Geoff Schultz" geoff"at wrote:
We've been having problems with a new bimini which we had constructed
using Gortex (Tenara) thread and Sunbrella. The Ship's Tailor in
Deltaville, VA did the construction. We were very happy with the
fabrication, but all of the seams leaked with water droplets forming
at the needle holes. The fabricator utilized a #18 needle and after
the fact we did a huge amount of research and have been told that
they should have used a #16 needle. Based upon partial
deconstruction we saw that the fabricator sewed through the
seam-stick tape, as they should have.

We also utilized Sunbrella Supreme, which is a new fabric from
Sunbrella which is MUCH more water repellant than normal Sunbrella.
The fabric had flaws in it which didn't become apparent until we were
using it. Sunbrella was great and had a rep meet us in Annapolis to
look at the construction. Later we shipped the bimini to Glenn Raven
Mills (who makes Sunbrella) and they were absolutely great. They
said that the fabric was defective and should never had made it out
of the factory. They refunded the entire cost of having the bimini
constructed ($1700) and will provide the fabric for it to be
reconstructed. I love companies who stand behind their products!

Next hurricane season we're planning on returning to Deltaville and
have the Ship's Tailor re-make the bimini. Because BlueJacket spends
so much time in the Caribbean sun, normal thread just doesn't hold up
and we've spent lots of time resewing parts of it. The Gortex thread
should hold up much better, but we're concerned about utilizing
Gortex thread again.

Does anyone have positive experience with Gortex thread and Sunbrella
that they would be willing to share? Do you know what construction
techniques were used?

-- Geoff

Spent a lifetime in waterproof clothing fabrication, and I've never heard of
Goretex thread. The only way to really waterproof needle holes is to
heat-seal the seams with waterproof tape which is coated with the same
plastic coating as the main fabric is waterproofed with. This is applied
with a special machine with hot rollers and a hot air blower to melt the
tape, and usually lasts the life of the product. All this assumes that the
main fabric is coated on the back, i.e. the inside surface of the bimini.

If the coating is in the outside of the fabric, then the usual method is to
high-frequency weld the seam using an ultrasonic welder, hence no sewing,
although some firms do sew the seam first then strip-weld inside the sewing
line usuing the same ultrasonic welder.

Goretex do supply the tape for their own laminates, but this is another
world altogether.


Dennis.