Mark wrote Graham, I guess you were using the very soft thin type. Yes, after looking at the video Jab has just posted, I see now that you are correct.

I could find only one company in New Zealand who would sell Tyvek by the metre and it was very soft and beautifully light. I did not realise the construction cover material (as we see in the video that Jan just posted) was somewhat much stiffer and heavier.

Graham, I guess you were using the very soft thin type.

The generic product I have used is for roofs, under slates / tiles.  Thicker and stronger as it has to resist wind loads. It is quite stiff and easy to sew.  (I used it to make a sleeping bag cover)

Anonymous wrote:

A couple of thoughts.

Here in UK, Tyvek type material is now always used under roof slates / tiles.  There are other brands less expensive. 
i would have though sewing is no more time consuming to glueing, especially if Arne easy methods are used. And it saves the cost of glue.

Bonjour

In France Tyvex is also used to cover building scaffolding and support some advertisements during the refit of the building. Some are exposed to wind, sun and moon for many month and sometimes more than a year. 

They are industrially welded in flat seems in huge panels that are attached to the scaffolding by rope lashings. (I'm thinking of one "place de la Concorde" on the "Hotel de la marine" that stayed there for very long time. Mainly one third of the width of the place de la Concorde and something like 6 or 7 floors high).

I've never seen any torn away. Sometimes, workers are opening some "windows" in the panel without any issue. 

I've only done some flat seems often double sewing, as I decided to have some vertical seems. The support of the wishbones where sewn to double the thickness and then sewn horizontally to the skin.

At start, I only sew because I hadn't found the proper glue. Then I glue and sew until I've made the traction tests. Then I just glued. It's much longer to sew than to glue.

The glue I used is just a soft film of glue without any support. It is placed on one the upper side of the under panel with the protection paper in place. The upper panel is then placed above and the protective paper ribbon is taken out by pulling it horizontally sideway while you press on the seem, just behind, to glue the two panels together. After, I press the firmly the joint by sliding my hand on it to crush the glue. I could have used the small roller than is used to crush the joints on wall paper. It is formally the same process, and as fast, as to close a pre-glued enveloppe.

I left the wingsail unprotected for about a month late spring in Britanny. When I dismantled it, I was surprised to see that the white "gaffer tape" that I used to fix the skin on the yard (just to have an aerodynamic shape - no significant effort) was rotted by the UV but the Tyvex was like new. 

I'll reuse the skin for the next prototype (different wishbones and sheeting system) hopefully next year.

Eric ( on a road trip in western Australia)

Mark writes:  would have though sewing is no more time consuming to glueing, especially if Arne easy methods are used.

It's not that easy to sew, I found. My first sail had a couple of tyvek panels, just as an experiement. It is extremely light and soft, and it is not a woven fabric. A more experienced person might be able to get things adjusted right, but I was a beginner and found it troublesome, compared with polyester cloth. I would be interested in Eric's response to that. I thought of using glue, at the time - even the double sided tape - but I never did, so I can't comment on that.

I thought it was very interesting material, possibly with potential, but I don't think I will be using it again. Also, I swapped the tyvec panels out after a few months, so I can't comment on durability, but I suspect it will not be very durable. Again, I await Eric's comments with interest.

(You have to be really careful with the hot knife on that stuff too. It melts and disppears in an instant the moment you put a hot knife near it).

A couple of thoughts.

Here in UK, Tyvek type material is now always used under roof slates / tiles.  There are other brands less expensive. 
i would have though sewing is no more time consuming to glueing, especially if Arne easy methods are used. And it saves the cost of glue.