IOMICA Forum

Good day to you all!

Like Martin, I own a Voyager (for two whole weeks now), and enjoy sailing her.
After a substantial amount of reading on the forums, I'm well aware that she is no IOM, judging by the rules.
I have no intention of racing (yet) so that's no problem.

My biggest issue are the stock sails, that look reasonably in the (warm) workshop, but lose their shape when sailing in cold/damp weather after ten minutes, stretching like mad and bagging all over, downwind it looks like you've got a spinaker as a main...., sailtrim is a joke with these sails!

What I would like to know is, if I can take a IOM sailmeasurement, like the 1180mm version on the site of Anders Wallin, (which happens to be the size of the Voyagers carbon fiber mast) and put those on the Voyager?

-Would I have to move the mast back or forth,because the center of effort would move forward quite a bit, as the stock main boom is 440mm long (versus the 360mm in the drawing) and the jib boom is 300mm long (versus 375-385mm in the drawing)?

Currently the mast is 60mm forward from the front of the keel.

Or, should I use a sail-designing-programme like Sailcut4 (free) and make an effort to design a new set within the measurements of the stock booms?

Looking forward to your advice(s).

Regards, Jan.

most IOM sails are made out of polyester draughting film. thickness is usually around 50 microns (0.050 mm) with special lightweight sails being maybe 25-30 microns.
The material is available at least through artists/architect type of shops and is not expensive although you might have to buy a whole roll at a time.

If you want new competitive sails for your Voyager I would suggest either ordering custom sails to the current dimensions from a sailmaker or, if you can find bigger IOM or other class sails more cheaply/easily then you could carefully cut those down to the measurements of the current sails.

Thanks for the advice!

As IOM sails can't be bought in the shop around the corner in this part of the Netherlands, either new or used, I think I'll start with making a copy of the stock sails in drafting film.

At work we use Mylar sheets, but with a thickness of 100micron, I guess this will be way too heavy (maybe for a set 3).
I'll phone our supplier, see what he can get me.

If I can get those sails to work, I'll give the panelled ones made of spinaker a go.

Another question:
My mast is 120cm above deck, ballast is 2200 grammes with a draught of about 350cm, does that make the stock sails a rig one or two?
Sailsurface is 39 square dm.

Or: if it's a rig two, could I use a longer mast (and more sailsurface) to sail better in light conditions?

Regards, Jan.

pompebled wrote:Another question:
My mast is 120cm above deck, ballast is 2200 grammes with a draught of about 350cm, does that make the stock sails a rig one or two?
Sailsurface is 39 square dm.

As you have noted yourself the voyager is not an IOM so it is hard to compare the rigs...
The mainsail luffs for the three IOM rigs are max 1600, 1180, and 880 mm.
there is a drawing at
http://www.iomclass.org/class/unofficia ... 3mar08.pdf

the draught of an IOM is 370-420mm and the weight of the keel is 2.2-2.5kg. With a maximum depth and maximum weight keel the no 1 rig can be used up to about 5 m/s.

Thanks for your info Anders,

I'll adapt the 118 cm luff rig for my boat and see how it works.

After that I can always make a longer keelfin, a taller mast and see what I can get away with, square inch-wise.

Regards, Jan.

The sails are probably the biggest contributing factor to boat speed so I would expect that replacing the stock sails would lead to a big performance increase. However you will almost certainly have to move the mast aft. Typically an IOM has its mast 20mm forward of the leading edge of the fin and I find that it is necessary to be able to adjust the mast position for each of the rigs. If this can be easily achieved on the Voyager then I would use IOM sail dimensions. If not I would copy your existing sail dimensions

Please keep us up to date of your progress

Regards

Chris

Thanks Chris,

I'll start with a copy of the stock sailmeasures in Mylar.

As the Voyager has the mast through the deck, moving it back would require some surgery to get enough support for a mast rail.
Also the rigging would need some modifications.

I'll keep you posted.

Regards, Jan.

Hi guys,

Something I could not find in pictures or other topics: do I need to reinforce the joints between the (Mylar) panels, made with 6mm doublesided tape, if so, how?
Or should it hold?

I used selfadhesive spinaker for the luff of the main, is that sufficient, or should I've incorporated a line?

Be gentle, it's my first attempt.

Regards, Jan.

Hi guys,

Made my first set of sails this weekend (mylar) and tested it on sunday afternoon.

I must say, it did not look that bad, for a first go, I did not get the curve right in the lower mainsail seam and had a nasty fold in light winds, which disappeared in a gust,so I guess the curve is too big.

As I had only transparant material at hand, which is on the thick side (96Mu), I had trouble seeing what happened when the boat was a bit far out, I'll get thinner and non-see-through this week.

I have a pic, but not webspace, so that'll have to wait.

Regards, Jan

As the search for thin mylar film continues, I made a sailset out of spinaker, which I had lying around for years, it's the paperthin stuff that wrinkles like mad and is one of the noisiest materials I know.
Our cat scares herself when she tears through the heap of spinaker on the floor....

I tested last sunday in a lot of wind (frankly too much for this size rig) in a sheltered spot.

To my surprize it has an acceptable shape and needs no battens, at least in a yesterdays condition.

Probably due to the rather thin material the sails have rather a lot of twist, or was it the gale-force wind?

I didn't come around change the set-up as my servo arm broke in a gust.
Made a new one out of 1mm carbon sheet, but had no opportunaty to go testing because of the foul weather.

Regards, Jan.