Mast Step - Cutout?

[ebb]

Roy.
Just took a look at my original maststep and it IS exactly like yours.
That fore-and-aft slot is where the square tenons go.
The 1/8" mortised cross is on the bottom side of the step.

Been a long time since I decommissioned A-338. Looking at the
maststep here makes me think differently about that cross mortice,
which as you show, and what I have here, is NOT to receive the
mast base casting in any way. I was entirely very wrong.

First of all, The mortise is athwart the boat, port and starboard.
And the indentation is only about 1/8" deep. (On my step the router
bit has left a telltale of slight circles in the wood. Meaning, it was
intentially placed there for a reason.)
And it's definitely on the underside of the step.

OK. Obviously it housed a piece of metal. A plate was anchored in
place by the two #20 bronze screws that went through the step
and cabintop and into the oak strongback. It probably had a
larger hole in the center into which a wire conduit tube was fitted.

And since we know there originally was a piece of pipe conduit there,
extending up into the mast to fair lead internal mast wire below -- I'd
guess the 8 to 10" (guessing) conduit probably screwed into the plate
to keep it erect. Remember various photos showing this piece,
always cockeyed or bent. Which could happen if the plate was
threaded... hardly any thread in 1/8' plate thickness.
The 'sump' created there by the mast base casting collects any water
trapped in the mast, funnels it thru the step, leaking around the plate
into the composite and into the strongback below.*

Given some of Pearson's 'wham-bam-thankyoumam' solutions I've
run into... that plate should have been bronze to survive the airless
environment under the step next to those bronze lag screws. But it
probably was 304 and probably corroded and disintegrated in far
less time than five decades it's been hidden under there.
Imco, nobody would restore this original design, running wire below
thru the mast. Causes too much trouble..

So that would solve the mystery, imco.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*Fresh water leaking thru the mahogany/phenolic plywood maststep,
not only will eventually compromise the step but also rot the balsa
composite core in the deck below it. The hole for the wire was left
unprotected in the original installation. Some of us fixed it by partially
routing out the cabin top under the step and replacing the 'tunafish'
with solid fiberglass.
Some have also replaced the wood step with aluminum or G-10.
By the by, the rotting of the balsa and the pressure and weight of
the rig, also flattens the curve in the cabintop -- as well as influences
the plywood that makes up part of the strongback and bulkhead.
Which see.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Opinion. You know how a stick in water looks bent?
..............That's why I never take a bath.

[roythomas]

Yay!!

I was thinking there is no structural reason to replicate the original step and had similar concerns about proper water drainage you just mentioned. I may route a little groove on the bottom to allow water to escape without pooling in the step. Thank you for investigating. Now I can't decide if the step is a consumable because of eventual deterioration and therefore ok to varnish and replace every 5 years or should I try to fabricate something permanent and epoxy/fair it in. I'll go with consumable for now. It's and easy "make" as far as I can see. My boats previous owner already rerouted the electrical to a separate fitting on deck next to the mast. Sadly he never epoxied the drill holes and I now have rot in that location (among others because of his half baked installs).