Boom problem!

[Cardo]

So we've now got our mast back on after having the Bamar furling system overhauled. I'm about to put the boom back on and lo and behold I discover a new problem!

The pivot pin (is that what one would call it?) that the spinny wheels at the mast end of the boom rotate around seems to have lost one of its end caps.
Difficult to explain, so here's a couple of pictures:

This picture shows the left or port side of the boom. The pin is fine on this side.

This is the other side. This is where the end of the pin seems to have broken off. The pin can be pushed through from here, which would cause all the spinny wheels to fall out.

How can I fix this?

 

[sailorman]

They look like pop rivets to me.
is that a French boom

 

[Cardo]

They look like pop rivets to me.
is that a French boom

The "pin" is around 1/2" diameter and traverses the boom. Are you saying it has rivets at either end holding it in? Would I merely need to drill out the broken end and shove a new rivet in there?

 

[rob2]

Presumably you could contact the manufacturer and get a new pin? Otherwise get a new one made up or the original modified to take a screw in the end with a washer under the head to stop the pin from sliding out. A refinement of that idea would be to tap and thread a rod into the end, cross drilled for a locking pin of your choice.

Rob.

 

[merlin3688]

If they are rivets they are big! I think it would be best to replace the pin with a longer pin and centre punch the edges of the pin to stop it falling out, the pin could be a hollow tube but S/S

 

[Cardo]

The boom was made by Sailspar UK. They appear to still be in business, so I've emailed them with my piccies - will see what they say.

Depending on what they say, I'll contemplate the ideas put forward, cheers.

 

[merlin3688]

I think its a Francespar section, Sailspar are UK agents along with Eurospar in Plymouth, Francespar are now Sparcraft and used to be Isomat!

 

[Cardo]

I think its a Francespar section, Sailspar are UK agents along with Eurospar in Plymouth, Francespar are now Sparcraft and used to be Isomat!

Clear as mud!

 

[sailorman]

see #2

I think its a Francespar section, Sailspar are UK agents along with Eurospar in Plymouth, Francespar are now Sparcraft and used to be Isomat!

 

[Stemar]

Failing useful/affordable help from the manufacturer, I'd be inclined to drill the end of the pin and tap it for a set screw of suitable dimensions - maybe 5mm - with a penny washer to keep the pin from pulling through. If you can't get hold of a tap, you could use a self tapper, but tapping it would be a better job.

If the pin's ally, it won't be difficult. If it's SS, I'd be inclined to get a machine shop to do it for you

 

[pvb]

The boom was made by Sailspar UK. They appear to still be in business, so I've emailed them with my piccies - will see what they say.

It looks like the pin is listed as a spare part in the Sparcraft boom catalogue - see http://www.sparcraft.com/uk/technical_support/technical_brochures/booms/fichiers/bome_standard.pdf

 

[JayBee]

I have got one of these booms from Sailspar. The gooseneck end is very poorly designed. The jammers don't jam properly and worst of all the horizontal pin, on the left of your top picture, is retained in place by a long thin split pin, passing down through the centre of the swivelling jaw and through a hole in the pin . This is just visible in the photograph. Eventually, as the boom rocks slightly in normal use, the split pin gets amputated, leaving the horizontal pin free to work its way out and the boom to become detached from the mast. I had this happen to me twice. Fortunately I got to it before the pin dropped out entirely, and I have now replaced this with a stainless bolt and locknut. I suggest you might think about doing the same as a replacement for your sheave pin. It's not very elegant, as the gooseneck fitting is tapered and the bolt head and locknut do not sit flush with the casting. I am planning to get some tapered washers made in delrin to fix that.

Pretty bad show, Sailspar/Sparcraft.

p.s.
What are 'spinny wheels'??

 

[Cardo]

It looks like the pin is listed as a spare part in the Sparcraft boom catalogue - see http://www.sparcraft.com/uk/technical_support/technical_brochures/booms/fichiers/bome_standard.pdf

Nice one! Time to get part ordering, I guess...

 

[Cardo]

I have got one of these booms from Sailspar. The gooseneck end is very poorly designed. The jammers don't jam properly and worst of all the horizontal pin, on the left of your top picture, is retained in place by a long thin split pin, passing down through the centre of the swivelling jaw and through a hole in the pin . This is just visible in the photograph. Eventually, as the boom rocks slightly in normal use, the split pin gets amputated, leaving the horizontal pin free to work its way out and the boom to become detached from the mast. I had this happen to me twice. Fortunately I got to it before the pin dropped out entirely, and I have now replaced this with a stainless bolt and locknut. I suggest you might think about doing the same as a replacement for your sheave pin. It's not very elegant, as the gooseneck fitting is tapered and the bolt head and locknut do not sit flush with the casting. I am planning to get some tapered washers made in delrin to fix that.

Pretty bad show, Sailspar/Sparcraft.

p.s.
What are 'spinny wheels'??

Thanks for the advice.
Spinny wheels = sheaves, I think.

 

[William_H]

I couldn't make much of the pin attachment from the drawings. I did wonder if it has a circlip set into a groove in the end of the pin.
It does seem unlikely the pin would break off. Anyway as said a bolt with nylock nut would do perfectly to replace the pin.
good luck olewill

 

[Cardo]

Sailspar UK replied to my email. They simply suggested riveting a SS washer onto the end. I think this is pretty much what was on there originally, but the rivet has given up the ghost after 20 odd years.

 

[JayBee]

Off topic, but still with Sparcraft/Sailspar:

I ordered a Sailspar spinnaker pole bell fitting, to fit the track on my Sparcraft mast. This would not lie flat against the mast track when not in use and projected out at a substantial angle, looking terrible, ready to foul headsail sheets etc. and just not right.

I phoned Sailspar and found that they were aware of the problem. They offered this bodger type advice: 'Take a file to it and remove (a lot of) metal until it lies as it should.'

They also told me that they had been in touch with Sparcraft to draw their attention to this and were met with the equivalent of a gallic shrug.

caveat emptor

I do like my Sailspar/Sparcraft mast, though.