How To Make Solar Concentrating Mirrors (super HOT focal point)

[@Nighthawkinlight]

Yes, I did repost this video. Last Thursday it seems KZbin was having some internal problems or perhaps was running an experiment with the promotion algorithm where videos posted on that day were shown to an unusually small amount of people. Reposting a video almost always results in worse performance than the original, but in this case so few of my subscribers were able to see the clip when I published it that I decided it was worth the risk to give a few more of you the chance to watch. I also wanted to add an additional warning about the vapor of the dichloromethane paint stripper I use in the video as it is a rather dangerous chemical if not used carefully. It must be used with a lot of ventilation as it is metabolized by the body into carbon monoxide and poses similar risks.

[@kenshiromilesvt.7037]

NightHawkInLight I was actually going to watch the vid again to get the brand name of the aircraft paint stripper and got the notif today lol. Thx. love all your vids and GreenPower as well. Very high quality videos that have cleared up a lot of uncertainties for me. Keep it up!!

[@rianmach9043]

Thanks for re uploading it! I always insta-click your videos when I see them pop up but for some reason it wasn’t there. Hmm

[@hiimmike_r]

Didn't make the video worse.

[@purplejerry1]

glad you reposted since I seem to be one of the people who didnt get notified :)

[@FlesHBoX]

youtube's terrible promotion system is why I just view all new videos from my subscriptions instead of relying on a broken system to delivery interesting content... Of course, this means that I rarely discover new channels, but it is the only viable solution until youtube gets their stuff straight (if ever)

[@theCodyReeder]

I’ve used carburetor cleaner to remove the paint, the benefit of that is the high pressure jet helps remove the paint no scrubbing needed.

[@BeeKisses]

YES Cody!! Can't wait to see your video on it!!

[@danielpas368]

These puny mirrors aside, make a giant one out of a space blanket and melt rocks with it!

[@Chromwel-A]

Daniel Pas kinda remind me a bit of death star.

[@markowease9947]

I don't mind watching it again. And i shall watch it again . I love how in depth yet simplistic you make everything seem to be. Please keep up the outstanding work. Love your Channel.

[@electronicsNmore]

The video brings back memories of years ago when I built my 12.5" Newtonian telescope. The 1" glass was ground down and aluminized. Great video!

[@Nighthawkinlight]

Did you hand grind your mirror? I've been watching some videos on the process. Astonishingly I've read that hand ground mirrors can be made to tighter tolerances than is possible by machine, though that fact may be out of date.

[@kaczkinson]

Hi :) I'm thinking about making my own telescope, but I got no idea how to do it in the cheapest way. mirrors for telescopes are not cheap :(

[@scottmichael3745]

@@kaczkinson I bought a 6 inch telescope mirror off of eBay for $30 years ago.

[@jeremytheimer7443]

@@scottmichael3745 no way, nowadays a 3 inch telescope is 100 dollars,

[@David-bc4rh]

@kaczkinson I've had this Telescope Building with John Dobson about hand made telescopes showing up in my recommendations and it is very interesting. I believe the handmade method would be project overkill if the desired use is just to focus the sun, however, the option it use it in a powerful telescope in the future would be available. All the really hard work has already been performed, lol

[@JavierSalcedoC]

Glass made pot covers make for an excellent glass concave surface to make this project. Cheap, no paint to remove, small hole in the middle for support, many sizes available. You'll need to apply the reflective paint of course

[@nikolasangelides1481]

No problem for reposting! Im happy to watch it again! Keep up the good work

[@trcostan]

You should read about the solar collectors used to simulate the thermal pulse of a nuclear bomb. Crazy how powerful the roughly 1kw/m2 of the sun is when you focus it to a small area!

