Mast Fittings

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Plank

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I have an aluminium mast and intend to fit a metre length of track to allow adjustment of the spinnaker pole attachment height. The track comes with plastic inserts for the attachment holes. Is it OK to use pop rivets and should I use alloy or stainless? Is it preferrable to use machine screws? Do I need to use insulating paste or similar if the track is alloy?
Experience welcome!
Regards
Plank
 
If it was me I would use Monel rivets and barrier paste (Duralac or equivalent) to coat the rivets.
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"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>
 
Welcome to the forum Plank.

As a new user you should take Cliffs advice on matters like this. He is one of the resident metalurgists.
 
Yep, Cliff is right, Monel and Duralac.
Coat the mating surface of the track too. Masking tape the area before application to make a really neat job. Dont leave the masking tape on for more than a few hours - it will dry and stick horribly to the mast.
 
[ QUOTE ]
Yep, Cliff is right, Monel and Duralac.
Coat the mating surface of the track too.

[/ QUOTE ]Assuming the track is Stainless Steel that would be a good idea indeed, but if the track is Aluminium I would not be too bothered coating the back of the track.

As the rivets will need to be tight do use a set of lazytongs so as you can get your weight behind then and help keep the track tight against the mast.
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hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>
 
[ QUOTE ]
Dont leave the masking tape on for more than a few hours

[/ QUOTE ] I did not take much notice at the time but i seem to remember seeing various "grades" of masking tape in B&Q, or similar, that could be left on for longer.
 
[ QUOTE ]
As the rivets will need to be tight do use a set of lazytongs so as you can get your weight behind then and help keep the track tight against the mast.


[/ QUOTE ] I take your point about helping to keep the track tight up against the mast but pop rivets do pull the joint together as you pop them provided you don't start with a wacking great gap of course.

Personnaly I found that with the lazy tongs type you need the structure firmly supported as you have to push quite hard and that there was a risk that when the rivet pops the tongs skid off the top of the rivet so that the projecting bit of mandrel gouges its way across the anodising while you go Rs over tit. I confess I've only used them once but I thought I would try the long handled 2 handed type if the need arose again.
 
[ QUOTE ]
I confess I've only used them once but I thought I would try the long handled 2 handed type if the need arose again.

[/ QUOTE ]

If you're popping 5mm monel rivets with a two-handled type, I think you'll need very l-o-n-g handles and very strong arms!

While I would use lazy tongs to get the force required I doubt how easy it will be with the mast standing. When I did mast steps the thing was horizontal on trestles and I had to put my weight over the lazy tongs to get the rivets to set.
 
Re lazy tongs I found that a compressed air powered pop rivetter was not much more expensive than lazy tongs and much easier providing you have an air compressor. Chinese ones here are very cheap 40 squid equivalent but then I know prices are higher in UK. You should have a look around however.

Plank does not say what kind of boat in his bios. Unless it is a large boat requiring dip pole jibing of spin then I reckon a fixed position spin pole ring is the best (snotter) we call it. End for end jibing.

The racing books say you should keep the pole horizontal to give the max effective pole length but I don't think that matters much and 15 degrees of pole up or down does not reduce the pole reach very much. or increase stress. so you don't need a track.
good luck olewill
 
Thank you all for your replies. None of you mentioned the screw option, I take it that screws do not give as strong a fitting as the rivets?
The boat is a Young 88. As we run 3 different sized kites with the pole too low for the smaller ones it tends to fall back all the time and we think that this will improve the setting.
 
[ QUOTE ]
Thank you all for your replies. None of you mentioned the screw option, I take it that screws do not give as strong a fitting as the rivets?

[/ QUOTE ]In one!

Do make sure you select rivets to neatly fit the holes in the track and drill the holes in the mast the correct size - not too big.
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hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>
 
high Plank yes I reckon screws in a tapped hole are quite OK for attaching the track.

Back to Spinackers. I race each Sunday and some friends have smaller spins for our regular 20kt seabreezes. Thhey have used spins from smaller boats. They look awefull being wide and short they aree flown high. Just where you don't want a spin.
i reckon a smaller spin should be full height but narrower right across but especially at the shoulders.
My small spin is from a 14ft skiff and is full height but almost looks like an asymetric in that it is tiangular shaped and reaches really well. (but then that is for a 21fter).
So I still reckon get a larger spin and reduce its size by making more narrow rather than fly a short spin high. good luck.
Remeber the advice I give to my friends...Keel down mast up... don't get it the other way round as they and I ofteen do. (or try to) olewill
 
What is Duralac?
used lanoline (expensive australian sheep fat, you might even eat it) to attach stainless steel fittings to aluminum, very satisfying
 
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