hi rehd,

not that the other methods don't work, but i wonder if you could do a no-brainer hybrid scarf/butt joint that wouldn't take a lot if skill to accomplish and yet get the thinness of the scarf w/ relative ease of a butt.

the idea would be to turn the 2 panels upside down so the back is exposed and butt them up against each other near (not necessarily on) the edge of the bench and clamp them in this position(from the edge or over the top w/ short scraps screwed into the bench and over the top on ea side) leaving say 3in free on ea side of the touching panels. then sand into this area w/ a grinder going the 12xthickness sanded thru ea way. sand sort of a dish or concave shaped depression stopping on the join as soon as the lowest(face veneer is reached).

then lay in subseqently smaller layers of epoxy and glass, let set up and sand flushish.

then you get an equivalent of a scarf joint, a thick face veneer, a fairly easily uncompromised line where the 2 match.

I like this ideas as you could overlap the ply before laying out the panels and double cut the ply on any complex pattern or curvature or slant, dish this whatever join line and still get the equivalent of the thinner less awkward(storage and moving around) scarf joint but with none of the hassles of trying to carefully scarf the face veneer.

i'm not saying the other methods don't work fine, but that this might be another interesting way that would open up other directions

-mick