[@willcool713]

I know this is a very old vid, but this is a thought experiment I run in my head, ad infinitum: How to make a big mirror for a Dobsonian telescope. There was an article in Popular Science, I believe, which had a great method -- basically a 15"-20" bowl, on an old record turntable with the central spindle removed, filled with very slow setting epoxy. And set the whole thing up on some foam in a place far from traffic or other vibrations. It creates a parabolic surface, the focal distance determined by the RPMs of the turntable. But you still have to send out for silvering. I love to think on ways to achieve such a surface myself. This is a clever solution (and I wonder if polishing might improve optical quality).

[@diesockedeslebens6599]

Hey what do you think of diy plasma sputtering for the reflection property's. I love the turntable idea, any new info?

[@willcool713]

@@diesockedeslebens6599 No. Most ideas have fatal flaws. Putting a coat of thin chromium paint on it while still spinning, is the best I've come up with. Thin, runny paint which is still dense enough to cover the surface doesn't seem too difficult to come up with, and that would leave the layer on the surface very thin, to minimize imperfections due to drying. I dunno if you'd get even atomizing with plasma. Ideally, you'd want a single molecular thickness on the surface of a perfect parabola. I have heard of other people using the spinning motor, but with a bowl of mercury as the reflector. If you can isolate interfering vibrations, then that kinetic mirror would be beautiful. But it'd need mountaintop sorts of isolation.

[@charliesteiner2334]

@@diesockedeslebens6599 It would be a heck of a vacuum chamber, but you could do it. For real big sizes you probably want an atmospheric pressure process like chemical vapor/solution deposition. (A lot like how they silver normal mirrors)

[@platinumsky845]

​@@willcool713 two minor corrections, first of all, metal doesn't form molecules in this kind of example and therefore is an irrelevant way of measuring, would be easier to measure in micrometers or nanometers at these scales. And lastly, ions don't "atomize" in the conventional sense. It's literally like a "field" of spray rather than a jet or stream, it's just about the most smooth and even coating you could get.

[@willcool713]

@@platinumsky845 Yeah, I guess I'm not familiar with the plasma techniques. I was imagining something makeshift, not precision. I'm still thinking along the lines of a chromium flake paint with an evaporative base that effectively leaves no binder. But even a thin clear top residue might be okay at the resolution I'm likely to work with. Putting it on while spinning ensures any slight excess conforms to the same parabola. It wouldn't be a perfect surface, but if the mirror were large enough it could probably stand up to 8K imaging, as long as the rest of the optics were quality. Not sure how far you could push the resolution for optical zooms, but it would be easy to image, say, craters on the Moon and see how precisely you can focus. If the surface distortion is less than atmospheric twinkle, then it's good enough for my purposes. I've just about got a plan. I'd really like to create a cheap, big mirror that's easily replicated.

[@GREENPOWERSCIENCE]

Awesome video Ben!

[@ninjanoobnil]

Are you verified

[@superdave1263]

@@ninjanoobnil Last I checked I am verified.

[@joehopfield]

Using smoke to show the difference between curved & parabolic - deeply satisfying.

[@MiguelAbd]

I did get the video last time you uploaded, but I'm fine with watching it again haha

[@BeatlesCuber]

Miguel Almeida me too.

[@joeyho5134]

I'm glad you reposted this video as the concept may become a valuable part of my project. Thank you very much.

[@king4aday4aday]

If you wanna go bigger, one method I remember mythbusters trying is stretching a mylar foil (space blanket) over a large cylinder (turkey fryer or something), and pulling a vacuum. For that you can either drill a hole on the bottom and add some fittings and pump out some air, or you can also heat it up a little, and then stretch the foil quickly, and as it cools it will stretch the foil in a paraboloid.

