I was just gifted my father’s sunfish, took it out and while the boat is fabulous, the main sheet, while “like new” seemed to hold water and did not flow through the block as smoothly as I remembered. Also, was tough on my hands and I have never had to wear sailing gloves in the past. I don’t know the thickness of the sheet but saw that on SunfishDirect that theirs is 10mm, and on Ebay there is a Sunfish “racing upgrade” sheet that is 8mm. Suggestions?