pop rivets

[matoi]

Hello!

Could someone, please, recommend what type of pop rivets are best for use on aluminium mast and boom – stainless steel/aluminium/monel ?

I ask because I would like to mount a mainsail feeder onto the mast track, and move the reefing fittings on the boom to a correct position.

Also, do you think a 3mm wire jib halyard would be ok? I cannot find a 2.5mm wire which was the diameter of the original halyard.

Thank you + best regards,

Mato

[Dave Barker]

Hi Mato,

I use monel rivets and these are usually the only type stocked by most chandlers. AFAIK they are significantly stronger than aluminium rivets, and more resistant to corrosion, although I’m not certain of the situation regarding galvanic corrosion. (It’s probably worth using a paste such as duralac, if possible, to avoid this).

(You know what Ralph would say about the reefing fittings – at least the fixings for the ends of the lines – use sliders instead of rivetted fittings, so that you can adjust the position freely!)

I can think of no reason why 3mm wire wouldn’t be OK for the halyard, if it’s sufficiently flexible. You could email Ian Porter for a much more knowledgeable response than mine… (ian_por.porter@btconnect.com)

Has your sailing season started now, Mato?

[matoi]

Hi Dave!

Thank you for a quick reply. My season is just starting – I plan to sort out all the modifications soon, and than go for a 10 day or two week cruise with my father in June. We have prepared a fitting which would hold a drain tube within which the bowsprit would run, so that it doesn’t interfere with drybags and other stuff. There are other modifications as well (like improving the reefing system), which all need to be prepared very thoroghly as the boat is stored 400km away from where I live…

Are you able to give me a bit more detail on the fittings that you have involved for the reefing line? I vaguely remeber that such a system includes a twisted shackle, but can’t assume which size and if there is anything else besides a small block attached to it….

I presume you are sailing a lot already and wish you strong winds and calm seas!

Thank you + best regards,

Mato

[Dave Barker]

Mato – I’m not sure which part of the reefing system you’re talking about, so I’ll describe each part for you.

The far end of each reefing line (on Cockle) is attached to a clip something like this…

…which is rivetted to the port side of the boom, and should be positioned to make the line give a 45 degree angle of pull aft and down when the reefing line is tightened. Ralph suggests using a boom slider instead, because it is adjustable, so you can use any mainsail, with reefing points in any position. This is the sort of thing – it fits into the track under the boom…

Each reefing line then passes up and through the cringle in the leech of the sail, then back down to the boom, where (on Cockle) there is a small cheek block rivetted onto the starboard side of the boom (one for each line, opposite the relevant clip), also placed to give a 45 degree pull on the cringle.

Each line passes forward along the boom. Ours go through some little bushes to support the lines and keep them tidy, like this:-

Near to the mast end of the boom each line passes through a clamcleat, e.g. CL211 Mk2 and then another cheek block, which allows us to pull the line downwards. This is perhaps the least successful part of the system, because the block gives a limited range of pull angle, and the lower one (first reef) has to be pulled slightly away from you (it is slightly “under” the boom because of the shape of the boom).

We don’t have a keeper on the clamcleats at the moment – these might be a good idea, to make releasing the lines a bit easier, but I haven’t tried this out, so I can’t recommend it yet.

The reefing lines follow a parallel path all the way, which helps in setting everything out. The cheek blocks at the stern end of the boom are the most tricky to position correctly – until they are fixed you can’t easily try them, but once they are fixed you don’t want to move them!

Please feel free to ignore all of the above – I’m sure others will have better systems than this!

Good sailing!

[matoi]

Thanks Dave!

Regarding the clamcleat keepers – I just got some of those a few weeks ago and installed one. Haven’t tried it at sea yet, but it does seem promising.

Best regards,

Mato

[W10143]

Mato

If you use Boom Slides, you can tie or shackle your turning block onto the slide – this then allows complete adjustment of the system ala Ralph!

David

[matoi]

Thank you David!

I will go with this adjustable system then.

Best wishes,

Mato

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