Chrome wrap your roof!

[oldtamiyaphile]

If you live in a hot climate, you probably find your summer economy is worse than your winter economy.

That A/C sure takes a lot of fuel to run.

My van has a lot of roof space, just soaking up the sun. Worse, the cargo section doesn't have a headliner so all that heat is transferred directly to the interior. While the cab has a headliner and is partitioned off, the steel partition isn't insulated so it transfers heat from the cargo area into the cabin in time.

I also have paints and sealants in there that have a longer shelf life the cooler they're kept.

'Before' pic:



Notice the strengthening ribs like a US Boxcar. They're up to 20mm deep, not good for aero.

So time for some chrome wrap.



The air pockets are intentional as this aids insulation, and helps aero. I did the whole thing in one piece, so I was never going to get it perfect anyway. If I was being really pedantic, I would have made little coroplast infills first so as to have something solidish for the wrap to sit on, but the whole thing is being covered in solar panels anyway.



On a cool 25*C day, I found a 22*C delta. That's only going to increase when the sun is really strong, or if you have a darker coloured vehicle. Even compared to white, chrome is still roughly twice as reflective.

With my van being around 7' tall, the wrap is invisible from normal viewing angles, and the paint is now protected from bird droppings (hard to keep something clean if you can't see/ reach it readily.

Unintended consequences

The roof stays so cool now, that a shower in the morning means the roof is still wet in the evening.

[cRiPpLe_rOoStEr]

Seems like a good solution. I have already seen it in buildings. BTW how does it attach to the roof? And is there any intermediate layer to enhance the insulation?

[oldtamiyaphile]

It's peel and stick, like a giant piece of sticky tape. It's cool enough now that additional insulation isn't really needed, but you could add lining on the inside of the roof like they do for camper van conversions.

[Xist]

Semi drivers must not like you, but otherwise it sounds like a great solution.

[oldtamiyaphile]

When you consider the angles, I suspect the sloping rear window of a sedan is far more annoying than my roof ever will be. So far, no truck driver has seemed to notice. My bigger concern is birds attacking it.

[JockoT]

Originally Posted by oldtamiyaphile

If you live in a hot climate, you probably find your summer economy is worse than your winter economy.

I wish! Here in Scotland I get my best mileage in the summer (we are into September, and already the FE is dropping because of the weather). Mind you, it is always easier to get warm when it is cold, than keep cool when it is hot. My car doesn't have air conditioning (last one did) and I have only missed it on about three journeys this summer.

[seifrob]

So large, so complicated surface! How did you manage to wrap it and not get tangled? I am planning something similar. Would you mind to share your method in more details? Did you wet the roof with washing up liquid water? How did you layed it? Is it e-bay wrap, or special brand?
I am almost dying out of curiosity. My father has the same car and I was considering to use silver spray on the roof. Your solution is better.

[cRiPpLe_rOoStEr]

Originally Posted by oldtamiyaphile

I suspect the sloping rear window of a sedan is far more annoying than my roof ever will be.

My experience with trucks had been quite limited, but the sloping rear window of a sedan does seem more annoying anyway.

My bigger concern is birds attacking it.

Why would it be more prone to bird attacks? Anyway, in case it does happen, would be interesting to check if this chrome wrap would protect the original painting from damage.

[Xist]

Don't birds hate reflective light? Isn't that why some scarecrows are made of tinsel?

[oldtamiyaphile]

Originally Posted by seifrob

So large, so complicated surface! How did you manage to wrap it and not get tangled? I am planning something similar. Would you mind to share your method in more details? Did you wet the roof with washing up liquid water? How did you layed it? Is it e-bay wrap, or special brand?
I am almost dying out of curiosity. My father has the same car and I was considering to use silver spray on the roof. Your solution is better.

I have a bit of experience tinting my own windows, so that helped a little.

Doing it in one piece was definitely a risk. It's eBay wrap, I couldn't find any branded wrap for sale in small quantities locally.

I just applied my wrap dry. I don't think slip solution would be much help in such a large area, it would tend to try out before you can really use it. You need two people and at least two ladders - ideally a pair of platforms.

Prep with Iron-X and clay bar to 100% decontaminate the paint.

I started by rolling out the wrap out on the roof. Wrap comes in 1510mm wide so I had to trim a bit off the width, I just used a pair of scissors and followed the guidelines on the backing paper.

Then I rolled it back up in reverse (so that the wax paper side faces out). I started at the front and peeled back about 30cm, stretched and stuck it down in place. This part needs to be perfect as if it's even 1mm out, you'll be quite askew by the time you get to the end. Then I just worked back pulling on the wax paper and keeping it taught.

Wrap is much easier than tinting, small bubbles come out via little channels in the film, though they seem to seal up if you try to get too much air out of them.

Wrapping was actually easy and fun (and cheap at about $50 to do a big roof), I plan on doing more of it. I've ordered a roll of shadow chrome to do the uninsulated matte black roof on my Jeep. You can really feel the heat radiation off that thing as matte black is the hottest possible colour

I like the black roof look so I might shadow chrome the visible front part of the van roof depending on how it looks and how it performs.