Thermo-forming mylar sheets

Hi Guys,

I was just wondering if anybody has experimented with thermo-forming a sheet of mylar to create a sail with draft, in lieu of broad seaming? I can see multiple advantages of this method as it would not have seams to pull apart and the shape would be consistant from top to bottom.



if you can do it let me know!:graduate::smiley:

The idea occurred to me a while ago. I had thought of a foam aircraft wing with a balsa covering of the right section chordwise and bent spanwise to the correct curvature. The oversize Mylar (polyester) should then be layed over the mould, anchoring with adhesive tape to the luff and clew and either ironed or heated with hot air to take advantage of its heat-shrink properties to end up with a single panel 3D sail.
Aeromodellers routinely shrink films to much tighter curves on their models and I seem to remember some very fancy hardware being around to make full-size sails in a similar manner.

yeah, fullsize, like the North 3DL sails… good stuff. someone should try it:graduate:

I was thinking the mold would need a male and female side to press the mylar between and something to keep the corners tight.

I just thought this method may have trouble popping the sail to the other side in light air.


“Popping” should be easier as there’s no double thickness of the seams or sticky tape. If you think about film covered model planes, the female mould doesn’t seem necessary.
If I remember my calculations correctly (they involved trigonometry, so I’m not going to do them again:scared: ), the wing should be arced across the span by about 5º. and with the 15% chord section, the film should have no problem conforming.

Did you your sails this way???

I’m thinking about to do the same.