Spinnaker size?

[Pauly]

Hi All, I'm considering equipping my boat with a spinnaker, so whilst the mast is down I will fit the appropriate tackle to the mast to carry one. My question is, how do I work out what size sail would be suitable for my boat? It's a 21' bilge keel with a masthead rig, and although the mast is down I haven't had a chance to run a tape measure along it yet. I'm guessing somewhere around 26'-28'.
Any ideas?

 

[PuffTheMagicDragon]

If you know the model of the boat, chances are that you will find full specifications on the internet.

 

[Pauly]

Hi PMD, sadly there is very little info on t'internet regarding my boat. However, I have found this

http://www.baconsails.com/measuring

which pretty much answers my question.

Google is my friend.

Thanks anyway though.

 

[Tranona]

There is no fixed size for a spinnaker. Suggest you discuss what you are looking for with a couple of sailmakers who will advise you on the options.

 

[GrahamD]

If you are going to look for a secondhand sail you may find that a spinnaker from a bigger fractional rig could also fit your masthead rig. Once you have accurate values for your boat, you could investigatethe spinnaker dimensions of racing keelboats such as Soling, Dragon, Squib or even J24 to see if they might fit. Some boats change their sails surprisingly frequently, so it might be worth checking the relevant class association website.

 

[William_H]

Spinnacker size is a bit like jib size and depends on the wind at the time. On my 21ft lift keel I have 2 spinnackers one is the origianl spec size and the other much smaller.
The smaller one was from a 14ft skiff very flat and obviously not too big. It is great for when there is a bit of real wind and is very mangeable. It is good because over 15 knots my hank on jib is really quite tiny so spin helps increse sail area down wind or reaching. It really gets into the heads of the opposition when they see colour but think wind is too strong for their own spin. The big original is good for lighter winds.
So I suggest you look around for second hand spins (and do check for spins from larger dinghies).
The height of the top of the spin halyard to deck is pretty much the luff length. The width of the spin being usually comensurate with the height.
However a spin is fairly easy to cut down. Use a domestic sewing machine and thread. To reduce width you can fold in the middle sew a seam then cut off the excess.
To reduce height it is a bit more difficult as you will either cut a bit out of the middle across the spin or cut the bottom off and refit eyelets or sew in SS rings on tapes.
If you get s/h spin for the right price you can have some fun without too much concern but in any case er on the small side.
However do not get a spin that is too short as a spin that is not up to the mast at the top can gyrate around and be a beast. good luck olewill

 

[Pauly]

The intention was to go for second hand for all the reasons that Graham and Will have pointed out. Didn't consider going for 2 sizes, but that is a good idea too Will. There seems to be a reasonable selection on everybody's favourite auction site, but class association websites might also prove useful. Hopefully I shouldn't have too much trouble picking something up.

 

[PuffTheMagicDragon]

When I had a little Vivacity I had bought a second-hand spi from a place in Emsworth that regularly advertises on PBO. The friend who bought the boat from me was reluctant to try the spi so I cut it down into an asymmetric for him. He was very pleased as he found it less of a hassle to use on his own.

 

[Pauly]

An as symmetric might be nice, as you say easier to handle, especially as my crew (the missus) is short on experience.