The store bought blankets usually have a foil on them but have (usually) fiberglass insulation on them. The foil by itself wouldn't have much insulation value so I would think it'd be a waste of time and money. Glad you're trying to think out of the box though and come up with some unusual & frugal ideas!

Some people around here are using shiny surfaces and claim that it bounces heat (or cold) off.

I must confess to being rather sceptical.

I guess I'm sort of from the "old school" ... in that I last saw the inside of a classroom (after having spent some years in the workforce) 50 years ago this spring.

ole joyful

I had thought about that and there is value to reflecting. For instance in the kerosene heaters, many have a reflector in back to reflect the heat out, as do many electric heaters. I'm thinking though that when against the heat source it would conduct the heat rather than insulate.

I do recall that the idea of the shiny surface of the foil reflects the heat better than the matte side is a myth according to Reynolds Aluminum. There is a difference on which side you use if you use the "Release" foil!
It hit me that we wrap food in foil to cook. First it conducts the heat, but I guess it does tend to keep some heat in, although moisture is more likely isn't it? Guess it's really not stopping the heat transfer so much as being the moisture barrier. I do use foil on occasion if I don't have a lid for a pot, but then again, that's the moisture and spattering issue.

The other point is that a heavy duty foil is not exactly cheap and the cost wouldn't be far from the cost of a water heater blanket, would it, by the time you get enough on there to cover it. How many rolls would it take? I'm not sure.

One warning, be careful on insulating gas water heaters. Be sure you don't affect the airflow and the ventilation on the heater and of course place nothing combustible near the flames.

But you do have me thinking now.... what would make a good, frugal insulating blanket? Bubble wrap with the foil? I'd think a moving pad would work well but I wonder about flammability. Rip some insulation out of Joyful's ceiling when he's gone???? ;)

A water heater blanket is cheap - 15-20 dollars. Even just 3 rolls of heavy duty foil would cost more than that.

It seems unnecessarily complicated, labor intensive and probably ineffective.

Are you thinking of having the foil tight against the surface of the heater, or of leaving some space between - maybe a half inch? I think that they say that if there's an inch or more of space in a window, that convection will take place between the cold and hot surfaces.

If so, what would one use as spacers between the tank and the foil wrapper, to keep the small interval constant?

Also, the foil wouldn't be the only cost ...

... another use for duct tape!

If you use masking tape or clear tape, it'll deteriorate after three or four years and need to be replaced.

How be you use some of the foil to make a medal for yourself, labelling it, "Shining example of energy conservation"?

You could even make a large one, with a mirror in the middle, with a small hatch covering it, which you could open using air through a tube from a bulb in your pocket, that you could squeeze when you meet someone who's a good example of an energy conserver, especially an innovative one.

You could even carry a camera to take a picture of the smile on their face when they saw their face in the mirror.

Of course ... then they'd want such a medal, as well, no?

The sale of such should finance the foil (plus duct tape) for your water heater.

Or your share of a generator's purchase to service half a dozen houses' freezers, fridges, etc. in case of power outage. Maybe even a furnace ... if local code will allow you to install a push 'n twist plug in the line to your furnace.

Dang! You pinch my insulation ... it's up to the landlord to replace it ...

... but the guy that hurts is I ... cause I have to pay for the oil!

Landlord's worried about a couple of evergreens whose branches are nearing the power line (one touching). So ... he girdled the tree, about 8' from the top, figures the branches'll die, maybe even the wind knock the top off, eventually.

He's a sod farmer, chairman of local conservation authourity.

It seems to me that we need to get serious about energy conservation ... not only due to the need to conserve it, but for warming and polluting reasons, as well.

If we think that we've had trouble thus far with regard to all three of those problems ... just wait till Asia and South America get into high gear!

Enjoy spring.

ole joyful