Repairing a light spin rod, and have had to cut the blank and make a new ferrule. I am using a fibreglass oversleeve, and I am confident about how to go about it, but I just thought I'd get some more info first.

So what is the minimum sleeve length I can use? On a rod this light I am thinking in the 3 inch range. I have several pieces of f'glass that'll fit. Just wondering, don't want the worst to happen 'cos I didn't allow enough overlap.

I am anything but an expert in the world of repair, Ted, but 3" is the max I would go and you could probably get away with 2" or even a hair less. Are you making an actual ferrule or are you splicing?

Thanks Mick. I am making a ferrule. One of the pieces I have is 2.5 inches, and fits the area perfectly (dry fitted). Seeing as the ferrules on production rods routinely go 2 inches plus (seating depth), I have always kept mine to slightly less than 2 inches. This gives me about 3 and a bit inches for the overall length of the sleeve I am using. I am hoping a shorter piece on very light rods would not create any huge stresses. It just looks a little cleaner than a 3.5 ich or even 4 inch piece.

2.5 sounds pretty good for a ferrule, especially if your definition of a light spin rod is the same as mine. Anything larger I think would just make a flat spot.

Cheers for that Mick. The rod is a 2-6 lb spin rod. Originally 1 piece, broken fairly close to the middle. I've extended it just like I did my Loomis SJ6400, and ended up with 2 almost equal sections.

If you have the artitcle in Rodmaker that showed how to make these repairs and new ferrules, there was also a formula for figuring out the correct length of the sleeve. I don't have it in front of me but if you have that issue it's in there. It might also be in the article on rod repair in the online library on this website.

Ted,
It sounds to me like what you are planning is about right. If you are worried about the stresses that the ferrule will create they are going to be more a function of the difference in the stiffness of the rod and the ferrule. A stiff area in a rod created by a ferrule results in what is called stress concentration just in front of the stiff area. How much stress is a function of how large the difference in stiffness is between the rod and the ferrule. The larger the difference in stiffness the higher the stress will be.
The reason that fiberglas makes a good ferrule for a graphite rod is that the ferrule will naturally be larger in diameter than the graphite blank and the larger diameter would tend to make it stiffer but the glass has a lower modulus (stiffness) than graphite. A graphite ferrule would result in a much stiffer ferrule and higher stress.

Thanks guys.