: Ok, I warned you I'd be posting a few dunce like questions.

: I've decided to go for the ply strongback (for the ES); 16 feet is a *long*
: bit of 4x2 especially if I expect it to remain straightish for 6 months in
: a garage of fluctuatinng humidity.

: 1. I buy a full sheet of half inch thick plywood (8 feet by 4 feet)
: 2. I cut it on a sawbench into strips 8 feet long and either 2 or 4 inches
: wide.
: 3. Here's the problem: I need to cut 'corner off' along the long side of some
: of the strips. The pic below attempts to illustrate: +++++++++++++++++
: +
: ++++ P L Y W O O D : 0.5"
: ###+
: ###+++++++++++++++

: The bits marked # have to be removed. How? Is that what a router is for? Is a
: hand router good enough? etc etc.

: 4. Then I go on to glue it together into a v. long box; a sort of coffin for
: a boa constrictor.

: Regards,

: Francis.
My guess is that you want to cut the rabbet to provide a bigger glue area between the strips.
If this is the case,why bother to cut the rabbet at all? Just screaw and glue another thin scrap strip inside the rabbet. This provide a better / stronger support than a thin out thin-to-begin with 1/2" ply.
Sort of like
xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xoo oox
xoo oox Where x stands for the 1/2" ply you cut already
x x o stands for whatever scrap lying around
x x your shop that can be cut to fit
. .
. .
x x
xoo oox
xoo oox
xxxxxxxxxxxxxxxxxxxxxxxxxxxxx