Tin Foil inside windows?

[SillyCs]

Hello forumers!

On the hard for a few months. We put tin foil (the rolls we use for cooking) inside our salon windows and it’s remarkably cooler inside. However a thought came to mind. Am I risking damage to the windows and hatches? We are a 50’ sailing cat.

Ok share thoughts please.

Thank you in advance.

- Coy

[Avionics_Joe]

YES, you are doubling your radiation. Put the AL foil on the outside.

[Chotu]

I would not worry about doing this. I have reflective surfaces inside of mine as well. Especially given that you are not going to be doing this all the time and you are only on the hard for a few months.

[Tin Tin]

A lot of catamarans use foil bubble wrap, probably easier to manage than tinfoil as more robust and could possibly be used outside if desired.

[Quadrille in JB]

We did this in Greece with the boat on the hard for 2 years. It definitely kept the boat cooler but the aluminum foil adhered to the windows and was a real bitch to remove. We had to scrape it off a little at a time with our fingernails.

[NorthCoastJoe]

My Pearson 30 has had aluminum foil inside on the forward windows for 5 years now with no problems in the California sun. Biggest hassle is keeping it from falling off by using just friction, I am sure tape would help.
I also use aluminum foil duct tape on the inside of the camper shell windows of my truck in California to keep it cooler in summer It lasts for years.

[JPA Cate]

There are other ways to cut down the heat, such as shade cloth covers for the ports and hatches. There are many varieties of shade cloth, from agricultural to Breezeway, to cut down from about 20% to about 80%. They are fairly easy to make, and can be placed over the ports and hatches with press studs (snaps), or other marine fasteners. You can usually still see out, too, it just looks shady. In Oz, it is marine trimmers who stock what you'll need. In the US, I'd check SailRite.

One of my hatches is covered with Breezeway over the hatch, and sunbrella scraps were made into the sides, with elastic binding it; my forehatch has a stamoid hatch dodger based on the dorade principle: it comepletely covers the open hatch, which has baffles arranged so that rain doesn't come in.

Having the shade cloth over the outside of the acrylic "windows" will help them stay cooler, acrylic expands quite a bit in the heat, and will protect them from UV damage, which Al foil won't do.

Ann

[LakeSuperior]

Foil reflects 95% of the near infrared, visible, and UV portions of the solar spectra where most of the solar energy making it to earth surface is.

So applying it inside of the window reflects most of the energy back out the window. Consequently, it makes sense to apply on the inside. It would work only fractionally better applied to the exterior.

Sorry Avionics Joe, you failed on this one.

[hugosalt]

Sail here in New York during winter and use above mentioned bubble wrap foil cut to fit ports and hatches and some non living spaces. Makes big difference keeping heat from diesel heater in boat.
As I understand it not alot of R value but reflects hot/cold very well.

[RaymondR]

Originally Posted by LakeSuperior

Foil reflects 95% of the near infrared, visible, and UV portions of the solar spectra where most of the solar energy making it to earth surface is.

So applying it inside of the window reflects most of the energy back out the window. Consequently, it makes sense to apply on the inside. It would work only fractionally better applied to the exterior.

Sorry Avionics Joe, you failed on this one.

I could be wrong but I think the OP is worried that the UV in the sunlight will damage the acrylic or Lexan on the way in and then again on the way out after being reflected from the foil.