Marine Thread: The “Glue” That Holds it All Together

Marine thread is the glue of boat canvas. Be sure you know the basics. After fabric, it is the most important component of your boat canvas.

Many boaters believe that marine thread should last forever. After all, it's outdoor thread, right? Well, there actually is one type of outdoor thread that does last forever. It is thread made with PTFE or Polytetrafluoroethylene, which is really Teflon®. This type of thread can be exposed to sun, salt, chemicals, pollution, it doesn't matter. It will last and last.

Gortex is associated with the brand name Tenara®, the first PTFE thread of its kind to hit the market. In the beginning it was a flat fiber that most sewing machines could not accommodate. Over the years they modified their process and came out with a twist thread that could be used with any sewing machine. Colors include, black, white and clear.

The reason you don't see PTFE threads being used in all marine canvas shops is the price. At $200 per 1-pound spool, it's simply beyond the reach of many fabricators to add it to their inventory. Besides Tenara's gortex, Solarfix® has made a big competitive splash in the market.

Thanks to PTFE thread, canvas boat covers can finally be made with the quality they deserve. It's the only marine thread that will literally last forever is PTFE thread

So what about the rest of the outdoor threads on the market?

Polyester or polyester dacron is the most common marine thread you will find in canvas shops. They are UV bonded and most are anti-wick which means that as the thread gets wet it expands in the needle hole helping to keep the water from seeping through. These threads are considered chemical and heat resistant.

The two common sizes used are 92 and 138. Having used both, I can speak from experience and say without a doubt that 138 will outlast 92. So if you have a choice, go with the heavier thread.

Some marine thread brand names used on boat covers include the following:

  • Sunguard
  • Sunstop
  • Star Ultra Dee
  • Aqualon
  • Dabond

All of the above, except PTFE, come in many colors. For the DIY stitcher ready to sew your own project, you can buy the small size 92 in 4oz spools. Your home sewing machine should be able to sew with 92, but very unlikley that you can sew with the 138.

The next size down from size 92, is 69 and your home sewing machine will definately be able to sew with it, but it won't hold up in the sun. In the south you would be lucky to get a year out of size 69. If you use this size, plan on frequent restitching.

Marine Thread

Polyester Marine Thread

Buy Marine Thread Here

Available in 92 Black and White - 4 oz spool

We are proud to offer lifetime Solar Thread - Although we can't guarantee this thread will sew on your home sewing machine, it does sew nicely on my early model Kenmore and our industrial machine. Black coming soon!

Solar Thread

Lifetime Solar Thread

Thread cone holder

Thread Cone Holder


Black $18.99
White $16.99
Solar White 2oz. spool 35.00
Thread cone holder 7.99


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Lastly, I will mention what NOT to use!

Nylon thread. Nylon is a bad choice for outdoor thread. Be careful when you have your custom cover made. Be sure to ask what type of thread they will be using. We restitch plenty of covers that have been sewn with nylon. This happens frequently with auto trim shops and home furniture upholstery shops. Sometimes they just don't know any better. For more on canvas boat cover repair check out our webpage all about boat cover repair.

To sum up this discussion on marine thread: If you can have your cover stitched in Tenara (Gortex thread) or Solarfix thread, do it. You won't be sorry!

Please be sure to check out our EZ-Xtend boat zipper repair products while you are here.

EZ-Xtend Boat Zippers
EZ-Align Boat Zipper
EZ-Xtend Boat Track
EZ-Xtend Drip Shields

Return from Marine thread back to the Canvas Boat Cover and Repair Advisor!

EZ-Xtend Boat Zippers donates 10% of proceeds of this website to

Eagle Ranch

A Christian based children's home for boys and girls in crisis and in need of hope and healing.


Fantastic Results

"I wanted to thank you for the fantastic results I have with the EZ-Xtend zipper solution you provided for my Sea Ray.

The isinglass had shrunk to the point that installing it was an all-morning job, with some snaps totally unusable due to the material shrinkage. I really was preparing to purchase a complete new canvas set, but hated to spend the money-especially since the canvas is still in excellent shape.

The EZ-Xtend zippers have made the canvas/isinglass installation and removal about a 10 minute job! (and looks great too!) Thanks again for the quick solution and the reasonable cost, I really do appreciate it."
Steve Donovan

The Bottom Line

The extend zippers have been a resounding success. Zippers were needed for the starboard stern section of my bimini top, and for both side curtains of my camper canvas. It is a clever design you came up with to increase the width of connectivity between my bimini top and camper canvas sections. I do not know what I would have done otherwise as the camper canvas sections have shown shrinkage over time.
M. Marien

Such a Great Idea

I got a chance to install these yesterday and just thought I'd get back to you to let you know that they worked perfectly for me. I couldn't be happier with that simple to install solution to my problem now allowing me to properly and fully enclose my cockpit again. Such a great idea.
J. Reed
British Columbia

Easy to Install

The Ez-xtend zippers were very easy to install---especially with a little lubricant ( which I always apply periodically to zippers)
New Jersey

Rare Traits

"True skill and craftsmanship are rare traits in today's society. When they're held by a person that truly cares about her customers, brings honesty, creativity and passion to her work, you have just described Tammy Hampton. Better known as "The Cover Girl," Tammy has been both a friend, mentor and business partner for nearly twenty years.

I found Tammy by her name tag.... sewn to a sailboat cover, in a nearby marina. The boat cover was fitted with such precision, it clearly stood out from the others. In the years since, Tammy has 'dressed out' at least twenty boats for me. She has yet to meet a challenge for which she could not find a creative and effective solution.

Tammy has become a valuable resource to my BoatButler business, and she has actually created sort of a "cult" following among my customers. Once they see the quality of her work, the choice is an easy one.

I am still grateful for that little tag on that sailboat cover I found nearly twenty years ago."

Steve Hammond
Owner, Boatbutler Marine Services, Inc.
Alpharetta, Georgia

Love Your Website

I love your website and wish we lived closer, so that I could stop by your shop - sounds like a wonderful place!
Judy D
Winchester, TN

Thanks for the education

Thanks so much for the education I received from your site! I have been in to two local shops for estimates on a new canvas enclosure for my little boat. Both commented that they were happy to have a customer who knew what he wanted and was familiar with the material and options available. I learned it all from you!!
Alan S.
Arlington, WA

Zippers solved a major canvas issue!

With your zippers in place we could button up all of the canvas and make a very nice weather tight space which made our boating season very enjoyable.

Excellent customer service!

We finally got the chance to install of the ez-xtend zippers on our enclosure. (in between numerous Florida rain showers). and it turned out great! Everything finally fits together and it keeps the rain and the bugs out. Yay!
I will be sharing your zipper solution with other boating friends and will be sure to mention the excellent customer service too.

Great Website!

Looking forward to getting these items as it will save me a $3000 boat top replacement. Great website and sure glad someone thought to make these items up.
Lake City, MN

Boot looks and fits great!

Received the boot, it looks and fits great! Thanks for the fine craftsmanship, communications and speedy service.