[@theantichrist6524]

That was a good video I was able to finally see exactly where the focus point was when you used the smoke test

[@TelecasterRon]

I have built some telescopes since 60's. However also Solar Furnaces as well in the 80's and 90's. They sell a 4'x8'x1/8" sheets of acrylic mirrors. Base upon 100 watts per foot. You can easily reach temps over 1200 degrees..It will be a second surface. Which will eliminate surface deterioration your first surface ones will encounter guickly. There are telescope film coatings that will slow oxidation and degradation. I typically made a 8 foot single plane design. Y²=4sx or by taking two tape measures you can easily draw an accurate parbolic curve on plywood for the ribs. I used 5 or six after cutting 1 to use as a pattern for the others. Careful cutting and sanding and clamp them together aligned precisely and get them all sanded then bore holes through the them to provide for 3x8 all thread rods. With nut and washers you can make a 4' wide 8 feet long mounting ribs for the backing and use a 4' 1x4 on the end or a outside metal corner to force the flexible mirror to conform to the ribs. 3.2 kws is easy. Note a curve ratio of dia. or length to focal point of around .5 is good. Or in this case about 48" F.P. I built a equatorial mounting for the ones I made. Test revile about a 60-70% efficiency. I used a glass encased copper tubing and backing plate black. Note it will shatter the glass enclosure around the collector if any moisture come in contact. A 3/8" wide 48" long focal point is hot and extremely brilliant. WARNING EYE DAMAGE IS INSTANTANEOUS. ALSO ONE DESIGN SET MY WIFES APPLE TREES ON FIRE. NOT GOOD. 25 FEET AWAY. BEWARE OF AXIS AND LONG FOCAL LENGTHS.. OFF AXIS SUN ANGLES ARE EXTREMELY DANGEROUS AND WILL START FIRES WITH IN SECONDS. I ALSO BUILT MOTOR DRIVERS AND TRACKERS USING SOLAR CELLS AND 741 CHIPS AND RELAYS. WILL TRACK AND RESET TO MORNING. OR WHERE EVER THE SUN IS ANALOG IS BETTER THAN DIGITAL. DECLINATION AXIS AND RIGHT ACCENTION AXIS ARE BOTH DOABLE. ALSO WATER CIRCULATION PUMPS YOU CAN USE SILICON DIODES AS HEAT SENSORS AND PUMP OPERATOR DETECTORS. DO NOT. DO NOT USE OIL AS A TRANSFER MEDIUM JUST TO FLAMMABLE AT THESE TEMPS. I EASILY PRODUCED HEAT GAIN OF 66-70 PERCENT. WILL MELT SILVER SOLDIER QUICKLY SO MAKE SURE YOU CIRCULATE WATER BEFORE SOLAR ALLIGNMENT. ONE FULL SATELLITE DISH DESIGNS ARE DOABLE. A 5 METER DISH USING REFLECTOR BALL MIRRORS WILL MELT ALMOST ANYTHING AT A FP OF APPROX. 3 IN DIAMETER. I HAVE A HERO 5 METER DISH WITH A 5 FT. FP. UNBELIEVABLE. HEAT. INCREDIBLY DANGEROUS ALSO. MUST USE WELDERS GOGGLES. Around 22.5 kw.

[@TheAstronomer]

What a beautiful show of spherical abberation. Well done. Liked and subscribed.

[@pocket83]

Interesting as usual. Thanks.

[@pezesu]

I'm so glad you made this video, my father found a mirror like this on the road and I had tried to make a parabolic mirror. Thanks to you I should be able to make one.

[@grayeagleswolves]

This was Really Helpful being an Rv person I can do this and have NO Bills thank you Love the channel

[@stevepapaw6615]

Excellent presentation, @nighthawkinsight. I've always wanted to make a giant telescope, but my problem was always the cost of the primary mirror. Thanks for sharing.

[@chrisellenback6210]

Yes, that's great!!! The applications are limitless

[@abettermousetrap]

a well spoken young man. Very interesting and well thought out and put together. Kudos

[@chriswentzel5339]

7:42 you can see smoke or vapor in the back ground hit the focal point and heat up and rise again...pretty cool Awesome video thanks :)

[@rangerbravo]

I'll watch it again. Fellow Michigander here.

[@Stevme0001]

I look forward to all your posts. I will be making this. Can't wait!

[@ElmaTVSouthAfrica]

Brilliant! I’m a 60 year old from South Africa, and very interested in solar.

