Boomvang Placement

[saildork]

On my Catalina 22, the boomvang attaches to the boom 2 feet aft of the mast, 20% of the boom's total length of 10 feet. This puts the vang at 65degree above the horizontal, and seems to limit my ability to put on more vang when I need it. Is there a rule of thumb or a formula that says where on the boom the vang should attach, or at what angle the vang should be for optimum performance? Should I move the boom attachment, or add another block to increase my purchase?

[Hartley18]

Your set-up, whilst not "ideal", doesn't seem too bad to me.

The ideal angle for a boom vang is 45 degrees, but on many boats this isn't practical for many different reasons so you get what you get.

If you can move the attachment to, say, 25% of boom length that would give you better control, but increasing purchase might have the same result.

Can you post a pic of your set-up??

Cameron

[saildork]

Cameron, I don't have a picture that I can post. Sorry. The placement I have is clearly not a 45 degree angle. This vertical leg of the triangle is about 30 inches and the horizontal is 24 inches. The boom bail is screwed into the boom so it will be easy to remove to a position further aft. This will give me more leverage, but I still wonder what, if any, formula is normally followed in the placement of a vang. All other boats I have observed have the boom attachment further aft on the boom. Then again, how far is too far?

Pat
s/v Stargazer

[sailboy21]

I wouldn't worry about it. 6" isn't worth drilling more holes into a very expensive piece of aluminum. Get some harken carbo air blocks or similar, something with roller or ball bearings. I think you will be pleased.

[sailingdog]

Saildork-

Does your boomvang look like this:

==============
........./
......./
...../
.../
./

or more like this:

==============
................./
............../
........../
......./
.../
/

If it is more like the former, rather than the latter, it will work to pull down the boom relatively well at all points of sail, but it will need much more leverage than if the bail were further out on the boom.

You probably want to move the bail out a bit further, since the angle between the boom and the boom vang is only 38.3 degrees or so... and you really want it closer to 45 degrees, if not a bit more. That will also give the boom vang a bit more leverage.

[RandyonR3]

The C22 boom is not strong enough to go cranking down on. I've seen them bend really easy. Its a week spot on the boats but because of the "one design" rules and force of rules on the factory, the boom was never upgraded..
I raced a C22 MKll - fin keel for a few years and because the boat was "black balled" by the association, I changed out the boom for PHRF racing.
To gain a vang on the boom, I upgraded to a C270 boom and cut it down to size.. worked great...
One of the problems was that once the vang was applied, and a good puff hit the main, and the main anchored at the rear, the force would pull the rear of the boom out of shape and bending it in the center....

[Hartley18]

Randy, many people put too much reliance on the vang as the only means of sail control and have it on way too tight anyway - then when they get hit by a gust, they wonder why the boom snaps..

The vang is supposed to be used in concert with the mainsheet/traveller and shouldn't be used as the only means to keep the sail flat. If you've got the boom out to leeward and you really need to keep the leech tight, use a preventer clipped to the toe-rail..

Cameron

[saildork]

SD - My vang looks more like the former than the latter. I'm thinking about moving it aft a little but as Sailboy says, why worry about 6"? I'll have to look at the boom and decide if I really want to put more holes in it. Maybe the fact that I can't get as much vang on as I think I should has kept me from bending it as Randy discusses above. Anyway, I guess optimum placement is wherever the sailor thinks it should be.

Pat

[philsboat]

To get more vang pressure pull down on the end of the boom as you are pulling the vang purchase. Be carefull not to overdo it as you could break something.This works on my Mirage 25.
Phil