UV-Resistant Thread for Boat Canvas

[Dockhead]

I have a cockpit enclosure and sprayhood which are in remarkably good condition for being 12 odd years old.

The only problem with them is that the thread which was used to sew the zippers in is disintegrating. Interestingly, the thread which was used to sew the enclosure and sprayhood together is fine.

I assume that the former is some kind of ordinary thread, and the latter must be something UV resistant.

As soon as I find someone with here (I'm in the Baltic) with a sewing machine, the next question will be what thread to use to sew my zippers in. Anyone have any tips?

[Maine Sail]

Originally Posted by Dockhead

I have a cockpit enclosure and sprayhood which are in remarkably good condition for being 12 odd years old.

The only problem with them is that the thread which was used to sew the zippers in is disintegrating. Interestingly, the thread which was used to sew the enclosure and sprayhood together is fine.

I assume that the former is some kind of ordinary thread, and the latter must be something UV resistant.

As soon as I find someone with here (I'm in the Baltic) with a sewing machine, the next question will be what thread to use to sew my zippers in. Anyone have any tips?

I have been specifying Gore Tenara on my canvas since it came out. It out lasts the zippers, canvas and windows.... Some canvas guys up charge on labor as it is a bear to work with...

[Seaworthy Lass]

I use Tenara. It has a high UV resistance (100+ year life quoted).

The strength is marginally worse compared to Dacron of the same thickness when new, but exceeds it within a matter of weeks (or it may be months, but a very short time from memory) with sun exposure.

Edited to add: it comes in two thicknesses. I used the thicker (could be V138) for the boom tent and the thinner (could be V92) for the cockpit cushions.
Helios is the other PTFE alternative.

If PTFE thread is not available, I would probably go for a well known brand of Dacron like Coats Dacron (someone may be able to recommend something better). In this case I would make sure V138 was used. I noticed a dramatic difference in deterioration of the thread on our old sacrificial strips between the thicker and thinner thread the sailmaker had used.

[Jim Cate]

Yep, Tenara is the good stuff. Our boom bag, nine years old, has not a stitch missing. Our dodger, about 5 years old had one zipper sewn in with Dacron by mistake. That zip was falling out... all the other seams are as new.

It does require some fooling about with the tensions to get the stitching right. The stuff is very slippery! But I think the reason for the raised prices for using it is simply that the thread is pretty expensive compared to even good Dacron. Here in Oz it fetches around 175 bucks a spool! But worth it!

Cheers,

Jim

[Seaworthy Lass]

Originally Posted by Jim Cate

Yep, Tenara is the good stuff. Our boom bag, nine years old, has not a stitch missing. Our dodger, about 5 years old had one zipper sewn in with Dacron by mistake. That zip was falling out... all the other seams are as new.

It does require some fooling about with the tensions to get the stitching right. The stuff is very slippery! But I think the reason for the raised prices for using it is simply that the thread is pretty expensive compared to even good Dacron. Here in Oz it fetches around 175 bucks a spool! But worth it!

Cheers,

Jim

It is very difficult to source here in Europe on the internet. After no replies to several queries I contacted Gore in Germany directly. I heard from the Greek distributor within a matter of hours and received a courier delivery within 3 days. That was about 4 years ago.

At the beginning of the year while I was in Australia I ordered some online from Sailrite in the US. It was $129 a spool. My spool from 4 years ago is only about half used.

It is worth every penny and more if you consider the cost of whatever you are having done and all the trouble (and cost) of taking it to a sailmaker/canvas worker and having it repaired only a few years later (the last stitching on the old boom rent lasted only 6 years).

For anyone sewing with it, don't be put off hearing it is difficult to work with. There are a few very simple tips Sailrite give and as long as these are followed and tension adjusted before you start, it sews very easily.

[poiu]

Coats Helios P is what I specified. The same as Gore Tenara essentially, but a little easier to get in Europe. Is the way to go as thread is the weak link.

[Free Spirit HC33]

At my shop, we sew all new canvas with the lighter weight Tenara, but if we're using Makrolon then we use the heavy Tenara. The best tip I got for adjusting tension is the following: sew about 4" in several layers of Sunbrella, remove the stitching (keeping track of top thread vs bobbin) and lay the threads side by side, adjust your tensions until the lengths of both threads are the same.

[Seaworthy Lass]

Originally Posted by Free Spirit HC33

At my shop, we sew all new canvas with the lighter weight Tenara, but if we're using Makrolon then we use the heavy Tenara. The best tip I got for adjusting tension is the following: sew about 4" in several layers of Sunbrella, remove the stitching (keeping track of top thread vs bobbin) and lay the threads side by side, adjust your tensions until the lengths of both threads are the same.

Thanks for that tip. I never thought of that. I just go by looks alone ie when the threads on both sides look equally buried where they go through the fabric. I'll try it next time when I think the tension looks about right .