"Pat Barber" wrote in message
...
Don't try to get to the thickness of the plywood.

Cut a rabbet to a "known" thickness(1/2" is good)
and then route a slot using a 1/2" bit.

Using this method, you can really get very close
and not worry about weird sized plywood.

Actually, I would make my dado and sneak up with
the rabbet.

You can do this with a table saw or a router table.


Thank you Pat. I have been watching this same question for a long time now,
and have wondered why people make so much of such a simple thing. Measure
what you have on hand - cut to fit that measurement - glue it up. Good
Lord - why does it have to be so complicated?

--

-Mike-