Experince Using Gortex Thread with Sunbrella

[geoffschultz]

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

[GordMay]

SunBrella fabric is not waterproof; it is water repellent, so you should occasionally retreat your SunBrella fabrics with a water repellent treatment, such as 303 High Tech Fabric Guard.
There are also numerous “Seam Sealer” products available.

[Greg S]

Geoff,

When we were asking around for someone to do our bimini and dodger the Ships Taylor came highly recommended from just about everyone, I wish we would have been able to use them! Not sure if this will be of consideration to you, but when we did our sunshades we were advised against using the Gortex as it will not stretch at the same rate as most other materials, thus it breaks instead. However the bimini shouldn't stretch that much, and it does last just about forever. As I recall, we were also told that the Gortex thread required a larger needle, and that there would be drips from the needle holes, but that as the material got dirty the thread holes would seal up.

Greg

[hellosailor]

Geoff-
The claims that Tenara will hold up in outdoor use echo the old claims for polyester or nylon thread when that "replaced" plain cotton. And I'd expect the same downside to it.
If the thread is stronger than the material it is used in, it will saw the material and enlarge the thread holes. If it is software, it will wear out first and need to be resewn. And, unless the thread neatly plugs the holes by some mechanical means, they will leak in the rain.

What used to be recommended was "DaCot" thread, dacron core with a cotton outer layer. The logic was that the Dacron had durability but the cotton will swell up when it gets wet, to help seal the holes when it rains. To me that logic still works, but even with camping gear it was never good enough--you have to use a seam sealant (used to be urethane, now some kind of water-based product) to seal the seams. Which is probably part of the reason GoreTex rainwear comes with seams that are TAPED and sealed after they are sewn. Needle holes are simply going to leak, sooner or later, no matter what you do.

I'd suggest letting the bimini company work with the materials they are used to and familiar with, if they are good folks they will have reasons to be working with those materials. If threads punking out in the sun are a big problem...seam sealant, UV protectant, or...maybe they can glue some type of "ribbon" over them, to really seal them just like GoreTex rainwear is sealed?

[Richhh]

There is a 'seam sealer' available from most 'mountain' shops that easily seals the tenara (and the goretex membrane when used).

Using a larger needle, especially with a 'ballpoint' end will stretch the hole and it (may) takes some time for the hole to 'work' back to 'closed'. Rubbing (aggressively but gently) the stitching/fabric will sometimes help the needle punches to close. For those sites that remain 'leakers' consider to use the 'seam sealer' (available in 'dispensing tubes'). an example of such 'seam sealers' is: http://www.seattlefabrics.com/Seam%20Sealers.htmln Just a teeny dab from 'underneath' is usually all thats required .. although most 'mountain climbing' shops usually carry various 'brands' of the stuff.

[Pblais]

If the thread is stronger than the material it is used in, it will saw the material and enlarge the thread holes. If it is software, it will wear out first and need to be re sewn. And, unless the thread neatly plugs the holes by some mechanical means, they will leak in the rain.

The Tenera thread will make a bigger hole and needs something to seal the holes. Silicone works just fine since the fabric is courser than nylon. You don't have to use a "special" sealer.

This is the downside but if you use any other thread you WILL be restitching it down the road well before the fabric is UV damaged to the point of needing replacement. The claim of Tenera lasting loner than the fabric is fact. The canvas I'm replacing now was restitched twice before the fabric finally died.

Given you are on the Chesapeake your restitch would be about 6 - 7 years. I restitched the last boat canvas and that was about how long it lasted. When it goes you can run your finger down the seam and open it up to the touch. The old fashioned "UV treated" thread won't last. What I replaced was Sunbrella thread.

When you use other thread the cotton component swells to help fill the hole and a little dirt does the job pretty well for the smaller hole. Tenera does use a larger needle so the problem is easily more noticeable and does not close up as Tenera does not swell or stretch. It's strong enough you can't break it with your bare hands easily - if at all. It won't "saw" it's way through if the canvas is sewn properly. It leaks because the hole is bigger and the thread does not swell.

I would use it on all the critical exposed seams and use the cheaper thread for areas that don't get much sun exposure. That's how I'm having it done right now. I also didn't use Sunbrella for the cockpit canvas. I'm using an off white Stamoid fabric. It does a tad better against UV. The light Sunbrella colors fade too quickly. Only the blue and greens hold up for very long.

You won't be able to use Goretex rainware tape. Actually Gortex is just the lamainate membrane component and the sealing tape adhears to the nylon cloth backing. It won't stick to Sunbrella. Garments are not made with Tenera thread. The sealing glue may work OK too but I think a clear silicon will work as well as reapply a lot easier. The seam sealer glue is made for dacron thread as it absorbs the sealer. I think it uses a toluene base (air plane glue). The tenera thread won't absorb anything.

[geoffschultz]

First off I would like to thank everyone for their replies. I appreciate all of the feedback.

