I need a reccomendation on a heat resistant material for temp up to 300 degrees. Will be used in solar water heater. Should be readily available and inexpesive.

Glass.

Steel, aluminum, casting iron, stone...

If you go for glass, I'd recommend pyrex.

 

What shape does it need to have? What are other requirements?

What part of your solar water heater do you need this material for? Heat conductive material is best for housing the pipes - that way any heat absorbed by it from the sun can conduct through the pipes into the water easily. You can insulate the body of the the unit, but heat conductivity is what is needed between the pipes and the heat capture sheet/housing.

 

The use of 'squashed' copper piping painted black improves the absorption too iirc. Black for obvious reasons (it absorbs the heat), squashed slightly so that a larger surface area of pipe gets incident rays and thus more absorption of energy.

Glass.

how come glass is heat-resistant ? My glass mug was broken in steaming pot.

Was it cold when it was put in the steamer? Was it a thin glass mug? The glass here that John suggests would be much thicker and wouldn't be going through fast temperature changes.... extreme temperature changes throughout the year, yes, but slow changes that wouldn't cause it to shatter.

how come glass is heat-resistant ? My glass mug was broken in steaming pot.

How hot was the glass when it was made?

no need extreme temperature.

I never challenge steamed eggs with any glassware/porcelain afterwards。

glassware is not heat-resistant, stainless steelware is.

Depends on the glass.

The mug probably wasn't borosilicate glass (aka pyrex), which is the kind of glass oven ware or lab equipement is made of.

"Regular" glass is definitely not heat resistent.

 

But even heat resistent glass isn't as heat resistent as metals.

Edited March 29, 20178 yr by Bender

The mug probably wasn't borosilicate glass (aka pyrex), which is the kind of glass oven ware or lab equipement is made of.

"Regular" glass is definitely not heat resistent.

 

But even heat resistent glass isn't as heat resistent as metals.

That rather depends on the metal: ever seen a "mercury in glass" thermometer?

...

glassware is not heat-resistant, ...

A lot of laboratory work shows that you are wrong.

That rather depends on the metal: ever seen a "mercury in glass" thermometer?

 

Why do you ask? Do you think mercury is a common construction material?