Re: Leaking P19 keel trunks -- a diagnostic approach.
Sun, 29 Aug 1999 11:14:51 EDT

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West Wight Potter Website at URL
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In a message dated Sun, 29 Aug 1999 10:49:47 AM Eastern Daylight Time, writes:

> Has anyone tried to understand why this keel trunk leaking problem confined
> to the !-19's? The P-15 also has a very loose keel situated in, what I
> believe, is a similar trunk, and yet you don't hear of this problem with the
> P-15's. I have never had a drop of water come through the trunk of my P-15.
> Not a drop. The P-15 does have a habit when beached on a gravel beach with
> chop bouncing the hull on the beach, to get gravel jammed in the keel trunk
> making dropping the keel difficult until you can work out the stones jamming
> the keel. I don't know if that happens to the daggerboard of the P-19. I
> kind of doubt it.
> What is different between the design of the 15 and the 19 trunks that allows
> this inconvenience in the 19's?
> Geoff
> P-15 Lollipop
> N. Lake Tahoe, NV

Hi Geoff and gang,

I'll hazard a guess on this one. It would have to be confirmed by taking a look at the two boats.

First of all, not all P19 keel trunks are the same. The old ones (HMS18's) were built with a separately molded keel trunk that was then glassed onto the the hull. The keel trunk was designed by Herb Stewart, the designer of both the original HMS18 and the modified MKII P15 which was introduced in about 1975.

The original HMS18's have a lot of extra room all the way up the trunk to dissipate the pressure on any water that gets forced up the trunk. They don't leak a drop or need any gaskets. It would be interesting to take a look at a MKII keel trunk and compare.

When Joe Edwards bought the HMS company, he changed the way they made the keel trunk. Basically, after the hull was molded, he turned it upright and stuck a waxed model of the keel through the slot in the bottom. then he wrapped fiberglass around it. After it set, he just slid the keel out, cut off the top part flat and was done with it. These keel trunks fit the keel loosely at the bottom and very tightly at the top -- and they pump a lot of water. My boat is a 1985 P19 built by Joe Edwards.

I'm not sure how IM makes the P19 keel trunks since they took over the company in 1992 or 1993. I do know they flex less then the keel trunk on my 1985 P19 and look a lot prettier than mine does.

With respect to the MKII p15's -- these boats are still being made with the original trunk mold as designed by Herb Stewart. Unfortunately, Joe Edwards discarded the original keel trunk mold for the HMS18's.

Maybe the common thread here is that Herb knew exactly what he was doing when he designed the keel trunks for both the HMS18 and the MKII P15. he designed them with an eye to the pressure build up when the boat is moving thru the water or pounding on swells/waves.