Saloon Floor Support

[Phil Fontaine]

I followed with interest the exchange of information started by Dennis of
Miss Kathleen in October of last year as my boat had developed a similar sag
in the cabin sole. In my case a gap of about a half inch had opened between
the sole and the main cabin bunk face-boards at a distance of about 2.5 to 3
feet aft of the forward cabin bulkhead. So, I decided to tackle the problem
this spring before launching for the season.

Using the mast-step structure to support a couple of vertical supports under
the frame for the mast opening, as Dennis did, made a lot of sense and I
decided I would do the same. However, I was anxious to avoid getting into
the much larger project of cutting into the cabin sole, which it seemed to
me would be necessary to install supports at the half round stringers as he
did. Consequently I searched for a different approach.

From last October’s information exchange it wasn’t clear to me that all the
boats were built with the same number of vertical supports, though from
Dennis’s description it sounded as though Miss Kathleen and my boat were
similarly supported. In my case the first (going from forward to aft) p & s
vertical supports, which are through bolted to the crossbeams, are located
about three feet aft of the mast opening. It appears that Pearson depended
on the bending stiffness of the bunk face-boards for support of the forward
part of the main cabin sole and that support depended on wood screws through
a piece of wood attached to the back side of the face-boards into the
plywood sole. It was obvious that the sag was the result of the screws
having lost their grip over time.

My first thought was to try to replace the wood screws with through bolts,
but I found the task of getting access to the area behind the face boards
too difficult. I chose instead to install structural teak trim pieces (1″x
1½”) to the outside of the face-boards and then ran four ¼ inch bolts
through the trim pieces and the sole with fender washers and lock washers
underneath. I located the bolts on 12 inch centers beginning 12 inches from
the bulkhead. The attached photos show one of the two vertical supports on
the centerline and the starboard structural trim piece. I used a scissors
jack under the mast opening frame to remove the sag before installing the
new supports.

In the course of working on the sag problem I discovered that bolts in two
of the vertical supports on the port side, immediately aft of the area I was
working on had lost their retaining nuts and had backed out to the point
that they no longer engaged the cross beams. Fortunately the displacement
was only about 3/8″ before the sole contacted the end of the vertical
supports. The consequences of this, if any, were not noticeable. I was a bit
horrified to find that Pearson had used bolts that were too short to fully
engage the locking portion of the locknuts. Correcting this situation was
not an easy task. I’d be interested to know if anyone else has encountered a
similar problem.

Phil Fontaine
Aurora

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Original Message

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[Miss Kathleen]

Hi Phil,

Amazing similarity between our boats floor support. I will get some additional photo’s showing more of what I did.

Interestingly though, I jammed in some supports in the vicinity of the bunk sides only to find that they dislodged, impying that the floor “moves” when under sail.

I need to address the port side as there is some sag in that area. Another future project.

Cheers

Dennis

[Author]

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