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Solar deathray smelting? Answered

So Im not sure of the capabilities of the fresnal lens in terms of maximum temperature but I've seen them melt brass. I was thinking with a solar death ray on top and a charcoal fire on bottom that I could get temperatures to melt steel. I have drawn a rough sketch of the overall Idea I really need someone to further refine this idea into a working schematic that I can create when I do I'll document it all and relay the results on here to help others recreate it.

Now This setup will be behind my greenhouse on the corner of my property on the side that would be hidden from the sun, however if the base pivots on an axel I'm thinking of using, then it will be able to catch the sun from all the points when it's most useful. In that I'll also have the fresnal lens on a pivot bar to help get it on my focusing lens which will be a plastic and water style parabolic lens my only concern is that if I can't turn that lens will it hinder my project entirely or will it be fine, plus I'm not sure about focal point on this kind of lens. On the sides of the frame I'll build for the fresnal lens I'll have strings attached for turning on the bar and I'll be able to lock it in place to keep from fires around my smelter.. Hopefully!

Overall dimensions may appear small in the drawing but the fresnal lens should be at about I'm guessing at roughly 25 feet off the ground, or roughly 7.5 meters and the focal point in the middle will be found and adjusted to the fresnal in terms of height. I think it was roughly 1 meter so I'm not sure entirely I would love some feed back on this idea as I plan to make a smelter with it to complete my in progress foundry I'm building in my shed.


It's not going to generate enough heat to melt steel.

Brass melts at about 1800 degrees F. Steel needs 2600 degrees F to melt. If you get things that hot your greenhouse will catch fire from its proximity to it. If you burn coal you can get the fire up to about 2K degrees F but your still short of melting steel though you could weld iron. The lens idea isn't going to be able to make up the difference. For one the heat and gasses from the forge would distort/melt the lens and refract the light heavily rendering it useless. The lens alone won't be able to generate the desired heat. If you want to melt steel you'll want to build an induction furnace.

If you really want to make a foundry then start smaller. Make a nice charcoal furnace with a hair dryer and some bricks to start melting Aluminum.

Also I was going to do the brake drum forge, I've got all kinds of scrap around my place and such. Just tying to come up with a good schematic and deciding on what I want to build it with as far as stone type. I have countless creek rocks at the creek, but I have sand stone everywhere I want to put it to use somehow.

I just forged a shortsword from iron and rounded a handle out on it and everything, I did all that in a campfire, I threw some cans in on top of my sword and they melted down on top of it lol So if I can get a bonfire that hot WHILE its raining, we can put our bar a bit higher than aluminum lol.
However I do see the point your making thats why I put the second picture with a 2 in lens from a rear projection tv because I was thinking about the gases coming up on the plastic. I submitted the first idea right when I woke up, twas what I was dreaming about, and changed it midday.
But I have looked at induction forging I'll have to check out the smelting since you've brought it to my attention.

Interestingly enough i was watching some blacksmithing videos on youtube on Sunday and saw this one on a $40 brake drum forge. This guy was pretty informative. I'd embed the video but Java here at work doesn't work right.