Winshield Cover Options

Recently there was a good thread on Pfifertex windshield covers: http://www.trawlerforum.com/forums/newreply.php?do=postreply&t=45532

We need to replace our windshield cover and are looking to improve how well it blocks heat. The current cover is navy blue Sunbrella and in the direct sun, it actually makes the cabin hotter. The windshield radiates substantial heat that you can feel when you get close to it, often making it uncomfortable in the cabin, even at the dock with the AC running.

This seems to be the opposite of what I have seen in other threads, where darker colors have been good at reducing heat transmitted through the glass.

I have been thinking white Stamoid would be a good choice, but the discussion I linked to leads me to wonder if Pfifertex would be a better choice. I think the boat looks better with a dark cover, but anything that will cut down on cabin temperature is preferable.

Your thoughts on fabric choice and color would be most helpful, as I have not been reaching any conclusions on my own.

This photo was taken when the boat was facing away from the sun, so it was hitting the Sunbrella at a pretty big angle!

I personally would go with white Stamoid for that application. White will reflect the heat best. If seeing out is a concern then go with a Pfifertex type material. I have a Cadet Gray Sunbrella bra on my boat and it reflects heat well but not as good as white will. If you are going white then Stamoid is the way to go since it will stay clean. White Sunbrella will be difficult to keep clean due to its woven fabric will hold dirt in the pores. Stamoid is smooth so it won’t trap dirt.

As Dave mentioned above, Pfifertex is great in that it allows you to see outside the boat. Not well enough for while underway, but it sure is nice to not feel locked inside.


My wife decided ours needed to be black for aesthetics. So of course we have black. I would have preferred a lighter color the black Pfifertex really does keep our pilothouse a LOT cooler than it was before we installed them.



Yes, you get heat radiating from your windows when they are covered, but that is likely much less total heat inside the boat compared to if the suns IR energy was being absorbed inside the boat. Consider that the fabric is radiating the heat both inside and outside the boat. If that IR energy is absorbed inside the boat, all if it will be radiated inside. Sure, a lighter color will be cooler than the darker color.

dhays said:

Yes, you get heat radiating from your windows when they are covered, but that is likely much less total heat inside the boat compared to if the suns IR energy was being absorbed inside the boat. Consider that the fabric is radiating the heat both inside and outside the boat. If that IR energy is absorbed inside the boat, all if it will be radiated inside. Sure, a lighter color will be cooler than the darker color.

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As an engineer, I agree with how you are looking at this, but it seems that the boat is cooler if we remove the windshield cover. My only thought on this is that perhaps the area under the windshield is off-white gelcoat and it is reflecting the energy back out the windshield. Does this make sense to anybody else?

No, once the heat is inside the windshield most of it won’t reflect back out. Some of the energy may reflect back out but some of it will stay inside. Best way is to keep it out in the first place. If it were me and heat gain is your major concern, then a white Stamoid bra with maybe some thin foam insulation between the Stamoid and the windshield. Just make sure it is closed cell insulation so it won’t absorb water.

Also have the fabricator use Tenara thread. It is guaranteed to last as long as the fabric. As opposed to poly thread that does not last very well.

For decades the RV folks have been able to see outside and leave the heat and UV outside .

Custom covers can be made by many companies and cost little more than stock covers.

https://www.shadepro.net/product/rv-windshield-covers/

We have white Sunbrella covers for our windshield and I can tell you they really stop the heat from coming in.

Ken

Waywego said:

We need to replace our windshield cover and are looking to improve how well it blocks heat. The current cover is navy blue Sunbrella and in the direct sun, it actually makes the cabin hotter. The windshield radiates substantial heat that you can feel when you get close to it, often making it uncomfortable in the cabin, even at the dock with the AC running.

I have been thinking white Stamoid would be a good choice, but the discussion I linked to leads me to wonder if Pfifertex would be a better choice. I think the boat looks better with a dark cover, but anything that will cut down on cabin temperature is preferable.

Click to expand...

Our original windshield cover was (is) white Stamoid. We still use that for winter lay-up, but or normal cover now is black mesh Textilene... which I think it similar to Pfifertex?

Anyway, I don't notice any significant difference in heat in the saloon... and we only put the black cover on during our hottest months... so we can see thru it when the cover is on, but we can see out even better with no cover at all.

I haven't measured for any differences, though...

And our windshield tinting (whatever it is) may be a factor in play, too...

-Chris

Thanks for all the advice!

Chris, I am particularly interested in your experiences since we are close to you geographically. If I read your comments correctly, you do not see much temperature difference between the white Stamoid and black Textilene. Is that correct?

Our boat faces north in our slip, so you would think that with a windshield slanted almost 45 degrees, the sun would be at such an acute angle that this would not be a problem! Our windows are tinted, though the tint is getting old and I might remove it or replace it.

Since my wife can sew up a new cover and we have a good pattern with the existing one, the cost of the material is not that big of a deal. And yes, we will be using Tenara thread, though we sometimes use UV resistant polyester thread for repairs of old canvas when we know it will only last a few years.

Waywego said:

Chris, I am particularly interested in your experiences since we are close to you geographically. If I read your comments correctly, you do not see much temperature difference between the white Stamoid and black Textilene. Is that correct?

Our boat faces north in our slip, so you would think that with a windshield slanted almost 45 degrees, the sun would be at such an acute angle that this would not be a problem!

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Correct. Although I haven't tried a thermometer reading on anything, so my impressions are very subjective.

We face north, too.

And we usually leave the covers off during March-June and again from September-November... or longer if we're onboard over the winter. That's mostly because we prefer the view, rather than felling cooped up. Otherwise, we just put the white Stamoid cover on for winter out of habit I guess...

-Chris

Waywego said:

Recently there was a good thread on Pfifertex windshield covers: http://www.trawlerforum.com/forums/newreply.php?do=postreply&t=45532

We need to replace our windshield cover and are looking to improve how well it blocks heat. The current cover is navy blue Sunbrella and in the direct sun, it actually makes the cabin hotter. The windshield radiates substantial heat that you can feel when you get close to it, often making it uncomfortable in the cabin, even at the dock with the AC running.

This seems to be the opposite of what I have seen in other threads, where darker colors have been good at reducing heat transmitted through the glass.

I have been thinking white Stamoid would be a good choice, but the discussion I linked to leads me to wonder if Pfifertex would be a better choice. I think the boat looks better with a dark cover, but anything that will cut down on cabin temperature is preferable.

Your thoughts on fabric choice and color would be most helpful, as I have not been reaching any conclusions on my own.

This photo was taken when the boat was facing away from the sun, so it was hitting the Sunbrella at a pretty big angle!

Click to expand...

I'm not sure what variation of Sunbrella is on your boat but it doesn't breathe very well and traps heat. I've done shade cloths for boats out of Sunbrella and it will hold heat under the cloth if it's curved in a way to form a bubble, of sorts Like a bimini. So I can imagine it would act in a similar way against a windshield trapping heat in the void if there's one.


I can't recommend a product but anything light in color with perforations to allow heat to escape would be a great help. Tint gets mentioned and I will say this. Our Kia Soul came with Solarflex tint (I think that's the name). It's silver and has an all black interior with light gray accents. On a hot day, our Soul is cooler than my truck that sits in the shade and is all silver with light gray interior. The Soul has 35% on the two front doors. The back doors, sidelights, and hatch are all 50%. I can't see really well at night and I have no problems seeing with the tint.


The other option I mentioned in another thread is DIY upholstered Reflectix panels to cover the inside of the windows. They can be used like shades and work great when off the boat to keep out heat and prying eyes. There's lots of good videos with a lot of different options on youtube.