www.greenpowerscience.com This is a 64″ spot Fresnel Lens with a max temperature above 3000f. The concrete and rock shatters from the temperature shock. Slowly adding heat allows for melting. The rock was exposed for 60 seconds and the two pieces heated 8 ounces of water from 68f to about 130f within seconds.
Did you mean Bisphenol A?
ok i admit thats dangerous !! very dangerous; if i had this at home i wouldlove to creat things with molten glass; maybe some lenses;
or surely melt steel or aluminum and creat little swors for decor ::
many things can be done, but i have no way of gettig this big ass lens !!!
LAVA AT 00:32 !!! Oh Crap !
This kind of video always brings out the kid in me.
Gracias, amigo! Now to actually try it – and the Fresnel Lens!
watch?v=4MhCYJqkgh8
HAve you ever made your own fresnel lens?  I was thinking of buying a sheet of clear plexi and use a router or dremal to carve a spiral from the middle out. Clean excess plastic shards and dust. Take a hand torch and hit the plexi just enough to remove cloudy or matte finishes without melting or discoloring the plexi. Hopefully this creates a fresnel.
You wrote: “after 72 hours, fill with water”… how long to keep water in the bowl? When to empty and let concrete bowl dry out?
Thank you for such a quick and detailed response! Now I can give it a try… and interested in creating solar hot water here in Guatemala where I live at Lake Atitlan. Your videos are so informative and inspiring; now I can give it a try! Especially with the Fresnel Lens. Had no idea it could be so powerful.
Sink in water for 1 hour. Remove and allow to dry for 24 hrs. Then you can place in the sun to dry. The water anneals (sort of annealing usually refers to heat) the cement allowing slower cure time and a better cross linked structure preventing tiny cracks/fissures. Bubble holes can be filled with cement. Wet the bowl first prior to smoothing layer as this provides better adhesion. 24 hours is fine if your mixture was perfect. Most add too much water. Depends on humidity and weather.
Hi,
Pure portland cement vs adding sand creates a stone like structure vs cement deck. Builders mix because of cost and also decks should have rough surface for wet no slip etc. The lower the sand to cement mix the higher the strength rating. Bowls are small volume so one 80lb bag can make many. Cement is endothermic when hardening. once the molded material is firm (cure in the shade higher humidity) about 36hrs. spray with water. After 72 hours fill with water or sink in water.
I want to make the concrete bowl in the video. I have no experience with concrete, so have questions. You wrote (at 2:01 min):
“Fill one bowl with pure Portland Cement halfway and press a second bowl down until the cement squirts out. Let it set for 24 hours. Add water after setting and firm to harden the cement.”
Are you saying to fill a bowl with wet Portland Cement & then add more water after 24 hours setting? How much water afterwards? Fill the entire bowl with water to “firm the cement?”
@ FarceTheory the can liner in your statement is called, Biphenol A , the most widley produced chemical that is introduced into north american diet that exists. Research it. Learn and be wise.
Dan your videos as always – are mind food.
I was referring to the aluminum can, Witch is not toxic in a solid form. Any beverage in a aluminum can will dissolve it and become toxic just like lead. To fix this problem the can is given a plastic liner. There for he was burning plastic!
Neat video.
Interesting, I doubt gazing into that bright spot is nutritious for your naked eyes. I would even be concerned about my camera sensor. Could you do a back of the envelope calculation how many watts sun delivers on the spot. Maybe if we new the color temperature of molten aluminum and the boltzmann dist of it we could guesstimate. But there are simply too many variables to factor, ambient air the concrete soaking some energy due to chemical reactions etc. I am looking forward for an answer Thanks
CONCRETE
he probably means the plastic lining in the soda can.
No offense Moses, but who needs the Arc of the Covenant when you have Danny Boy’s Fresnel Lens?
Plastic?
I never thought you would burn plastic. But at least you had some gasification going on.
Very cool slow Mo 🙂 Comet styles!!
I realy like your video’s. Will the Fresnel Lens cut though rock?
Didn’t you make the Cement brittle by dropping it in the water?
I agree. This setup begs application. Casting the aluminum cans you find on the streets into something pretty and useful would be awesome.
And a lava rock casted in the shape of a statue, wouldn’t that be kinda novel? You might do a small one in one go, and a larger one by just topping the mold off bit by bit.
Dan, I applaud your work and video editing quality. Awesome filters. Glad to subscribe.