Best results are obtained by pouring spinnerbait and buzzbait molds with a ladle. A bottom pour melter may not have enough flow volume to fill the cavity before the lead cools. This results in partially filled cavities and wrinkled heads. The wire shaft often gets in the way of the melter nozzle causing difficulty in getting lead into the cavity. It is very important to use soft lead when pouring spinnerbait heads.
Every major fish hook manufacturer produces hooks especially for spinnerbaits. Make sure the hook you select has a small eye. Large eyes tend to block the flow of lead into the cavity and result in incompletely formed heads. Some choices are the Mustad 32606N and the Eagle Claw L253.
Our preformed spinnerbait wires have a small bend to attach the hook. Crimping the bend closed makes it easier to load and position it in the mold. Diagonal cutters work well for us.
It is common to have difficulty getting the skirt collar on the head to fill completely. The problem is caused by the hook eye blocking the collar. Try this tip: After the mold is closed on the inserts, look into the cavity gate and make sure the shaft/hook eye connection is centered in the body of the head. It can slip down and block the collar making it impossible for the collar to fill. After the inserts are in position, we bend the wire shaft a little bit to hold the hook and shaft in place while pouring.