Hi Jay,

It all depends on the accuracy you want. Aluminum extrusions aren't
usually all that straight. As an example, I just walked out to the
shop and compared two 12 foot lengths of 6" x 3/4" by butting edges
together. There's a gap between the two that is, at it's widest point,
about 1/16". I've seen 1/4" or more gap in the past. You can expect
to do better on a table saw. If you can get a wide piece like this
(the 3/4" thickness isn't significant, 3/8" would be fine) and have an
edge milled (a shop with a large gantry mill) then you could probably
use it for some pretty accurate work. At 16', it will still be pretty
hefty, you might want them to mill out some of the interior while
they're at it.

Ed Bennett

http://www.ts-aligner.com

Jay Pique wrote:
Hey, anyone got a suggestion for a 16 foot long straightedge? I'd like
to be able to use it for template routing, rather than jointing, the
edges of long panels and boards. I'm thinking an aluminum extrusion
would be the way to go.
JP