On 12/30/2013 5:24 PM, -MIKE- wrote:
On 12/30/13, 1:33 PM, Digger wrote:
There are special edging bits for routers that can be used to enhance
glue-up of stock trim ...i.e...

https://www.routerbits.com/plywood-edge-banding/whiteside-edge-banding-router-bit-set/

The cutters ensure sufficient gluing surface for a very strong bond
between case and edging.


The inherent flaw in those bits is that it is way too easy for the
pointed edge of the hardwood to split open the plywood when clamping.

If one chooses to use an edge banding router bit, it's much better to
use a bit that has a flat section, so it can't wedge open the plywood.

After trying router bits for banding, I came to the conclusion that
their best purpose is to provide income to the people who manufacture
and sell them. :-)

A simple rabbeted banding that is thicker than the plywood is as strong
or stronger than these special profiles and much easier to do. Plus it
give the added advantage of making the front profile thicker, which
looks better in most applications.
http://mikedrums.com/shelf_edge_top.jpg
http://mikedrums.com/shelf_edge_bot.jpg


Agreed.

The point was simply that there are bits of many flavors, as in the
example indicated (i.e.), that can be used with a router to increase the
surface area for glue up and add strength to the joint. The added
advantage of course is that the trim interlocks with the casing and thus
keeps the edging centered while curing.

Your rabbited method is excellent and the normally preferred
alternative, assuming one is not looking for edging that is flush on
both faces. Simplicity + added strength is indeed the primary goal and
the rabbit also assures accurate alignment. However, in a curved
applique it may also be considerably more difficult, if not impossible,
to apply to a contoured edge. But then, in extreme situations, banding
with tongue and groove method would not work either.

Whenever possible, for fully flushed edges, I personally prefer biscuits
above all, but in many situations the edge band is entirely to thin to
support this method.

So, in essence, the method used is largely dictated by design, tools
available, and desired outcome. This only goes to show that once again,
there is indeed more than one way to skin the proverbial cat ...uh oh,
cat lovers everywhere will now hound me to death!

Speaking from my own experience though, I've never had an occasion where
casing walls blew-out or split while clamping tongue & groove, but that
is only my own experience. Most of what I build these days is fairly
limited to simple hardshell cases for instruments & audio road gear,
wherein the rabbited method would certainly not be appropriate.

Good reply Mike,

--

Digger
Bob O'Dell