I wanted to make my tips removable so that I could adjust balance after painting with washers on a bolt / nutplate within the tip...

I cut my lead counterweight back about 1/16" with a router bit in my dremel, rounded the corners, taped the aluminum then sprayed the lead with PVA. I also tapered the ends of the fiberglass tip...

I then glassed over the lead and back onto the fiberglass and trimmed and sanded the new counterweight cover once cured. They came out pretty good...

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Glad to see I am at the same spot on my project. I have the same question. I was considering just coating the lead with epoxy and blending with the outside of the wingtip.