Trevor, I recently overhauled my 30 year old refractors, the grease in both had hardened and was useless. Now with telescopes, they are going to be used in all extremes of climate. So I went to the experts and asked Don at Bintel what he used. He recommended Superlube, a high quality grease that won't bind your moving parts or melt in the heat.
It made every movement silky smooth. John
