gday , hoping I am not a twit but I can't tighten my new Colin mc Phillip center fin on my allwave . Thought I would be clever after weeks of searching and reading and save myself some dollars getting these from eBay side fins fit like a glove but the center just won't tighten any help would be great as I have been hanging to get out on these new fins . Cheers K

Hi Krist
sounds like the thread has been striped .on the nut
you may have to change the nut or bolt ...usually the nut strips

it easy enough to do ,striped one myself ,in a hurry.
Got anymore board you can borrow out of.?

naah--ive got the same problem with my 8'11" aw

got a new finset and the sides fit well, but the center, even if torqued fully (cleared no stripped threads) shifts up/down about 1 or 2 mm's at the screw end of the fin--annoying, given the big cost of the sweet fcs finset, but seems to have no effect on the h20

Try just putting on a few strips of tape cut to fit the bottom of the base of the fin. Aftermarket fin manufacturers often seem to make their fins a touch small. I think its because the tolerances for long board fin boxes are so lax.

Could be the screw (bolt) is too long and is bottoming out on the bottom of the fin box before the fin is secured properly....

Try filing the screw a few mm shorter being careful not to damage the threads. Don't keep tightening or you may crack or punch through the fin box insert!

Paul