The world’s strongest ferrules were not on fishing rods, but rather they began as constructions on spacecrafts.
From Space to Multi-Piece Fishing Rods
These spacecraft ferrules are graphite composite tubes epoxied into metal fittings, and the situation is very similar to mounting rod blanks into butt ferrules.
The earliest spacecraft application of graphite composites was the use of real fishing rod blanks in making flexible antennas some years ago. These days, however, the spacecraft engineers use specially-made graphite composite tubes of various sizes as their structural members, but it’s all based on evolution from fishing rod technology.
This saves weight by replacing metal structural parts with lighter graphite composite tubes of equal strength, just as rod technology has saved weight by progressing from steel rods and tubes to today’s strong lightweight blanks. The spacecraft tubes must be bonded into metal fittings to permit subsequent bolting the assembly to the rest of the structure.
The Science Behind Ferrules and Epoxy Bonds
So, the fittings serve as ferrules, and the bonding is done by adhesives which are very similar to those used in rod building.
In fact, a laboratory pull test was done and the results demonstrate that the epoxy bond of tube to ferrule is stronger than the tube itself since the tube broke first. The straight tensile pull got up to 12 tons before the tube fractured; and the epoxy bond held firmly.
For reference, the tube under test was only one inch in diameter with a wall thickness of roughly 1/16 inch, roughly the size of an offshore trolling rod butt.
In this test and other similar studies, preparing the surfaces for epoxy is a significant consideration for the best bond. The key is to use an isopropyl alcohol and clean the area as much as possible.
If you don’t clean up the ferrule before bonding, it may not work. This scenario is one of the leading problems that can result in failure.
The Epoxy Products Rod Builder’s Trust
In the market of rod building, one of the most popular lines of epoxy comes from ProProducts.
Proprietary blends of two-part epoxies, each product is designed by expert rod builders for extreme ease in application and the ultimate bond in the fishing rod.
Produced as an epoxy finish for guide wraps, rod decals, and more, ProKöte is an excellent option in your rod building workshop.
Available in a standard thread finish and a high-build thread finish, both ProKöte products create crystal clear seals over guide wraps and rod decals. These finishes work great as a seal, but are also championed for maintaining the flexibility to work with the rod rather than against it.
ProPaste is the leader for strong bonds with fishing grips, handles, and reel seats.
When mounting a rod component on the handle assembly, ProPaste is the most trusted and widely recognized epoxy paste in rod building.
ProGlü takes the bond strength of ProPaste and puts it in a form of flowing glue that is easier to get into tight spaces and great for quick fixes.