Bending the P19 Mast, genoa tracks, and pointing higher
Wed, 10 Feb 1999 14:22:38 EST

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West Wight Potter Website at URL
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In a message dated 2/10/99 10:04:55 AM Pacific Standard Time, DAVID_KAUTZ@HP- writes:

<< Even if you were to test a sample section of the same extrusion, I would
suggest a generous safety factor since the variability in alloying, heat
treating, anodizing and environmental damage will have a profound effect on
Hi Gang,

Well, I guess someone will have to donate his mast for such a test to get the
definitive answer to "How much can you bend a DM5 mast on a P19 before it

Actually, somebody already did, albeit inadvertantly. wrote:

<Rest assured, you will probably never reach the SNAP part, unless you really,
really try.. It is a long story, but I have a P19 mast in my garage (a
trophy I guess) that has about a 30 deg permanent bend in it, when it had a
conflict with an overhead power wire. The 'give' point was a set of <factory>
holes apparently used for the gin pole mast raising system. The wires caught
on that little cast masthead 'ornament', and didn't let go until the mast bent
to it's current position. Didn't pull any shrouds out of the deck, didn't
punch any holes through the cabin top, just tweaked a mast. >

After all the discussion, I'm pretty comfortable with the idea of putting a
*modest* bend in the DM5 mast to flatten the main, after checking to make sure
the masthead is firmly attached as Jerry recommended. This is based on Mr
Dwyers (of Dwyer Mast Company) opinion that it's safe and also a tour of the
boats in storage at the local marina. Most of the small boats there (20-25
foot range) have similar weight masts and they all have adjustablbe backstays.

The DM5 mast seems to be plenty strong enough for the P19 and it only weighs
1.14 pounds per foot, compared to my DM6 mast which weighs about 1.5 pounds
per foot. I'd say it was a smart move to go the the lighter mast. You ought
to try hoisting my DM6 mast at 35 pounds instead of the DM5 at about 22
pounds. GRUNT!

Of course, your mileage and comfort level may vary.... I'm not going to
guarantee that you can do this to your DM5 mast because I don't have any
experience with the backstay on a DM5 mast.

Now, on to the topic of pointing higher:

I've mentioned in previous postings the advantages to flattening the mainsail
by tightening the backstay already. Flatter draft, less power, less heel,
longer time till you reef, etc. But there's another one that I haven't
already mentioned.

If you have a deep draft in your mainsail, you can't sheet the jib in really
tight without backwinding the main. This limits your ability to point really
high. However, if you flatten the mainsail draft, then you can sheet in the
jib really tightly and both sails will still draw well. You can really point
higher now.

This isn't just one of my theoretical musings <g>. I actually tested this on
the water last week with the sailmaker from UK Sails on board to get his
expert opinion and advice. With the backstay adjusted to flatten the middle
of the mainsail, and the lapper sheets tied to the teak handrail on top of the
doghouse, the boat pointed much higher than with the lapper sheeted anywhere

So right now I'm drilling holes in my doghouse roof and installing tracks and
cars along the outboard edge, just outboard of the teak handrails. I'll let
the gang know if I discover any unforseen problems, but so far it's looking
really good.

Judy B.

Judith Blumhorst, DC
HMS18/P19 Fleet Cap'n, Potters Yachters
1985 WWP19 #266 "Red Wing"
SF Bay, CA