GUYS !
Scarf joints are EASY!. I read on other sites that 8:1 or even 12:1 were optimal. Lemme tell ya. 6:1 is just dandy. I need to reorder my order of operations. I split the plank into thirds on my bandsaw. THEN sanded the finish off the biggest thirds and split it down. I was trying to get three pieces out of each plank but it's not practical unless verging on paper thin is ok.
Still two planks ber board is great with a skinny left over for accents and stuff.
I used scrap to make a scarf jig for the router. it works great but I wish my router plate was clear plexiglass. I can't see what I'm doing.
After making the scarfing jig I realized I need to make a gluing jig. So off to that I went. Kinda like a bench hook. Glued it up with TB3 and let it sit overnight. I then ran the whole thing through my lam sander affectionately named "knuckle rubber". TO think I almost made it by sandwiching a bunch of those mini skill saw blades. Fortunately i played that out in my head and saw the possibilities.
With all that sanding to clean up saw marks and glue joint and flipping it and basically holding it by one end out flat.. the joints held and are invisible. If I bought this lam I'd think... "some lucky guy has a source for 74 3/4" bamboo planks. Bastard. But wait! It's meeeeeee!.
New process: Clean finish off with router set to 1/16" depth. Saw out planks. Sand on lam grinder. Scarf. Glue up. Clean up joint on lam grinder. DUN! move on to building bow. Lam grinding time minimized.