Improving access to deck fitting bolts on a 1985 Mac 25

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Improving access to deck fitting bolts on a 1985 Mac 25

Post by Seadoc » Tue Feb 05, 2019 11:36 am

Does anyone out there in Mac land know of a way to secure the nuts for deck fitting bolts in such a way that the bolt can be removed and/or tightened from above without requiring someone below decks to prevent the nut from turning. (This applies especially to those under the cockpit coaming.) I'm in the process of replacing my deck hardware and hope that one of you may have figured this out. What I'm wondering is there something like a carriage bolt arrangement. An idea I have is that a nut might be fixed via epoxy or some other glue to the underside of a fiberglass or wood backing plate which is itself epoxied inside the boat under the fitting.

Any merit to this or am I just hopelessly trying to beat boat designers at their own game?

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Re: Improving access to deck fitting bolts on a 1985 Mac 25

Post by topcat0399 » Thu Feb 07, 2019 6:34 am

With thru bolts that are sealed to keep water out.....

I don't know how that can be done if the bolt head and fitting on the outside has sealant on it,
you have to keep that fastener still and tighten from below, other wise it will leak.

I know from much experience that improper bedding of deck fasteners can bring on big problems.
Not only can water come into the boat but can get in between the fiberglass layers and rot the deck cores.

Pot the holes, countersink, use appropriate sealant (I use butyl), and tighten the nuts from below while being held from movement above. There is no other good way in my opinion.

Bite the bullet and do it right or pay the consequences later....

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