Boom running rigging replacement

[AlexL]

I've got a First 21.7, planning to replace all the standing and running rigging this winter.
The boom is currently in my garage, and i'm measuring up all the lines to replace. Reef lines go from one end to the other, simple - i'll just pull a mouse line through. The outhaul on the other hand appears to have 3 ends so I'm assuming there's a shuttle block in the boom which makes it difficult. I could leave the line tied to the block (not sure which 'end' that is, but I'm sure I could shine a torch and see) and then just mouse line and replace the other bit, but I'd like to replace it all if poss.

Any ideas? the only thing I can see is to drill out the rivets for one of the end fittings and then re-rivet later - any risks / gotchas with this?

 

[andsarkit]

Drill out the rivets and use boiling water and a rubber mallet to remove the end fitting. With luck it will come out easily but if you leave it a few more years it will be even more difficult to remove. There are many possible internal arrangements and you will not know until you have a look. A common one is in the diagram below. It might be better to remove the gooseneck end first as the tail of the purchase might be attached there.
I had a 4:1 purchase with double blocks that I replaced with a 4:1 cascade that was much smoother to use. Refit the end plug with grease so it will come apart easily next time. I used large self tapping screws instead of rivets as I will probably open it up again in another 10 years.

 

[AlexL]

thanks - I'll open it up tomorrow and have a look.

 

[William_H]

If yours is like my 21fter he outhaul is not so easy to release to get more camber in sail. There is friction especially in the sliding attachment of the clew.
if that has been the case I would suggest abandon the internal tackle. Take the outhaul line to the clew and through the eyelet and back to an external attachment. Thus making a 2 purchase at the clew. The line then goes through boom and down to turning blocks and back to a winch. The winch gets you power to pull it out but easier to release pressure to ease it.
Re removing end plug of boom. You may have serious difficulties getting it off. Hot water etc but ultimately you may have to cut the boom so shortening it then peel off the corroded ali from the plug. As said lots of grease or duralac to avert corrosion again. ol'will

 

[oldbloke]

I àgree with William H, use 3mm dyneema, which you can splice or tie to something thicker if needed for cleating. If there is space you could add a 4 to 1 purchase on the end of the boom. With 3mm string and little bullet blocks you don't need much space.

 

[AlexL]

If yours is like my 21fter he outhaul is not so easy to release to get more camber in sail. There is friction especially in the sliding attachment of the clew.
if that has been the case I would suggest abandon the internal tackle. Take the outhaul line to the clew and through the eyelet and back to an external attachment. Thus making a 2 purchase at the clew. The line then goes through boom and down to turning blocks and back to a winch. The winch gets you power to pull it out but easier to release pressure to ease it.
Re removing end plug of boom. You may have serious difficulties getting it off. Hot water etc but ultimately you may have to cut the boom so shortening it then peel off the corroded ali from the plug. As said lots of grease or duralac to avert corrosion again. ol'will

thanks - I'm not quite sure I understand the layout - can you sketch?

 

[oldbloke]

William H will be fast asleep as he is in Australia.

 

[AlexL]

This is what I’ve got. End fitting came off easy enough. Seems odd that the “3rd” end is just tied off on the bottom of the boom. It’s just round a pin , which I suspect it’s supposed to be tied to, but access is tight. I could possibly add a cascade to that and lead it back.

 

[oldbloke]

So, all you have there is a 2:1 and as it cleats on the boom and is not led to a winch is a bit mean. You would be lucky to adjust it under load. William's suggestion is rather than shakling the line to the clew, pass it through the clew ( or a pulley attached to it) and make it off to the end of the boom, giving you a 4:1. My suggestion is to maybe set up a 4:1 between the clew and the boom end, giving either a 8:1 if you retain the pulley in the boom, or 4:1 if you get rid of it. Plenty of people never adjust the outfall in which case just tie it off with a piece of sting

 

[William_H]

thanks - I'm not quite sure I understand the layout - can you sketch?

Yes sleeping soundly after a pleasant race on Swan river. Funny old wind started nice but dropped and seemed like we might be becalmed. Got to 37 degrees early but cooled off a bit.
Sorry my sketching is not up to scratch. I have a saddle bolted to the top of the end of the boom just off to one side. So the outhaul line comes out of the end of the boom at a sheave. Goes through the eyelet and back to the saddle. The line inside the boom goes straight though to another sheave near the gooseneck where it exits. In my case down to a turning block on the cabin top near mast base thne back to winch and cleat. So no complications inside the boom and easy to release the outhaul tension.
A said it is not silly to simply tie the outhaul off at a reasonable tension. Strong winds not a problem if you reef early so negating role of outhaul. ol'will