Pearson 365 Mast Step

[ZULU40]

My Pearson has the standard issue problem for a 365, the steel mast step on the keel and bottom end of the mast are quite corroded.

While a new stainless steel step is in route and the mast has had its bottom 2" clipped; my problem is that removing the old step required that whatever was left of the nuts securing the plate to the keel had to be ground away. What remains of the threaded stumps is barely thicker than the steel step to sit on them.

Just how then to secure the step?

[TreblePlink]

Do the bolts go to the lead keel, or are just bedded in fiberglass? I would expect that most of the load would be compression, and the bolts are in shear to prevent lateral movement.

Depending upon the thickness of the new base, you may be able to machine circular recesses into the new plate so you have a bit more thread to work with. If there's thick glass under it, you might be able to add some lag screws.

[ZULU40]

Originally Posted by TreblePlink

Do the bolts go to the lead keel, or are just bedded in fiberglass? I would expect that most of the load would be compression, and the bolts are in shear to prevent lateral movement.

Depending upon the thickness of the new base, you may be able to machine circular recesses into the new plate so you have a bit more thread to work with. If there's thick glass under it, you might be able to add some lag screws.

Indeed the plate is slotted fore and aft to provide some adjustment, but I do not know what the studs are held by. The best hypothesis I can offer is that they're held captive within the enclosed lead keel, but I don't know this for a fact ...

[sailor_ed]

I would run a small drill down into the keel and see what I brought up. If lead or solid glass then lag bolts would seem in order. If you run into a large void then we have something to ponder:-) I am working on the assumption this is an encapsulated keel.

Be sure to seal things well in this area as it is a possible water entry point to the keel.

[ZULU40]

Originally Posted by sailor_ed

I would run a small drill down into the keel and see what I brought up. If lead or solid glass then lag bolts would seem in order. If you run into a large void then we have something to ponder:-) I am working on the assumption this is an encapsulated keel.

Be sure to seal things well in this area as it is a possible water entry point to the keel.

Yes its encapsulated lead

Yeah an exploratory hole only to be done when I cook a batch of epoxy next, so it can be resealed right away if it all goes awry. The drawings released look like this one below, but the boat seems flatter at the mast to me, after all it was square on the bottom so it would be logical that the step is square to it.

Mines a ketch just like this, cutters has about a foot more aft location for the mast.

[jpendoley]

You might post your question over at Pearson365.com Lots of discussion about the mast step work arounds there.
Jim

[ZULU40]

just thought I post the solution we came up with

we made a new step out of stainless steel

SS being roughly twice the strength of mild steel means the replacement can be much thinner, so the base plate of the new step is just 6mm thick. This allows that the studs are now able to be threaded for a fastener that will have enough grip.

Here the studs are run off with a 7/16" NC button die that will take a conventional nut and washer on the forward pair, but may have to make some special custom nut for the aft pair as the grip is still a tad too shallow. Envisage doing this out of scrap SS plate.

My thanks for people helping to find a solution.

[dieseldan]

If the mast step bolts are lag screws the might be able to back unscrewed with a stud remover socket wrench. They are available in different bolt sizes.

https://www.sears.com/search=craftsman%20stud%20remover