Boom Vang / Kicker Refurbishment

[Blue_Pearl]

Does anyone know if I refurbish the ram to it's original (or close to) state, would it be strong enough to support the boom and mainsail ........... ie remove the need for a topping lift? The reason I ask is because at the moment the topping lift is in fact the main halyard. Not a problem in itself but a minor fiddle to get topping lift / halyard up to the mast and secured whilst in any sort of chop. I know this could be carried out before leaving the mooring but I'm just trying to be clever (not smart) and use the boom vang / kicker.

 

[barfly4657]

Boom vang

We had a gas strut like that and it supported the boom + main, no probs - that's what it's designed to do and we took the topping lift off the boat.
However, the result was a soggy, bouncy situation so for Harbour Stow the main halyard was taken to the boom end as a topping lift, while Ready for Sea entailed moving it back to the main again.

 

[lw395]

I had a Lightwave 395, it did not have a topping lift either. The strut kicker I had did not seem to be a gas strut, I believe it is just intended to support the boom at a low level, just high enough to clear the deck, winches and wheel during reefing. I just lived with it like that, and tied the boom off to one side when the sails were down. My boat was a little non standard so yours may differ.
You might be able to drill the strut so that you could put a pin through it, holding the boom higher? You can always pull on a reefing line (with main hoisted) to raise the boom to get the pin in?

Hope this helps, sorry if its not what you want to hear.

 

[Norman_E]

If it is a gas strut vang, like my Sparcraft, do not under any circumstances do away with the topping lift. Gas struts can and do fail. The first sign is that the oil in them leaks out, which you may not notice if it remains contained within the vang. The second sign is the boom dropping with a crash when you let off the mainsheet. Fortunately when mine failed there was nobody underneath it. The gas strut was put in in April this year, and failed after less than three weeks of actual sailing. I have now bought two custom made stainless steel springs from Leeming & Peel in Bradford http://www.leemingpeel-springs.co.uk/index.html and will fit them when I go back to the boat at the end of August.

 

[Blue_Pearl]

If it is a gas strut vang, like my Sparcraft, do not under any circumstances do away with the topping lift. Gas struts can and do fail. The first sign is that the oil in them leaks out, which you may not notice if it remains contained within the vang. The second sign is the boom dropping with a crash when you let off the mainsheet. Fortunately when mine failed there was nobody underneath it. The gas strut was put in in April this year, and failed after less than three weeks of actual sailing. I have now bought two custom made stainless steel springs from Leeming & Peel in Bradford http://www.leemingpeel-springs.co.uk/index.html and will fit them when I go back to the boat at the end of August.

That's exactly why I want to get rid of the main halyard as the topping lift. When I release the clutch while the main halyard is in topping lift mode, the boom drops about 18" and if not sheeted in causes more unwanted hazard.
LW395 - I think mine is the same as yours was, but I would like to get the boom lifted by the ram as high as possible and then use the orange kicker adjustment to counteract the lift and thus keep the boom at a reasonable height and fairly stable.

The other option would be to run a topping lift up to one of the spare sheaves (I assume there is one).

I'll give the guys at Leeming & Peel a call to see what info they need to price up a spring (or two).
Thanks

 

[lw395]

Topping lift

Another possibility is a boom lift tackle running to a point some way up the backstay. At least it would be easy to fit mid season. not as useful when reefing etc as a proper masthead topping lift.
My boom was v heavy, the springs would have to be stout. This then makes extra work for the kicker and may mean the kicker releases with an unexpected surge from time to time? Not damped like a gas spring?
I think I'd be looking to see if there's a spare sheave up top!
Cheers,

 

[fishermantwo]

I don't have a topping lift at all. I use a fibreglass rod that has some prebend to support the boom. Boom vang behind it is fairly easy to overcome the rod. Its made from an old fibreglass game stick cut down. Was at a recycling shop recently and they had heaps of snow skis, reckon these could be adapted to do the same job, no gas to escape, springs to corrode etc.

 

[rudolph_hart]

Does anyone know if I refurbish the ram to it's original (or close to) state, would it be strong enough to support the boom and mainsail ........... ie remove the need for a topping lift? The reason I ask is because at the moment the topping lift is in fact the main halyard. Not a problem in itself but a minor fiddle to get topping lift / halyard up to the mast and secured whilst in any sort of chop. I know this could be carried out before leaving the mooring but I'm just trying to be clever (not smart) and use the boom vang / kicker.

Just a word of caution: I took my gas-strut vang, which I fitted 4 years ago to my Dehler 35, back to Sailspar to fix a part that I had broken. They told me that they need a very powerful haydraulic bench ram to compress the unit during assembly, and for that reason were glad that they did not have to dissasemble the unit to carry out the repair.

I like LW395's idea of fitting a pin that will either lock the unit at a certain extension (similar to the Spinlock unit) or limit the compression travel. That would be a very good safety measure.

 

[Norman_E]

To answer both Blue Pearl and IW395 gas struts do not have a great deal of damping, but differ from springs in one important way. In a gas spring strut there will be very strong force right from the initial movement, because the strut contains nitrogen under very high pressure, and the force increases by a fairly small percentage over the available travel. With a steel spring there is no force at all until you start to compress it, and the force increase is linear at the quoted spring rate.

For the above reason you need to know how much force the spring needs to exert to balance the system, with the boom at its working position, so that the manufacturer can calculate the required spring rate.

I was tempted to have springs made with a degree of pre-load once installed, but decided against that and had them designed so that I could haul up the boom to the original full extension of the vang and remove all load from the spring to stop it becoming weakened when the yacht is not being used. As I required 260 KG force when the spring was compressed from 600mm to 350mm this needed two springs, wound in opposite directions and placed one inside the other. The outer spring is made of wire about 6mm thick, and the inner about 4mm. Not cheap, because they are one-off items in stainless spring steel, but hopefully will be a good long term solution.