mast repair, hull deck joint and boom kicker

[mikestevens]

It has been a while since I last posted. I am the person who was looking for mast splicing info. in short, the outcome is as follows;
I did find someone else who had a bent mast in MI who I am hoping will sell me his old mast for splicing. It has been really hard to find an old offshore 6040 spar. A lot of close but no cigars. I also plan to have it professionally done. We spoke a lot about tapped screws in this forum, but I have seen plug welded splices on new masts (for the new Navy 44's) In one instance the suggested direction was to use rivets, and in another it was the plug welding? Any thoughts on those solutions?

while I am sorting out the rig issue, I have begun to fix some pesky deck issues, not the least of which is a leak that originates at the hull deck joint and comes into my electrical panel and ends up collecting in my battery box. I have removed the toe rail and the rub rail to expose the deck hull joint.
I have found an area that I think was repaired before and corresponds to the leak streaks inside the boat. there is a section in which the bedding compound between the hull and the deck seems to be not cured. I can rub it and it will smear in between my fingers. A small area (less than 1/4" in of the core in the deck is rotted out. It does happen to be near the diesel fill tube. Perhaps the compound used is degraded by spillage?
Should I use thickened epoxy or 5200, or something else here?

Also I have drilled out the holes in the deck (mostly under the jib track) and have removed the bad core. On a few of the holes the bad core went back about 1.5", for a total of 3" or so. Can I use thickened epoxy here, or should I cut out the area from below and replace the core? I hate to do this because it means taking out the fabric in the quarter berth.

Lastly, I have a rigid boom vang on my boat. If I remember correctly, these caused booms to break in a bad seaway on a particular Bermuda trip. I have seen images of the "boomkicker". this seems to be a much more boom friendly device. any imput?.