Material for cockpit cover

[stewartkinsman]

Material for cockpit cover - Leaks V Condensation.

Hi Andy,
I would not rule out condensation as a contributory cause. I have seen this before - especially bad where there is frost on the outside surface, or even just a cold outside temperature. Warm, moist air, convecting upwards, from inside the boat also adds to the problem, as it condenses on the first available cold surface.
I would welcome an update on your third cover after a night of frost (we shouldn`t have to wait too long!)

 

[Eric S]

If you want to make a cockpit enclosure or tent yourself, I found a real keen priced site for buying the appropiate canvas: Esvo Campingshop in Holland.


Esvo has two main suppliers for cockpit canvas: Markilux and Ten Cate.
I think that Markilux / Sunbrella are the best canvas types for your cockpit.
P.S. they also have YouTube-movies how to sew or stitch your canvas.

Information from them:

Markilux is the guarantee for high quality boat canvas or synthetic boat fabric. Markilux is the classic boat canvas trademark on the European maritime market. The one-sided special poly-urethan coating guarantees an extremely high ‘water column’(=waterproof grade). Markilux boat canvas stands for the highest achievable technical characteristics and an exceptional shape retention(= a perfect fit).

Characteristics boat canvas. Markilux.
- absolutely waterproof. Incomparable waterproofness
- weatherresistant, mildew resistant, insectproof
- highest colour fastness. Optimal u.v.-protection
- AAA-shape retention and tensile strength
- Specially treated for dirt-, grease- and oil repellency.

This most sustainable boat canvas is available in a width of 140cm and in various colours.
P.S. If you need ordinary boat convas for covering purposes, we also recommend the boat canvas of Ten Cate. One of boat fabrics is Ten Cate All Season Touring (with different weights). Look further in our range or otherwise

 

[andygc]

Hi Andy,
I would not rule out condensation as a contributory cause. I have seen this before - especially bad where there is frost on the outside surface, or even just a cold outside temperature. Warm, moist air, convecting upwards, from inside the boat also adds to the problem, as it condenses on the first available cold surface.
I would welcome an update on your third cover after a night of frost (we shouldn`t have to wait too long!)

Sorry, I didn't see this. We're now into our third winter with the cover, with snow and ice. We've had no problems at all. Yes, we do get a little condensation sometimes, but what there is runs down the cover and over the side. We've never had any rainfall inside the cover like we had with the Weathermax. It has, of course been pouring rain over the last few weeks, and we've had waves over the pontoons, but the boat has stayed dry under the cover.

 

[nigelmercier]

It would appear that Weathermax is not such great stuff after all. Lovely to handle, lovely to sew, breathable, but completely useless as a waterproof winter cover for a wooden boat...

Sounds just like what I need, I particularly don't want waterproof. Are you dumping the old cover?

 

[KellysEye]

>Sunbrella is probably the best of the Acrylic canvas options

It is the best and longest lasting canvas, use Dabond UV resistant thread.

 

[oldbilbo]

I'm thinking of making up a cockpit cover for the Settimo Velo (http://www.facebook.com/group.php?gid=179427293999) I'm restoring.

I was wondering if there were any alternatives / recommendations from the Forum, and if anyone could recommend a supplier of material?

I have had several canopies produced for me by Attwoolls Manufacturing, who are just off the A38 a couple of miles south of Gloucester. They produce a very wide range of artic lorry trailer curtains, marquees, trailer and tonneau covers.... and much else besides.... in a range of tough fabrics. See their Made to Measure Portfolio: http://www.attwoollsmanufacturing.co.uk/

Their prices are rather less than the usual 'yottie' suppliers.....

 

[PetiteFleur]

>Sunbrella is probably the best of the Acrylic canvas options

It is the best and longest lasting canvas, use Dabond UV resistant thread.

I used acrylic coated canvas for both my sprayhood and cockpit cover. Even though I used UV Resistant thread, I've had to resew the sprayhood this winter, all the thread was rotten but the cover is now 8 years old.
All bought from Kayospruce, excellent company to deal with.

 

[TimBennet]

Weathermax isn't breathable in the sense that air and moisture will pass freely through it at will.
It is a semi-permeable membrane and all the problems with its use in boat covers are the same as were experienced when Goretex first hit the mountaineering world 30 years ago and people thought it would be ideal to make tents from it.

For water vapour to pass through a semi permeable membrane, you need a 'driving head', the most effective of which is a higher temperature one side than the other. With Goretex clothing, it's the body's temperature that provides the energy needed to 'push' the water vapour through the membrane from inside to out. But on a boat cover it's entirely possible in the early morning, or when the sun comes out from behind a cloud, that the temperature on the outside of the cloth may in fact be higher than that on the inside. Especially when the material is dark in colour and quickly warms. When the temp is warmer on the outside, the moisture will be 'pushed' from the outside to the inside.

You won't see any tents made from goretex these days (with the exception of specialist, very high altitude assault tents) as the air volume inside is impossible to keep warmer than the outside in any meaning, practical way. You won't see boat covers made of Weathermax either in a few years.

Cotton Canvas is permeable.
Weathermax is semi-permeable
Sunbrella and other acrylic canvases are impermeable.

 

[MiracleMaud]

Sorry, I didn't see this. We're now into our third winter with the cover, with snow and ice. We've had no problems at all. Yes, we do get a little condensation sometimes, but what there is runs down the cover and over the side. We've never had any rainfall inside the cover like we had with the Weathermax. It has, of course been pouring rain over the last few weeks, and we've had waves over the pontoons, but the boat has stayed dry under the cover.

Andy - Can you recall which variant of the Weathermax fabric your cover was Andy? I'm considering Weathermax fabric, along with a couple of others for a new sun awning. Obviously there will be excellent airflow around the awning, but it'll be up in the rain too.

Thanks, in anticipation.