A friend brought me a roller rod to fix for him. It is 5' 8" long, 50-80lb rod with no other information on it except for a tail-walking billfish. The rod was built as a 2 pc rod with a threaded sleeve and ferrule set up above the foregrip splitting the rod exactly in half. The sleeve looks to be SS but it rusted underneath and split the sleeve up to the threads. I have not seen a sleeve / ferrule set up like this before, not sure if I can replace it? Another option is to use a sleeve and make the rod 1 piece and the owner is good with that. I have a piece of aluminum tubing that will work perfectly but I am wondering if it will be strong enough? Or should I find something SS? I feel like either of these options will be stronger than a carbon sleeve considering the stress that will be put on this joint. I know that typically we would use an inner ferrule with an outer sleeve but the blank is solid glass. I have the ability to chuck the rod up in a lathe and drill each section for a ferrule if needed, what do y'all think?

Thank you,

Steve

Steve,
You have an iffy proposition at best, no matter what approach you take to accomplish it. That is why I would not trust a 2-piece rod for anything over 30lb and most likely why it is difficult to find multi-piece off-shore rods.
There are 2 main issues of concern whether installing a detachable ferrule or employing a “ferrule” (sleeve or spigot) to make the rod a 1-piece repair; and they kind-of contradict each other. 1.) The ferrule must be strong enough so that it will not break right where the two rods sections come together, and 2.) The ferrule must not be too strong / stiff so as to put undue stress on the blank right at the ends of the ferrule. In your case with a solid FG blank which is inherently quite tough, I would err on the side of making the ferrule strong enough to not break. You mentioned “I have a piece of aluminum tubing that will work perfectly but I am wondering if it will be strong enough? How can you be certain it is “perfect”? There are important considerations other than the physical size. Most of the aluminum sold at Home Depot type stores is 6063 (architectural) Al which is weak (20,000 PSI) but offers fairly good corrosion resistance. Multipurpose 6061 would be an improvement in strength (40,000 PSI) with OK corrosion resistance. The most common marine Al is 5052 (30,000 PSI) with excellent corrosion resistance. The common high strength Als are 2024 (50,000 PSI) and 7075 (75,000 PSI) but both have only fair corrosion resistance. All of the aluminums are very similar in mass weight, but stronger (higher PSI) alloys equate to being able to use a thinner wall.
If you do not know which alloy you have = don’t use it! Although I typically use 2024 or 7075, even in marine conditions, they are expensive, especially 7075, but to me it is worth it. As the name implies, multipurpose 6061 would be an acceptable compromise for your situation = decent strength and corrosion resistance. Since the tube would be bonded to the blank, when flexed under load, it will not be allowed to oval / flatten which is the beginning of failure. Nonetheless, .060in wall may be a bit too thin; I would look for a wall thickness of .080 - .090in. McMaster carr has one of the best selections of aluminum (tubing), alloys, diameters, wall thickness, length.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Can you adapt a trolling butt? Might lose some length, but an extension is possible as well.

What is the diameter of the female ferrule?

Couldn’t adapt a trolling “uni-butt without loosing too much length.
Not sure what the ferrule measured, it’s all gone.
Thanks for all that info Mark, ended up using some 6061.
Would still like to know about that original 2pc system that was on this rod, never seen that before.

Thank you, Steve