I will point out that BlueJacket spends the vast majority of her time in the Caribbean. This is the first time in 7years that she's been back in the US for any length of time. We brought her back just to have the canvas work done. As a result our demands for canvas are vastly different than a boat in most of the US. When BlueJacket was in the New England area, I would never have worried about what I worry about now. The Caribbean sun is brutal and UV resistant V92 thread just doesn't hold up. I don't want to be re-stitching the bimini every 2 years as we had to do in the Caribbean.

I will also point out that Sunbrella Supreme is a completely different cloth when compared to normal Sunbrella. Sunbrella Supreme is water proof with hydro ratings near 1000 cm vs. hydro ratings of only the high 30's with normal Sunbrella. You don't have to re-coat with 303 type sprays (which are considered HAZMAT and you can't fly with those). We're using Linen colored Sunbrella and every sealer that we've tried leaves a visible mark. As Sue has said, it's like you applied clear nail polish. For dark fabrics I think that it would be fine.

I think that part of our problem is that we've having the work done in the Chesapeake and they don't have experience with these kind of products/problems. BlueJacket is in Ft. Lauderdale right now (awaiting our return in a few weeks), but our experience with the with fabricators there has been less than stellar. For one thing, I think that many of their local customers don't spend a lot of time on their boats (other than on the dock on nice weekends and thus don't ever really see how well the fabrication works) and their other customers are transient and this not around to complain if things go wrong. We fell into the later category one job.

The fabricator used triangular #18 needles and did their best to sew through the seam-stick tape. According to the folks who make Tenara, the seam-stick is a key thing. Perhaps the issue was the use of the #18 needles as compared to the suggested #16. I'm just leery of re-doing this job and having it leak again.

I am interested in how Pblais is sealing his Stamoid. Our experience is that once you put a hole in Staimoid, it's there. How are you sealing it?

-- Geoff

-- Geoff

[Rick]

Pay attention to Hellosailor's recommendation of a thread which may prove to be a great compromise in the use of combined synthetics.

In addition, beeswax bars rubbed across the threads and any zippers, etc. will vastly help in keeping drips from passing through when nasty storms force huge amounts of rain and green water over the whole thing.

When you are snug in such a container you will become very critical of each tiny hole that passes drops of water on you after doing everything correctly because normally there will be no water dropping on you inside.

I can't overstress what Hellosailor is talking about: cotton thread will work really well at not destroying that expensive synthetic Sombrella yet his suggestion will last MUCH longer without damage.

[senormechanico]

I'm an authorized Bernina sewing machine technician, and I doubt the small difference in needle size would make much difference in your case. Most people think a needle makes a hole in the fabric when in actuality it temporarily pushes the threads apart. That's why a ball point needle is used. If a needle actually pierced the threads of the fabric, it would start unraveling at each stitch hole before the project was even finished.

Leather or other similar non woven products require a sharp tipped needle to actually pierce the material.


Steve (spent today doing jib repair/maintainence with V69 thread) B.

[Pblais]

I think the choice is restitch every couple years in the tropics or deal with the holes. You can't use dacron thread and have it last. The fabric is a non issue as it will last longer than the thread - even to old style Sunbrella. Down in the teen lattitudes expect to restitch 3 times before you toss the whole mess out. With Tenera you can't seal the holes and not have it show. Pick your problem or move to lattitudes greater than 40 degrees. If you know you'll have to restich you can do it before you need to just because it is easier that way. I paid $1000 to restitch a full enclosure and sail covers and assorted door prizes on the last boat. That was to do every single seam again to be sure.

What you can do is in the production expose the seams as little as possible to minimize the seams that are exposed. That becomes a serious design issue and takes a lot of time and experience. It costs a lot more to do it that way. If they don't already know how they can't do it.

Given that I know the Ships Tailors reputation I can say is they are able to perform good work and have been around a long time. Around here they set the standard for the highest prices too. You'll find the canvas industry as a whole is a artisan trade. There just are too few folks that can do great sailboat dodgers, tops, and enclosures. More do the large powerboat enclosures because they pay more and are less tasking. The clients are also less picky. Having been through this twice I can honestly say I know less than I did before I started. Some things really are hard. There are a million tiny details and if done properly none of them show.

We are getting our work done down in Hampton. The folks there do a lot of work on sailboats and they own them as well. Jo said when she started doing dodgers they used to take 8 hours of labor. Now she says it takes 24 hours. There is just a lot more work when you have to bury seams and do things right so they will last. That said we have been well warned about the problems with using Tenera thread. She has sealed a few up too. Silicone seems to work as well as anything and it's easy to reapply and shows less than other materials.

There isn't a perfect solution other than a hard bimini / doger. A dodger with a full enclosure might run about $5,000. Makes you think maybe the hard top isn't such a bad deal.

[geoffschultz]

Thanks for all of the advice. I thought that people might enjoy seeing a web page from the people that make Tenara thread about the effects of UV on thread strength. I found it quite interesting:

Gore Fibers

-- Geoff