Spigot joint on the Sneaky Pete let me down in a big way. Not going there again unless absolutely necessary.

The only other choice is an overlap joint. Being in the butt section of the rod, I need the strength, so am using a piece of graphite composite blank. Aside from the measurement and checking taper (which has gone without a hitch), before I cut and glue, how much overlap should I allow on what will become the female ferrule, in order to keep the strength?

Actually, you need to use fiberglass for any oversleeve. Using graphite that is larger in diameter than the rod itself means the stiffness of the sleeve will be much greater than that of the rod. Aside from the problems with continuity of action, other problems with sheer stress can come into play.

Ralph's article on rod repair in the online library here has all the specs you need per overlap and material requirements.

Normally I shoot for an overlap length that is roughly 8 times the diameter at that point. Less than a factor of 6 is not enough, more than 10 is more than you need.

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Thanks Tom. It's quite soft graphite/fibreglass composite from a cheaper rod. That rod was so soft for it's action, I think it was mis-labelled! No other fibreglass scrap lying around, plus I'm now back on the other side of the world.

The butt section is only 16 inches long, with two upper sections both about 30 inches long once everything is done up. I thought the spigot material I had would have been strong enough, but once I taped on the guides and did the static stress distribution, it bent rather awkwardly. The dry fit over lap seems fine so far.

I guess it has more graphite in it than it seems. The dry fit joint is quite stiff. Also, the wall thickness is frightening? 1.5 millimetres is huge!

The section is 3 1/2 inches long, and has an internal diameter taper of 7 to 8 millimetres. Anybody got matching fiberglass scrap with wall thickness of about a millimetre?