I think Beardking had it reversed - let it stay for 24 hours to cure then you have the most strength. 30 minute epoxy "sets" in 30 minutes - the point where the epoxy has taken it's final form and is no longer workable, but it's not done drying yet.

On ARFs - if the joining rib sides already have a glaze on them (i.e. they have a shiny appearance) then you should sand that off. The epoxy will adhere to bare wood much better than a coated surface.

I also like to poke tiny little holes in each surface with a T-pin. These hole don't go all the way, but just enough to make a little pit. I think this gives the epoxy a little more grab as it can fill the tiny holes. Make sure you put a coat of epooxy on each side and use a popsicle stick to put a little pressure on the epoxy coat to make sure it gets in good.

On my Avistar and SkyVista - I sanded off the glaze, poked a bunch of little holes in the sides to be glued, then epoxied them. I used a combo of masking tape and some clamps to hold it in place and left it over night.

I completely trust that joint. I beat the snot of my Avistar with high G stuff (outside loops, snaps, etc.) and it's held up great. Knock on wood!