Well...I've passed the point of no return.
--the mast is cut down, the old one-holed tang has been removed
--I've pre-fit the comptip to the mast...took a little shaping and sanding...I "snuck" up on it in order to get a tight fit
--I've inserted the foam plug to a depth of 12 inches
--the comptip inserts to a depth of 6 inches (leaving 6" for foam)
--I drilled a hole at 9 inches down from cut to fill with foam (not done yet) and plug
The next step is to glue the stainless plate (it's in the shape of a cross section of mast) against the foam plug with plenty of marine silicone?? The spray foam will fill the void between the plug and the inserted comptip. What would happen if I put ping-pong balls in that 6" airspace, glued up the comptip, and then foamed through the hole allowing the foam to fill around the balls? Would I have created a space of added boyancy to the mast ...or at least a permanent section impervious to leakage with the added benefit of boyancy?? I'm guessing the answer is: "follow the directions...they don't call for ping-pong balls, just spray foam". It seems like trapping an air-tight object inside the to-be-foamed 6" void would encourage more mast floatation. Is it a silly idea??
My Aussie style halyard comes with a small stainless halyard "keeper" (fairlead?) for which there are no layout numbers or instalation instructions. Does this small keeper just perswade the halyard from getting hung up on the battens? I was all set to install it about 3 feet below the yet to be installed tang...it looks like that in the illustration. At the last second, I felt bad putting 2 more holes/rivets in a space that may be airtight already. Do I really need to install that little halyard keeper?? If so, it seems like placing it on the side would direct the halyard out of the way of the battens as apposed to installing it on the front of the mast like the illustration showed.
Also, is my jib halyard cheek block, on the bottom of the mast, rendered unnessessary by the Aussie style jib halyard??
Thanks all you commenters for the input...I want to do this right the first time! bones.