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Polypropylene sails

Posted: 14 Mar 2005, 02:01
by Jamestj
I have a roll of polypropylene plastic sheet bought from an office supplies shop. It is clear and shiney and about 10 microns thick.

Is polypropylene suitable for making IOM sails?

If I stick numbers on the sails they will show through mirror image. Is this acceptable?

The sails may be very difficult to see at a distance. Can this cause problems?

Is a glossy finish to sails as good as a mat finish?

Would transparent polypropylene be attacked by UV from the sun?

Whilst very strong in tension, a small nick causes it to tear quite easily. Is it strong enough?

Is this material available in different colours?

What is polypropylene sheet used for - has it got a more common name?


Thanks.

Posted: 14 Mar 2005, 04:14
by Arvin S.
Whilst very strong in tension, a small nick causes it to tear quite easily. Is it strong enough?
That is probably why it is not used for RC sails. Actually in my opinion it should be easy for you to purchase mylar drafting film instead, it should be readily available plus you will be using "tested" sail material.

Remember in big fleet racing small nicks on your sails can easily happen when booms hit your sails in close encounters.

Posted: 14 Mar 2005, 08:53
by ptercinet
Hi,

I think that a polypropylen film is well too elastic, only a polyester film will give you a sufficient dimensional stability.
some germans skippers use crystal flower film with some success...
but I dont know wich type of material is it (PP,PE,PET).

Pierre

Posted: 14 Mar 2005, 10:01
by Olivier Cohen
ptercinet wrote:Hi,

I think that a polypropylen film is well too elastic, only a polyester film will give you a sufficient dimensional stability.
some germans skippers use crystal flower film with some success...
but I dont know wich type of material is it (PP,PE,PET).

Pierre
Crystal flower film is made of PP.

I use it myself, and it is strong enough for A sails.

Posted: 19 Mar 2005, 01:09
by Jamestj
Many help for the info.

Could anyone tell me where I could get some tiny grommets to put in the luf to prevent the material from tearing? I live in England so the company would have to do mail order.
I have tried melting holes in the material but it does not work too well.

Sail 'Grommets'

Posted: 19 Mar 2005, 05:10
by Ralph Knowles
Try www.sailsetc.com and click Products then Sails then Materials, and at item No 78 you will find 'Eyelets' and 'washers' at £1.50 or so per packet of 100 pieces. You will also have to buy a small punch and die to fix them. Find the phone number and give Lorna or Chris a call. They will gladly help I am sure. Send a stamped and addressed A5 envelope and they will forward a free catalogue by return.

Cheers

Ralph

Posted: 21 Mar 2005, 08:19
by Jamestj
Thanks for that info, Ralph. Buying from a source specialising in IOM products means that they will be tried and tested in this application and won't rust or do other unpleasant things.

Can anyone help me with another problem I am having please?
I made a sail out of some drafting film. It looks OK until I try to make it take on the shape it would take if the wind was blowing from the opposite side. It sort of creases up and looks horible and obviously would not work if fitted on a boat.

I know that I am taking a liberty asking questions on this forum since I learnt elsewhere on this forum that it is suppose to be for members with boats already - so I guess some of the questions I have asked are rather dumb. However this is a schools project and it is best that I don't cheat and just copy other peoples ideas. However a sail if made concave it might 'snap' from one shape to another and this is clearly happening to my 'design'.

Obviously I have done something wrong. I thought that sails should have a double curvature, hence the need for seams. There is probably a very simple answer to my problem. Can anyone help please?