700 Domino. The mortise on one side is about 2" wide and just fits a rectangular piece of plywood. The mortise on the other side is about 1/2" wider than the plywood. The "just fits" plywood is glued in. The other end floats on the "too wide" slot.

What would be the best bit size and plywood thickness combination for 3/4" oak?

 

[Naildrivingman]

The 1/3 ratio is what the domino connection is based on, so applying that in connecting 3/4" stock the domino thickness would be 1/4" and the cutter would be 6mm, but the tenon will be sloppy.  You may have to use 3/8" and sand them down a little.  You might get lucky since domestic plywood is nominal and the rated thickness is generally greater than the actual thickness, so 1/4" and 5mm cutter might be a good fit as well as 3/8" with 8mm.

Personally, I use 8mm dominos for 3/4" assemblies.

 

[Birdhunter]

The 8mm and 3/8 sounds worth a test cut.

 

[Cheese]

FWIW...Woodcraft sells Baltic Birch in metric thicknesses.
https://www.woodcraft.com/categories/plywood

 

[peter halle]

Just as a side note - I believe it would be extremely hard to find true imperial sized thickness sheet goods here in the US - no matter how they are labelled.  Metric has been at work for ages.  With a caliper you will find that the imperial labelled goods are closer to metric than the advertised.

Peter

 

[leakyroof]

Just as a side note - I believe it would be extremely hard to find true imperial sized thickness sheet goods here in the US - no matter how they are labelled.  Metric has been at work for ages.  With a caliper you will find that the imperial labelled goods are closer to metric than the advertised.

Peter

It's a conspiracy..... [wink]  Metric infiltrators... [wink] [wink]

 

[Paul G]

Just as a side note - I believe it would be extremely hard to find true imperial sized thickness sheet goods here in the US - no matter how they are labelled.  Metric has been at work for ages.  With a caliper you will find that the imperial labelled goods are closer to metric than the advertised.

Peter

I've heard Appleply is accurate, but have yet to check it personally

 

[GravyBones]

You might want to think about using a slot cutter router bit and and cut a slot with a router. Lower the bit just a tad and make another pass until you get the slot width you looking for exactly. Sneak up on the perfect thickness for your plywood tenon thickness.  I,have a slot cutter bit that cuts 1/4" and I use it for much thicker 8/4 and 12/4 slabs that need 1/3 thickness slots so I make a few passes until I get the thickness of the slot I'm after. By the way I use a hardwood tenon I cut on the cabinet saw though. Plywood might be too brittle. Are you trying to make a breadboard end or something that float with moisture content changes?

 

[Birdhunter]

After 5 not good enough tries, I have come up with a great technique for a sliding pinned tenon using my Domino. If I knew how to post photos, I could share the technique.