Once a golf club shaft has been broken, it cannot be repaired, but it can easily be replaced. Shafts can be replaced at golf pro shops and most golf stores, but it is also a fairly easy project to do yourself. Replacing your own shaft can save time and money, and allow you to try a new shaft without purchasing new clubs.
Insert the broken shaft into the vise and remove the shaft by using the heat gun to warm up the hosel and loosen the adhesive that holds the shaft in place. Use medium heat for graphite shafts and higher heat for steel shafts. Once the adhesive has started to melt, pull the broken shaft from the hosel, which is where the shaft meets the club head.
Apply solvent, such as lighter fluid, to the rag and wipe away any leftover adhesive from the inside of the hosel.
Measure the new shaft and mark it at the desired length. Wrap masking tape around the area that will be cut and then place a marking on the tape. Use the hacksaw to cut down the shaft.
With the shaft still in the vise, use sandpaper to rough up the tip of the shaft, which will be inserted into the hosel. Graphite shafts may have coating on the end that should be removed with a sharp blade before sanding.
Apply epoxy to the inside of the hosel. Make sure the inside of the hosel is completely coated, then coat the tip of the shaft with epoxy. Slide the shaft into the hosel and turn the shaft so that the club head is properly aligned to the shaft. If there is a ferrule (small plastic piece), it should be inserted into the hosel first, then coat the interior with epoxy and slide the shaft in.
Remove the shaft from the vise and tap the butt end of the shaft on the floor to make sure it has been completely inserted into the shaft. After using solvent to remove any epoxy that has leaked, stand the club up and let it dry for at least 12 hours.