Insight please - modifying a Boom Vang

[jsk]

Thanks in advance for your help and insight / musings!

Boat is a 2000 Beneteau 361 - old Forespar vang. The boom vang is dead - no longer holds up the mast - so I use a topping lift for that purpose. Topping lift keeps the boom parallel with the bottom of my furling main.

I'd like the boom vang to hold up the mast. The simple / cheap solution - mark the upper position on the inner / bottom tube when the boom is at the correct height - drill a hole through the inner tube at that point - install a pin through the inner tube (sticking out maybe 1/4 on each side) that keeps the outer tube from compressing past that point. Voila.

When sailing, the boom vang will only be able to compress to that fixed point. Which is OK, right? A full sail would raise the boom, the vang would still allow me to pull the sail back down to that fixed point.

Are there any downsides to this solution?

[Orion Jim]

What you are proposing seems like it would serve your purpose. Just to clarify, vangs do not “hold up the mast”.

[Jim Cate]

If you go this route (and it will work to some degree), be careful not to heave down on the main sheet when the boom is resting on the vang (sail down). Very easy to damage the boom with the huge load absorbed by the vang attachment.

Jim

[Jamme]

Originally Posted by Jim Cate

If you go this route (and it will work to some degree), be careful not to heave down on the main sheet when the boom is resting on the vang (sail down). Very easy to damage the boom with the huge load absorbed by the vang attachment.

Jim

My exact same thought. Thanks. OP may want to mark the main sheet at the exact point where any additional hauling in of it would start to compress the vang.

[ItDepends]

Another vote for this! Vangs absorb and transmit to the boom enormous loads. Care needs to be taken with modifications.

[cal40john]

First go for a sail. Measure the down angle of the boom on different points of sail. I would guess since I've never sailed with a main furler, that the boom perpendicular to the the mast to furl is not with a tight leech. To close the leech properly to go upwind in a fair amount of wind, the boom is going to be lower than perpendicular, so your fix on the boom vang will prevent that.

[Searles]

Simple fix ,remove vang from boom and mast ,drill out rivets on slide retainer seperate the two half’s fit a s/s spring of suitable strength and new length ,re assemble ,a cross bolt maybe fitted under the spring to easily adjust the load and overall length .⚓️⛵️

[cal40john]

Originally Posted by Searles

Simple fix ,remove vang from boom and mast ,drill out rivets on slide retainer seperate the two half’s fit a s/s spring of suitable strength and new length ,re assemble ,a cross bolt maybe fitted under the spring to easily adjust the load and overall length .⚓️⛵️

I think trying to get the spring perfect might be hard.

You could adjust the spring to make the boom too high then use the mainsheet to bring the boom to the correct height.

[jsk]

As always - you guys are awesome! Thanks for your insight!

[Patrigo]

Nine posts, and Orion Jim is the only person to point out that the discussion is not about a boom vang, but it's opposite. I would throw the lot away, and fit a Barton Boomstrut and Vang. I have tried topping lift, gas strut, spring strut etc. and nothing is better than a
Barton Boomstrut. It gets rid of the annoyance of a topping lift, and to me does the job perfectly.

[Jim Cate]

Nine posts, and Orion Jim is the only person to point out that the discussion is not about a boom vang, but it's opposite

Could you explain this rather obtuse statement, please? Seems to me that it is indeed about boom vangs, and that several useful comments have appeared.

Jim

[Patrigo]

JSK is working on holding his boom up, as he states that he is now using a topping lift. He is possibly going to put a pin in his defunct gas/spring strut so that it cannot go lower than allowed by the pin. A boom Vang pulls downwards on the boom. It is a system of pulleys used to keep the main from rising when filled by the breeze. My impression is the guy is making out a vang can raise and lower the boom!