StephenM wrote:
With finger joints, it's not about the bit, it's about the jig.

With finger joints it's at least as much about the bit as the jig. A
dovetail you can adjust by changing the depth. With a finger joint bit and
a jig either the bit's the right diameter or it isn't. It might be possible
to design a jig that allows the spacing to be altered easily by 1/100s of an
inch but I've never seen one.

Might actually be interesting to design.


Building a well-adjusted BJ jig is very fussy. The alternative is
using a DT jig with a BJ template (you might as well buy the stock).

What's a "BJ" in this context?

I have had good luck end-joining painted exterior trim with but joint,
biscuit joined and water-resitant glue. Over a hal-dozed years the
latex paint has kept a continuous skin over the joint.

If you have access to a buiscuit joiner, I'd go that way, otherwise a
more traditional scarf.

A BJ is labor intensive if you're not set up for it and it would look
just plain weird when it telegraphed through the paint.


For the curious, I'm replacing some of the trim boards on my house
that have rotted at the end(s) because no caulk was applied when
installed 15 years ago

I'll take end-priming before caulk any day,

-Steve