Moisture, Tip Rust, and Failing Epoxy Joints

Written by Renata Villalobos · Bench Technician

The joint between a shaft tip and a hosel is a few square centimetres of epoxy holding together the two parts of a club that experience the highest forces. It is a good joint when it is made properly. It is not permanent.

Most joints fail at the interface rather than through the epoxy itself. The adhesive stays intact and lets go of the metal, usually because something got between the two.

The Three Things That Kill a Joint

Moisture

Water finds its way into the hosel gap around the ferrule, sits there, and works on the bond. Freeze cycling makes it worse by expanding whatever has collected. Clubs stored in unheated spaces over a Michigan winter get this treatment for four months a year.

Poor Preparation

Epoxy bonds to a clean, abraded surface. A shaft tip that was not properly sanded, or a hosel bore that still had old adhesive in it, produces a joint that was compromised from the day it was built. These fail within a couple of seasons and there is nothing the owner did wrong.

Shock Loading

Repeated fat shots into firm ground transmit an impulse straight through the joint. One is nothing. A winter of mat practice is a different matter, and it is another reason we look closely at clubs belonging to golfers who practise heavily indoors.

Signs That Show Up First

• A ferrule gap. A hairline dark line where the ferrule meets the hosel that was not there before. Often the earliest visible sign.
• A click at impact. A small metallic tick, usually only on solid strikes, that sounds like it is coming from the hosel rather than the face.
• Rotation under torque. Hold the head, twist the grip firmly. Any perceptible movement means the joint has already partly let go.
• Rust weeping from the ferrule. A faint orange trace at the ferrule line means water has been inside for a while and the tip is corroding.
• A ferrule that spins freely. The ferrule should be fixed. If it turns, the epoxy around it has gone.

What Tip Rust Looks Like From Our Side

We only see it during a shaft pull. Heat is applied, the head comes off, and the tip section either comes out clean or comes out with a band of corrosion where it sat inside the hosel. In advanced cases the steel has pitted, and that section of shaft cannot be reused.

Graphite does not corrode, but it has its own version of the problem: moisture works into the resin at the tip and the fibres delaminate. The visible sign is a slight swelling or softness right at the tip end. A delaminated graphite tip is finished.

The Fix

Pull the shaft, clean both surfaces properly, inspect the tip, and rebuild the joint with fresh epoxy and a new ferrule. Where the tip has corroded past reuse, the shaft is replaced. Either way the club goes back on the scales afterwards, because a rebuilt joint changes the swingweight slightly and we would rather correct it than let it drift.

Turnaround is two days. We use a long-cure epoxy deliberately, and rushing it would defeat the purpose of the repair.

Prevention, Briefly

• Dry the clubs before they go back in the bag after a wet round.
• Store the bag indoors in heated space over winter.
• Do not leave clubs standing in a wet bag for days.
• Check the ferrule line for gaps a couple of times a season.
• Have any club that clicks looked at rather than played through.

Joint inspection is part of every full bag audit and it costs nothing to ask for during a drop-off. It takes us about a minute per club.