On Aug 21, 10:52 am, "Morris Dovey" wrote:
eganders wrote:

| Has any one tried an approach to stabilize the edge fibers of the
| cut edge? It would appear that might hold the most promise from the
| superglue result so far.

I've had good results routing both edges straight, flat and square and
joining with epoxy only. I cleaned up very carefully with a sanding
block - and there was no trace of joints after painting.

Might work for you, too. FWIW, I don't like butt joints in MDF and
normally do a M&T-type joint.

A rabbet with a mini-mitre works well. (DO get that image of a bunny
with a pope's hat out of your mind NOW)
Porous-to-porous MDF joints can be very strong if one uses an adhesive
with sufficient capillary action to take advantage of MDF's weakness.
I have built bass boxes with 4x18" woofers which stood the test of
time and drunk roadies for many years.
A butt joint to the shiny side of MDF is only as strong as the first
layer of surface-tensioned dust....not good.