Re: P15 improvements

Bernard Johnson (
Tue, 04 May 1999 17:57:55 -0700

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West Wight Potter Website at URL
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> My '87 has a thin layer of foam between the liner and hull sides already. Are
> you sure your later boat doesn't have the same? Exercise caution when using
> pour in foam in closed places, it can generate enough pressure (heat too) to
> break things

I didn't realize that this may be the case. I will check!

> Good-bye table?

I don't think what passed for a table will be much of a loss. I am thinking along
the lines of using the hatch boards spanning the cockpit seats.....

> >
> > 4. The keel raise and lower system to be accessible in the cockpit
> > (without having to remove the hatch boards). Said system to incorporate
> > a positive lowering arrangement capable of opening a jackknifed keel
> > against gravity in the case of a turtle.
> Let me know when you figure out a good way to do this. Harry is always
> clandestinely raising his centerboard (it's in the cockpit on a P-14) on the
> downwind legs and trying to sneak that lateen rig by me (successfully, all
> too often). I need a counter-measure.

I believe this should quite easily done. I propose to use (initially) the same
pulley arrangement as exists for raising the keel. I will duplicate it except in
reverse. Leading the lines out into the cockpit can be done in a number of ways.
I am contemplating drilling two holes below the bottom of the hatch opening, and
leading the lines out through a suitable (nylon?) grommet. The lines would then
be restrained by use of small cam cleats.

> > 7. Provide a jib downhaul operable from the cockpit.
> Fitting a jib downhaul costs less than $15 and is one of the wiser things a
> P-15 owner can do. Your experience has amptly demonstrated the lack of
> stability a P-15 has when a single-hander goes onto the foredeck.

I wouldn't dream of going out on the foredeck any time the boat is not moored to
the launching ramp!

> > 8. Buy a new mast with a much stronger cross section.
> A heavier mast may not be what you want to prevent a capsize. Adding weight
> with a fifteen foot lever arm over the boat will work against the limited
> ability of the centerboard to right the boat.

I agree, but that is not the purpose of the stronger mast. The reason I mentioned
this is that many times (in really terrible conditions of course), the mast gets
broken. I'm thinking of the account of the Potter sailor who had his mast broken
on the way to Hawaii, also Robin ???? in "Dove". I don't ever plan on being in
those kind of conditions so it isn't important to me....just a thought! I have
just today found a source for mast extrusions, one of the stock is the P15 mast
($8 per foot). The next size up is the same cross section, but scaled a bit
bigger ($11 per foot). The weight per foot is also given, along with the second
moments of area, allowing a good comparison. I don't know what the total weight
difference may be for say 15 feet, but bear in mind that the moment arm will
probably be closer to 10 feet ( 1/2 mast + height of step above center of
buoyancy). When you run the numbers it is remarkable how little righting moment
is supplied by the keel, thus my comment about not having too much faith in it!

> > 12. Provide some kind of floatation at top of mast to discourage a
> > turtle. (The method used on catamarans).
> The Capri 14.2s used for sailing lessons and rentals at a nearby lake have
> white plastic "bulbs" with a vague attempt at streamlining attached to the
> tops of the masts. Is this the kind of thing you are suggesting?

I vaguely remember seeing this kind of thing on catamarans (which makes a lot of
sense given their low ultimate stability), and I must confess it would look a bit
stupid, however, the floatation force would be applied at a most effective moment
arm, say about 18 feet. There is a company that makes triangular shaped slip
covers, filled with floatation material, that slip over the head of the main, in
effect becoming part of the sail. This would look a little better....

> > 13. Install a heavy duty pump.
> Where? Would this be a hand operated pump or an electric?

I think it best to be human powered. I suspect the battery and/or wiring might be
in bad shape in the conditions leading up to a swamping. Incidentally, a sealed
gel battery or similar should be used . Remember Robin Knox-Johnson getting
battery acid spilled in the flooded cabin? Chlorine gas?

> > 16. Take along spare clothes, towels, in a waterproof container.
> What about just keeping a change of dry clothes in the tow car?

If you are a few miles off shore they would be more useful in the boat! :)

> >
> > Of course provide the obvious thing such as navigation lights, anchors,
> > sea anchor, motor, extra fuel system, charts, compass, GPS, tools, food,
> > etc. etc.
> I'd get a stainless steel shear pin for that 3.5 of yours.

I appreciate the suggestion, but wouldn't that defeat the purpose of having a
shear pin in the first place? I have made my own, using 5/32 diameter brass rod.
I will have to make sure i engage the drive at low RPM in future!

> >
> > I have almost finished my hatch boards, the rudder has been modified, I
> > have a keel system designed (not yet installed). I am trying to find 2
> > part pour-in foam, and foam block.
> Two part foam can be bought at West Marine. Orchard Supply Hardware sells
> some stuff in a spray can that might be easier. Styrofoam bead board sold in
> 2 or 3 inch thick sheets is often sold economically as insulation in places
> like Home Depot. You can build blocks by gluing pieces of sheet together .

Good idea! I have seen sheets of insulation, 4 x 8, but only about one inch
thick. I will follow up on that. I also saw cans of foam being sold as crack/gap
fillers for house insulation. it didn't say whether it was closed cell or not

"Pirate" Bernie...."HMS Pinafore"
Santa Paula, CA.