The bow ring on my Mac 21 is loose. How can I tighten it? There is no access to the nuts holding it from inside the hull.
The inner liner at the bow covers the part you need to get at. You will need to cut an access hole through the inner liner and then make yourself a nice cover (from wood?) to put over it after you are finished.
I believe most of the bow ring's were supported in behind the glass with a piece of wood and then they just put washers on the back side of the U bolt to hold it in. Before you end up pulling the U bolt through the glass, cut yourself a hole and take the U bolt out and put a backing plate on it.
I cut a heavy gauge 2" pipe about a foot long in half lengthwise on my bandsaw and then drilled holes in it for the U bolt. I put the U bolt back in the original holes, then through the "half=pipe" backing plate and tightened it all up. The glass is very thick at the bow, so now with the pipe as a backing plate, my bow eye is VERY strong.
I just had a look and I guess I don't have pictures, but if my explanation isn't clear enough and you would like I can take some and share.