Some of this stuff is redundant to the "Wrinkles" and "Half Template" articles.
Setting the bow is made easier since the process making a template lent hints of things to come. The bow is now sprung into the fixture, pre-fitted and at the ready. The sail is either squeegeed or taped to the working surface and the spine has been installed. Reinforcements in the way of leading edge tape, nose/tail tape, battens, folds or whatever are applied also. Lay the bow down on the sail temporarily to check (again) for fit. Remove. Cool.
Dab a glob of contact rubber cement (artists quality) on the wing tips of the sail with an acid brush and spread. Only about 1" square inch. Dab a glob at either end of the bow also. Bout' 1" from the tips up. While the cement is still wet, set the bow and position. I get that warm fuzzy feeling when the bow aligns perfectly to the shoulders and the wingtips of the sail. Almost as much as when I was a teenager and Collette LaBlanc pulled her blouse up over my head! Ooo la la. Not quite but almost. She was ab-so-lutely ravishing. (That one goes out to you Pappy)
Now don't touch that mother till the cement dries... When dry, gently push the bowtips into the wingtips of the sail with a tool or sum'um' - for better adhesion. Its just kind of tacked down temporarily. Now we make the incisions. I don't know about your kite sail but mine has about 3/8ths of and inch seam material along the outside curve of the bow from shoulders to tips. Near the tips the seam widens to a long triangular shape. Eventually this extra material will be folded, glued and taped over the bow. Take a look at the back of an Indian kite - you'll see what I mean. Um, now we make the incisions. All we're going to do is make a small tab at the end each wingtip to begin containment of the bow. The slice will be located 3/8ths of and inch from the tip. I like to use a curved X-acto blade. I start at the out side of the bow and stick the point of the blade down into the seam. Then rotate the blade to the edge of the seam to make the slice. If you drag slice vise rotate slice, yer' on yer' own. Might tear the sail.
OK. Roll the tab halfway over the bowtip. Slip a plastic pallet knife beneath the tab and gently stroke back and forth slowly increasing the angle of the knife. Umm, both sides. This will insure adhesion. Before you tuck in the tab nice and neat, remove the jig.
This is a pregnant moment laden with many a fork in the road. If that damn bow boinks out'a there Mad Mary will get angry enough to spit, YER' gonna' hate it - and pretty little Collette? Well, if yer' a woman she'll scratch your eyes out. If you are a man she'll make you cry......... Anyway, Use the knife to finish the job, quick. Burnish the tab with best seal possible. Good and tight. Try and not get any chunks a' debris on the cemented parts of the wingtip that are still visible. That's some nice work my friend. Trim tapes that run from sail to work surface. Remove and handle with care. Now go ahead and admire it for awhile.