Oversize rollers were therefore turned in seasoned oak, the natural tannin in the oak increasing the durability of the rollers, but this itself created a problem in that the tannin would corrode the steel pin that ran through the middle of them. Men’s Shed expert wood turner, David, came up with an ingenious solution, sleeving the oak rollers with bushes made of an exotic hardwood, Iroko, which would not cause corrosion of the steel.