Good News on the Keel Bolts

I got a drawing of the keel and keel bolt layout from Tartan which Paul forwarded to Jim Taylor.  He then got the data he needed to run through an American Bureau of Shipping (ABS) keel bolt routine that is an industry standard which Jim has been using for decades.  The result of this calculation gave a minimum base bolt diameter of exactly 0.50”...the size of the smallest bolts that are used on Owl Moon.  The bottom line from Jim is that that "the bolt diameters and locations do appear to be adequate to take the expected keel loads" (of course, that should have been the findings as the Tartan 4300 is CE approved for category “A” unlimited offshore).

Jim recommended the following keel installation and attachment steps:

 

- Carefully checking the condition of each keel bolt for cracks, pitting, etc.

- Cleaning and leveling both the top of the lead and the bottom of the keel sump.

- Developing a good mate between these two surfaces by ‘buttering’ both surfaces with wet epoxy, and dropping the hull down onto the keel with a release agent between the two, and allowing the epoxy to cure.

- The hull would then be lifted off the keel again, the two surfaces ‘buttered’ this time with a thin layer of 5200, and the hull again lowered back in place for long enough to allow the 5200 to cure fully.

- All of the keel bolts should be fitted with sizeable SS (or G-10) backing plates, not just simple washers.  The bottom edges of these plates should be radiused (softened) so they don’t cut into the glass. These plates should also be ‘potted’ in epoxy so that there are no voids underneath, and so that the load is spread evenly over the plate.

- The bolts should be properly torqued, according to their diameters.

This is more or less the steps that Paul had previously discussed with us.