Re: P-15 Boom Vang

TillyLucy@aol.com
Fri, 3 Sep 1999 01:28:47 EDT


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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Since a couple people have asked, here's the "recipe" for my el-cheapo build
it yourself boom vang.

Shopping list:

15 ft of 1/4" Dacron line
qty. 1 Harken 244 Fiddle block w/ integral v-cleat West Marine 289975 $17.18
qty. 1 Harken 235 Single block w/ becket and shackle West M. 253351 $9.39

The above is all you need to make the vang. Attaching it to the mast and boom
can be done in a number of ways, most of them simpler than what I did. Since
not a whole lot of force can be put on the slender boom of the P-15, an
eyestrap on the bottom of the boom and some kind of bale at the bottom of the
mast, each attached with pop-rivets is likely to be cheap and adequate. Thats
the way the blocks for the mainsheet are held on and it appears to work fine.

But, since I am a little twisted in the head and didn't want to install
something where the fasteners are loaded in tension I did something that is
simple when you look at it, but a little difficult to explain:
On both the mast and the boom end I threaded a short piece of 3/16" line
through a stainless steel ring (West Marine 111609 $4.49) and tied the ends
of the line together so I have a loop of line with a ring on it. Wrapping the
loop around the spar, pass the ring through the loop -as it is pulled tight
it grips the spar. To locate the loop on the spar I mounted a little plastic
fairlead (West Marine 111064 $2.59/pair) on the top (!) of the boom and on
the forward side of the mast. This way, the stresses caused by the vang are
distributed over the contact area of the loop of line and the screws (that
hold the fairleads on) have very little force on them, and all of it in
shear. I'm not recommending that anyone copy my example, but that's how I did
it.

The rings are nice for rigging. I used to remove the vang completely and
therefore had a fast-pin on the boom end and one of those cheap brass snap
shackles on the mast end. In my quest for ever-shorter rigging time I now
leave it attached to the boom all the time and store the boom in the cabin.

If anyone wants more details, email me and I'll do my best to explain it
better.

Dave Kautz
P-15 #1632 Tilly Lucy
Palo Alto, CA

In a message dated 9/1/99 7:33:32 AM Pacific Daylight Time,
Stallings_Mike@prc.com writes:

<< I just bought a P15, and one of the things I'm most pleased about is
being able to
cheaply and easily build my own contraptions. I'd think I'd like to add
boom end sheeting,
and know I'd like to add a boom vang.

Since there are at least two of us, and probably a lot more, who
would be interested
in your ideas, you might consider posting them (or at least send me a copy).
It sounds like you
have done some experimenting and learned to avoid some hard knocks. :-) I
just need a
few ideas to get started, you don't need to go to any trouble about it.

Thanks,
Mike Stallings
556-2298 (W)
'85 P15, Norfolk VA
>>