Tenara Outdoor Marine Thread

Tenara Outdoor Marine Thread

After hundreds of hours researching marine canvas materials and hardware we are not yet ready to announce the best canvas, but we have chosen the best thread…. Tenara . Made by Gore-Tex, Tenara thread is available in many fade-proof colors from retailers online.

Readers of The Teak Rail demand the best products and material from suppliers and, while some choices are clear, others remain a little muddy. Apart from well varnished teak, regular scrub-downs and a shiny top coat the item that aesthetically seperates a well cared for yacht from the rest is the canvas. From the bimini or doger to the helm cover, well canvased boats have the finished look we appreciate while protecting vulnerable components from the elements.  Canvas can also be the most difficult to maintain.

So what makes a canvas cover look great?  The most important feature is material. Canvas is an extremely heavy-duty plain-woven fabric used for making, tents, marquees, backpacks, and other items for which sturdiness is required. Modern canvas is usually made of synthetic material, although historically it was made from hemp. It differs from other heavy cotton fabrics, such as denim, in being plain weave rather than twill weave and repels water rather than absorbing it. Canvas comes in two basic types: plain and duck. The threads in the higher quality duck canvas are more tightly woven. The term duck comes from the Dutch word for cloth, doek.

In addition to being titghly woven, water repellant and durable the best marine canvases contain bright colors that are highly resistant to UV fading.

We are currently testing products in our search for the best marine canvas material and choosing a favorite (Sunbrella Fabric is the current leader) but our research has uncovered a secret that, frankly, has suppressed us.

After talking with canvas makers and conducting over a 100 hours of research we found a second factor essential to both the look and durability of your canvas covers… fit and finish. The best looking covers are form fitting and maintain their form throughout the life of the product. Proper fitting and hardware also prevents the wind from blowing rain underneath the cover and prevents it from blowing off entirely.

A Note On Craftsmanship

The most important factor for obtaining a glove-like fit is craftsmanship. Well fitted canvas needs to be tailor made for your boat. This limits owners of custom yachts to local canvas shops within driving distance of a shop that’s willing to travel to your boat to make custom measurements. Owners of production boats have more options. Modern software allows the best canvas shops to download drawings of your vessel, making glove-fitting canvas covers available via the mail. Marine retailers like West Marine offer covers for the most common components (e.g. outboard motor, BBQ and winch covers) and the fit is good but the finish is only available in a few standard colors like black and the ubiquitous (and awful) “marine blue”.

Well appointed vessels have canvas in colors that match the topcoat and all covers on the best looking boats are made from matching fabric. For this reason, we suggest forgoing retailers and getting custom canvas. A second option is a large canvas shop willing to ship worldwide. We suggest forgoing this option too because, when ordering custom canvas over the phone, it’s important that you talk with the canvas maker directly, and not a phone representative working for minimum wage.

In short, the first step to getting great canvas is finding and working with quality craftsmen. Our suggestion is to find a canvas maker close to you by visiting the docks, finding the best examples of canvas work and asking the owners who performed the work. If, however, you live in a remote area or in a place where the local canvas shops perform sub-par work we suggest finding small, high quality, shops willing to deliver. Practical Sailor has a list of recommended sailmakers on their website but not all do canvas work. One shop from the list we can recommend is SLO Sail and Canvas in San Luis Obipso California. This was one of the shops we visited in researching the topic and found their fit, finish and materials to be A++.


Accurate measurements and selecting quality fabric are only the first step in ensure a perfect fit. Each item will need to be tied, snapped or otherwise affixed to your boat and this requires the use of quality fastening hardware.

Nothing makes a canvas cover look worse than a long curving trails of rust stain. For this reason we suggest using only the highest quality 316 Stainless fasteners for your marine canvas. Durable and rust-proof 316 stainless will outlast the fabric and material and require little maintenance apart from washing off salt deposits. Unless you have the budget for titanium fasteners, 316 is the best way to go.


Before the invention of uber-durable synthetic materials, the lifespan of your covers was determined by the lifespan of the fabric. This is no longer the case. Quality marine fabrics like Sunbrella can still look great 5-10 years after purchase but few covers last this long. Why? The answer is thread.

In talking with dozens of experts, apart from the fabric itself, the most important feature in all sewn materials is the thread. Thread binds the seams and ensures that the carefully measured, form fitting, canvas you order does not pull apart at the seems. Most canvas products today are Polyester thread which is very durable, long lasting, material when threads are combined to make large diameter rope, but, when stretched thin, looped and sewn through fabrics has a lifespan of only 3-5 years.

According to one sailmaker we interviewed “the single most common problem we see in our canvas repair shop is polyester thread failure. Vessel owners simply don’t know enough about canvas work to request Tenara thread, and canvas shops are unlikely to recommend it because it is significantly more expensive.” How expensive? A single spool of Tenara costs more than $100!

Is the high price of Tenara worth the expense? Yes!

Polyester is simply not UV resistant and durable enough to outlast the modern marine fabric. Thread is used sparingly, to prevent puckering, canvas is sewn with low stick counts. Combined with the fact that fabric and time constitute the majority of a new cover’s cost…. using Tenara is a wise choice for all but the most budget conscious and handy (you will be doing many repairs with polyester) boaters.

What makes Tenara so good?

Tenara is made by GoreTex and comes with a Lifetime Guaranteed. It is available in a wide range of colors and is constructed of fluoropolymer fibers that have the high strength and durability to last over ten years. Tenara is also highly resistant to UV rays, cleaning agents, pollution, saltwater, air, rain, and snow.

Tenara also remains colorfast even in extreme temperatures and frost. Tenara also sews very well and does not require as much upper tension as normal polyester thread, translating into a better fit and finish.

How do we know it will outlast all competition? GORE has made public the results of extensive tests performed in full Arizona desert sun showing that TENARA Outdoor Thread retains its strength for over five years in the most UV prone environments. During the same experiment (same duration and conditions), both polyester and cotton thread lost over 80% of their strength but Tenra did not fade, discolor, and weaken over time.

TENARA thread is also hydrophobic, meaning it repels water. Without water, micro-organisms like mold and mildew will not grow in the thread. Both polyester and cotton threads attract and retain water to absorb color, but it also makes for a very attractive environment for mold, mildew, and algae. Over time, the natural progression of mold and mildew can cause outdoor thread to rot, discolor, and lose integrity.


High quality canvas covering is essential to the longevity of sensitive components (e.g. winches, outboard motors, sails, etc) and a major factor in the esthetic appearance of your yacht and the most critical component of that canvas, apart from the fabric itself, is the thread.

For this reason, Tenara Outdoor Thread is the best thread for new canvas work (and repairs!) on the market today.

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