Literally everything melts here.

[Simi 60]

Loving the 700mm roof overhangs and shadecloth from roof edge to rails on ours
Windows mostly never see sun.

[Chotu]

Originally Posted by valhalla360

For $10-15 you can buy a huge roll of the stuff at any home improvement store.

Picking it up today. Prices are a bit more these days. Huge roll of the good stuff is $150, but worth every penny. I’m picking up a tiny roll for $13. Still a nice price compared to most things for a boat.

[Simi 60]

Originally Posted by valhalla360

For $10-15 you can buy a huge roll of the stuff at any home improvement store.

Never seen it in Australia

[Chotu]

Originally Posted by MicHughV

yes, I know the windows are done...I'm talking about placing the insulation in a frame...to reduce the overall size...a loose fitting frame...the size of the window, or the size of the window frame....but the size of the insulation, cut into....say....4 pieces..make the frame, so that the insulation has room to expand and contract..

Oh!!!!

I misunderstood. Sorry.

Same technique you were talking about with the windows expanding and contracting.

Ok, this one will be in the running too. First, I’ll see if the easy/fast way works. Just using silver reflective before the xps foam. Then onto yours. Then onto the shade cloths.

The shade cloths are my least favorite even though they are the most popular. Sorry everyone. I real dislike them for all those reasons I mentioned earlier and one more:

*insulating the windows from heat loss will also keep it warmer inside In temperate climates, on cloudy days, which I’m looking forward to seeing a lot more of.

[Chotu]

Originally Posted by Simi 60

Never seen it in Australia

Brand name of the good stuff in the states anyway is Reflectix. It’s available through Home Depot or in stock in the store at Lowe’s .

https://www.reflectixinc.com/

[rslifkin]

I wonder... For using Reflectix, could you make some simple, lightweight frames that hold the shape of a few sheets of it? If so, you could come up with a way to easily attach and remove the frames on the outside, with the frames preventing the insulation from rubbing against the windows and causing scratches. When not in use, you basically just have a stack of flat panels to store.

[BlueH2Obound]

Originally Posted by Chotu

Picking it up today. Prices are a bit more these days. Huge roll of the good stuff is $150, but worth every penny. I’m picking up a tiny roll for $13. Still a nice price compared to most things for a boat.

Here's one source, but grainger is top$$$. It's available elsewhere for about half the price or less.


https://www.grainger.com/product/39U...B&gclsrc=aw.ds

[Montanan]

Originally Posted by Chotu

I would, but there is a limitation.

My brand new windows are polycarbonate and a rubbing tarp will scratch them. That’s why I’m doing the protection from the inside.

Boom tents - shade with no contact or rubbing.

[StuM]

Originally Posted by Chotu

I’m imagining it reflects all that heat and light straight back out. Is that not going to happen?

No, incoming and outging radiation will be at different wavelengths depending on how much is absorbed and re-radiated by whatever is on the inside of the glass, the window material may well be opaque to the outgoing radiation wavelengths,unless the reflecting material is a good reflector at all relevant wavelengths (visible , IR and UV)



It's why the inside of a car gets so hot when it is sitting in the sun.


(See "greenhouse effect")

[Spot]

Do not feel too bad, NASA had to do the same thing with Skylab...

[valhalla360]

Originally Posted by Chotu

You just struck the fear of god in me!!

The polycarbonate melting point is, very conservatively, 220F. I do have black Frit bands painted directly on the inside surface of the polycarbonate around the edges of each pane. That doesn’t cause a melting situation.

Will the reflective surface be worse than black in direct contact with the plastic?

I’m imagining it reflects all that heat and light straight back out. Is that not going to happen?

This is pretty confusing. But I better just do a single test window to be sure the windows don’t melt too.

Jesu, I hate this climate.

My understanding...The stuff isn't perfectly flat. If it forms a concave curve, it can focus the light reflected back on a single point.

Might have been a different plastic but I've seen a couple cases where they think it was the cause of rippling. Hard to say for certain. It would have to be a really hot day with the sun at the right angle. Hard to duplicate, so it might have been something else.

Glass windows, I wouldn't think twice...in fact there is a piece right next to me now but it's in the RV and the windows are glass.

PS: when I said a huge roll, I meant larger than needed to cover the windows...not the giant rolls for doing a whole house.

[Chotu]

Well, that didn’t go as we thought.

It worked perfectly! Ha ha

The result is the foam does not melt or bend once I put the reflectix on the outer surface.

Not only that, there is a side benefit. The window I tested it on is not suffering from all of that warping and bending that the other windows suffer from now that this material is there. Oddly, it took away a lot of the thermal loading on the window pane itself.

Rather than reflecting heat straight back into the window and it bouncing around in the air pocket, it’s reflecting I guess everything right through the window. Without heating up itself. So everything is staying nice and cool. There is no hot pocket of air in between the window and this material like there was with the foam insulation only.

A perfect solution. And no tarps! LOL

Now I can just store these panels down below where I store the window screens. I have an area for these types of flat panels. Problem solved. I am almost ecstatic.

[Chotu]

Originally Posted by Montanan

Boom tents - shade with no contact or rubbing.

I’m not there yet. I don’t have a boom. LOL or a mast. Well, at least neither are on the boat at this time.

[Chotu]

Originally Posted by StuM

No, incoming and outging radiation will be at different wavelengths depending on how much is absorbed and re-radiated by whatever is on the inside of the glass, the window material may well be opaque to the outgoing radiation wavelengths,unless the reflecting material is a good reflector at all relevant wavelengths (visible , IR and UV)



It's why the inside of a car gets so hot when it is sitting in the sun.


(See "greenhouse effect")

Yes. This is precisely what happened. The infrared was trapped by the insulation and by the window. And the infrared was stuck with nowhere to go. The visible I believe, turn to infrared as it hit the insulation. And just built up in there. In the air pocket.

Now, with the reflective surface on top of the insulation, no problem at all. Everything is cool to the touch. Even the window. Which is not even cool to the touch without insulation in the frame.

Oddly, it has solved a lot of my problems. The thermal expansion is even gone now. To a great degree. I would say it took away 80% of the thermal expansion problems that I was having with that particular window pane. It’s interesting because I only did one window. And the other ones are all expanding as normal, but this one with the insulation did not.

[RKsailsolo]

So to summarize, the polystyrene foam and reflectix sandwich is mounted on the inside of the window with the reflectix directly against the poly carbonate. Right?

Fascinating solutions thread. Thanks for letting us learn alongside you.