Keel Bolt Anchor Repair

[Terry Phillips]

If you're going to the trouble of making fasteners, I would reccommend using
a 5/16" or 3/8" "Stub Acme thread" which would hold up to repeated use much better than a standard V thread.

Dimensions for 5/16" x 14 pitch, stub acme thread.

External thread - Major Dia .3125" , Minor dia .2597" , Pitch dia .2871"
Internal thread                    .3225                   .2696"                  .2911"

[Zach Freeborn]

On the mk.2, the keel bolts into a plastic plate that is in turn screwed to the deck as opposed to the threaded sleeve in the deck on the mk. 3 deck.  To install the t-nut, all you have to do is enlrge the holes in the plate to fit the nut, there is no fiberglass work involved.

I would replace it with a T-nut from your local hardware store instead of ordering any fasteners from the UK.

We have had some major issues on jackpot, an incident in Charleston on some rock pile with a big sign on it, and in miami on one of the reefs trying to sail in and out of the harbor. We had something similar the t-nut from the factory. Hull #119. The problem isn't the t-nut or similar products its the strength of the area you embed it into. having guides put in will help if you hit stuff and bulking up that back area where the keel bolt goes in. We cut the shelf out that was there, it was 3/8" thick, and epoxied a piece of stainless steel with a drilled and tapped hole. It was an easier fix for me since i'm better at working with steel than fiberglass/gelcoat.

[Robert Bernard]

What's the verdict on using T-nuts to replace the big head bolts? Has anyone dome this? My keel bolts are shot and my plate no longer screws down to the hull anymore with the forward 2 screws. I'm trying to think of solid ways to fix this, but I keep coming back to the blind G10 method. There has to be something easier...