There are two types of epoxy used in club making: one is a slow cure that can take up to 24 hours to fully cure, and the other is the fast setting variety which takes as little as five to 10 minutes. It is easy to be drawn to the faster setting epoxy, with the temptation to try the club immediately, but it is better to use the slower setting where possible. Quick set epoxies are considerably more expensive and many don't have the shear strength to stand up to the wear and tear of a golf club. Also, the faster the epoxy sets, the less time the clubmaker has to assemble a club properly, let alone a full set.
Lethal weapon
Many years ago, while assembling a set of clubs for a European Tour player, I made a full set using a five-minute epoxy thinking I had enough time for the full 10 irons. It was only later that week, when the pro's playing partner at the PGA Championship at Wentworth was nearly killed by a flying wedge head, that I decided to revise my ideas on fast-cure epoxy.
Things have moved on a lot since those days, and in fact here at Golfsmith we occasionally use an epoxy that sets in literally seconds, as it works on oxygen starvation to cure. The tighter the fit the faster it cures, however on particularly snug fits we have struggled to align the logos before the shaft has set. The longer curing epoxy allows the clubmaker plenty of time to check specifications and make any necessary alterations.
Into the rough
Equally as important as the choice of epoxy is the preparation of both the shaft tip and clubhead hosel. If either is neglected, adhesion can fail. Firstly, the tip of the shaft must be properly prepared; for steel shafts this involves completely removing the chrome plating from the tip - the rougher the finish the better.
Using a one-inch belt sander with a 60 grit is the best method. A basic file is adequate but it is not as thorough and it is physically harder work. However, do not use a hard stone wheel on a bench grinder as this can gouge the shaft, leading to breakage and nullifying any warranty. It is important not to remove chrome above the top of the hosel as this will rust, especially on clubs that don't require a ferrule.
When preparing the tip of a graphite shaft, it is essential to remove all paint from the full depth of the bore. Failure to do so can lead to loose heads or that alarming "creaking" sound, which is caused by part of the shaft being fully secured while the higher torque of graphite forces unsecured parts to turn. The cheapest way to prepare graphite tips is to scrape with the edge of a sharp Stanley knife blade. This removes only the paint and it is virtually impossible to damage the graphite fibres. If you use a belt sander, I recommend you buy Trizac belts, which are designed specially for graphite and will not damage the shafts in the same way a sand grit belt will.
Examine the inside of the hosel to make sure there is no dirt, rust or anything else that might prevent the epoxy from adhering. Acetone cleans out any substance. Wire brushes or round files are a good idea to roughen up the inside of the hosel, and allow for a better bond between the epoxy, the shaft and the hosel.
Finishing touches
The last stage is to fit a ferrule, if required. The plastic ferrule is purely cosmetic, and its function is to hide the fact that the bore may not be central in the head. The ferrule should be slightly bigger than the hosel diameter, and if the bore is not central and the ferrule is an exact fit there will an over hang on one side, and the hosel will be visible on the other. Be careful when tapping on ferrules using the clubhead, as high repetition can cause joint problems, and more than once I've ended up having stitches in my hand after slipping! It is best to invest in a ferrule setter.
Once the shafts have been prepared, the ferrules fitted and any swingweight material added, it is time to epoxy it all together. Make sure there is an adequate covering of epoxy on both shaft and hosel, wipe any surplus off with paper towels, and remember it is easier to remove fresh epoxy than epoxy that has set. It is advisable to leave any gluing overnight, and to avoid any accidental contact with wet epoxy during day to day shop activity. It is advisable to leave any unused epoxy next to the clubs, so that you can check the following morning it has set properly.
By taking great care at this stage of the assembly, you reputation is in safe hands.
