Stainless BBQ as Solar Oven?

[Divevac]

Lots of discussion about solar ovens in the archives. Has anyone ever tried painting a stainless bbq with matt black high heat paint in an attempt to convert it to dual use: propane bbq and solar oven? Would any apparent wind erradicate the black paint's efforts to generate sufficient heat to cook?

ANy thoughts or suggestions are welcome...

[Steve Bean]

I think this could work. Certainly not hard to try. I would suggest amplifying the heat gain with some reflectors. Wind would tend to cool it but I don't think it would hurt much.

[john61ct]

Warming temps maybe rice, doubt if hot enough to bake bread

[atoll]

Originally Posted by Divevac

Lots of discussion about solar ovens in the archives. Has anyone ever tried painting a stainless bbq with matt black high heat paint in an attempt to convert it to dual use: propane bbq and solar oven? Would any apparent wind erradicate the black paint's efforts to generate sufficient heat to cook?

ANy thoughts or suggestions are welcome...

stainless steel is a very bad conductor of heat,so even if you could get the surface temp high enough to cook it would not transmit through the surface to create temperatures sufficient to act as an oven inside.

better would be to use some highly polished stainless plates to direct the suns rays onto a sealed tube of mild steel or cast iron painted black outside for cooking inside using the same principles as a pressure cooker once enough heat is generated.

[sparrowhawk1]

Well mine's not painted but the stainless steel gets quite hot. But not hot enough for an oven. But awesome temps for dehydrating herbs

[sparrowhawk1]

I just had an idea. Get a vacuum tube and make the reflectors so that they can Stow inside the grill when closed, and when the lid is open you open up the reflectors and my grill is on a post so I could rotate it to follow the Sun. And then when you want to use propane just take the Sun Oven out and once the grill is cooled down put it back in, perfect storage space, Perfect height. Out-of-the-way secure place.
Edit. I just did some research and the standard vacuum tubes are too long to store it. But it's still a good stand if you make it so that it can be locked in securely.

[alicebarrie]

I think it hard to make it.

[GrowleyMonster]

Won't cook. Will warm, though. To cook, you need some nice big reflectors to concentrate a lot of solar radiation onto the grill. BIG reflectors. And you have to shift them as the sun moves. So, not really practical though it might be entertaining to try it on land in a nice big backyard. You would want to keep the reflected heat in, by enclosing the whole thing in glass. It would take quite a cumbersome setup to cook at any reasonable temperatures. OTOH, a large cardboard box lined with mirrors or even aluminum foil, including the top of the box left hinged to it, with a cover on the box itself, has been used to heat a black iron pot to crockpot temperatures.



You have to not only have a surface that will absorb solar heat, but also concentrate a lot of solar rays, and also prevent the escape of heat. And even so, results can be underwhelming unless you really go big.


I do think that the drying herbs idea is a good one, though.

[sparrowhawk1]

It's working very well to dry out my mint which for some reason makes better tea when it's dried first. There are lots of videos on YouTube of making your own solar oven with a cardboard box but Styrofoam coolers are super cheap and with a small piece of plexiglass and some aluminum foil you can get temperatures of 250 degrees and higher

[AiniA]

I did some work with solar cooking in Africa and a couple of things come to mind. The first is that the wind will kill any real heat you generate with the black-painted interior. You will need a clear cover to let the sun in and keep the heat from escaping. The other is that you need to be able to turn your 'over' toward the sun. The units we distributed in Africa, mainly to grandmothers who were looking after their grandkids after the parents died of AIDS, were not very large but worked quite well, but it was a very sunny place and the users would adjust the orientation quite often. I think the ovens were made by a small company in South Africa.