I build giant tuna rods using aftco ferrules and short bent butts. None of my rods have ever broke but recently heard of several that broke at the ferrule. I was asked how this could have happened? My first response was either builder error or faulty blank. I have been giving it more thought and now I think that it is most likely builder error. I now think that the metal ferrule creates a shear point. My builds typically have a gap between the blank and the ferrule which I always fill with another piece of blank to fill that gap. I think that it is very important to fill the gap fully to make sure that there is no space between the blank and the metal ferrule. You need to completely fill that gap completely with some kind of material be it a piece of blank/ masking tape and epoxy so that there will not be any possibility of contact of the blank with that metal edge of the ferrule. There is so much bend in the blank that it can otherwise make contact with the edge of the metal ferrule and cut into the blank. I wonder if anyone else has run into this situation too? These are heavy blanks with lots of wall thickness where it is attached to the metal ferrule. I believe that this also happens where metal reel seats are used on heavy rods.

I have only built a few rods for tuna and I always made a spigot to fit in the end of the blank the length of the ferrule depth aside from filling the void between the blank and ferrule wall in my humble opinion it keeps the blank from going from round to an oval shape which could cause the blank to fail at the ferrule

The best day to be alive is always tomorrow !!
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Wi.

When you overload any blank on any rod I've seen, they all break right above the reel, or right above the foregrip on some designs, don't see where you have a problem. No rod is indestructible, it failed where it's supposed to.

The video that i saw where the rod broke was only with 35 lbs of drag on a blank that normally we fish upwards to 65 lbs of drag. The fish weighed 350 lbs whereas we have landed giants over 900 lbs with no problem. The only difference was that this was being fished on the gunnel whereas we only fish standup with pad and harness. The rod was not in a high stick position as the fish was out from the boat. Does not make sense.

If the rod was fished on the gunnel, did the blank get nicked? The other thought was that the blank was able to move in the ferrule...

No the rod was facing the water and is stiff enough that it cannot hit the gunnel.I can only guess that it was properly glued and would not move in the ferrule. It was not my build and I was asked for my opinion by the distributor.
I am not sure about the breaks usually occuring right at the reel or foregrip. Is this common? I assume that that the most common place would be where the blank bends the most. which in this case would be about half way to the tip.

Just a thought Mel. What about the guide placement? Is the guide placement(spacing) different from your rods? Maybe the location of guides in relation to the ferrule is putting an additional load on ferrule causing it to fail. My $.02.

There is indeed a stress point at the end of the metal butt ferrule. However, the parts and pieces are designed with this knowledge and have been built to withstand this stress, including the blank being against that metal edge you speak of. Sometimes a builder will cut and install a blank into a uni-butt that was not designed to be used in such a butt. The walls are too thin, etc., and breakage at the edge of the ferrule is the result. You have to careful what blank you install a uni-butt on - not all were specifically made with that use in mind.

In the case where you have a blank that was designed to be used in such a butt, any breakage is usually traced to a defect, or a reduction in diameter of the blank by the builder to make it fit into the butt. It is always better to shim up, than sand down. You need to maintain a certain wall thickness at the junction with the ferrule.

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The blank is 6 ft long. It is necessary to cut from the butt about 12 inches to fit into the unibutt to maintain its 6 ft long length. I have cut over a dozen of these blanks in the past few years and the wall thickness is the same at the end of the butt and at where I cut. A uncut blank will not fit a #2 ferrule but any cut from 6 inches up will require a shim so no sanding would every be required. The only sanding that I do is to fit the graphite tubing that I use as a shim and never sand the blank itself. But the failures have not been on any rod that I built and i do not know how the broken one was assembled. I am just curious why it would break at the ferrule and this has been reported to me on other builds with other blanks as well. The blanks that I use were not designed to be built with a unibutt but was designed to be built with a through blank handle.

My builds are all spiral wrapped and the broken rod was spiral wrapped as well although I do not have any information about guide placement. In the 12 rods that I have built, I have had zero broken. In fact a couple rods have caught over 20 giant tunas on it ranging up to 800 + lbs.

Mel,
Don't get hung up on it. Likely a latent defect in the blank.
You obviously know how to build rods since you have several that are just fine.

Stuff happen.

Move on and enjoy the fruits of your labor.

Be safe

"The blanks that I use were not designed to be built with a unibutt but was designed to be built with a through blank handle."

Mel, You may have answered your own question with that statement. It's possible to get lucky with blanks that were not designed to be used in a uni-butt. Maybe most of the time, but it's equally possible to have a failure, or many, depending on whether the blank has the design attributes to make it suitable for use in a uni-butt.

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Thanks everyone. And yes, lots of wall thickness where I cut.

But apparently not enough for use in a uni-butt.

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No Tom, I am not the one that had a failure. Mine have never broken at the ferrule nor anywhere else. I feel confident that my builds are strong.

Unless you actually see the broken rods do not believe it. Although I would agree with Tom that you cannot take just any blank and mount it in a UniButt and think you are OK. Not all blanks are made to work with those ferrules, cut or full length.