[@ahoahat7919]

Amazing video: it's unbelievable of things you can do, with every day mirrors that you buy at a truckstop LOL awesome video dude! Keep them coming

[@kengamble8595]

Sure, I'll watch it again ! 😊 Thanks for sharing and take care. 👍

[@esau93631]

Always love to watch your videos! This video got me thinking more about altering the direction of a IR laser beam for a laser microphone used at large distances...

[@barthanes1]

Cool video, and thanks for the tip. I think one of those might be useful in a camping kit.

[@johnwahlers3363]

Video on a solar concentrator for hot water. I'm thinking copper tubing but I'll let you work out the details of the project. Thanks can't wait to see it.

[@MarkHivosk]

Thanks for showing the spherical mirror and how it focuses to a line rather than a point! Helps me with my project with focusing light I cannot see, 2.4ghz

[@avenuex3731]

Sweet! You might be amazed at how easy it is to PVD an Al coating on glass. You know, just in case you ever wanted a different focal point than a truck mirror.

[@abcstardust]

Thanks for another informative video. These mirror techniques are right up my alley!

[@roehle9962]

Know what? I'll watch it again. I won't lie, your videos are so informative and kinda have this hypnotic vibe... 😂

[@johnmeegan-w8o]

With this small size this might be good for cooking tea in metal cups

[@12thsonofisrael]

Good source for materials I had not thought about.

[@gearhead1302]

I wonder if you could use fiber optic cable at the focal point to transfer it to wherever you want

[@jamaicanbutter]

Wow, this video was very interesting and left me wanting to learn more.

[@BaronSpatula]

Watching again because I wanna help out an amazing content creator!

[@ThistlesGarden]

Love the shout outs to other channels, it's my favorite way to find new content.

[@quelinda8413]

Great how to video. Thanks so much for sources and descriptive information. Really appreciate your time providing this information. Thank you. I will watch again too. Just because it's so interesting.

[@henrykleyn3423]

Thanks for the great video. I learned quite a bit.

[@johnernest2779]

The more I watch your channel the more I'm impressed with your experiments. It's always interesting and your voice is clear and easy to understand. You must be a teacher in real life, if not, you should be! Thank you for interesting videos. I will be trying this as I did the star lite. That one really blows Mike mind as it works so well and can be used for many things. Sometimes I have plumbing projects that I need to sweat a pipe too close to a wall and worry about starting the house on fire. Now I can mix up a small batch and use it as a backstop behind the pipe I heat up. You should do a video of this mirror using the focal point to see if you can burn through the star lite as you already have both available and that would be a cool test of durability. Thanks again for cool experiments!

[@rajatroy1138]

Wow man the spherical mirror focus point was amazing ...

[@Wilder941]

I would love to see a project making a solar generater out of this.

[@spod32827]

Yeah with a mini steam turbine setup. If someone could develop a home-scale version of this... we're off the grid man! (except for internet connection obvs.) (and TV)

[@nicholasherrera1785]

@@spod32827 ha, well check this guy out for the wifi

[@nicholasherrera1785]

I am also interested in setting this up with a steam turbine. If you come across any resources on building one from scratch lmk please.

[@thomasroth4695]

@@nicholasherrera1785 check out a “ sterling engine”. Will get you on your way i hope. Good luck

[@TelecasterRon]

Read my post.

[@babybalrog]

OMG I thought i was down a rabbit whole and you bring me back to reality.

[@WhatAWondWorld]

It is interesting. Excellent method! Thanks

[@itsaaa_meeeeee]

Even better the second time 🖤🖤

[@anilshirsat4406]

Fantastic demonstration with also clear concept 💡 👌

[@MrHanumanthaReddy]

I love your way of expression it's very nice thanks

[@mico6181]

Very good teacher ! I do enjoy your shows everytime. Tqs.

[@Fabio-hc9bv]

I took a parabol mirror(tv) and put reflective foil on it. Worked great. I had to use welding goggles when i burnt wood for testing because it was extremly bright (looking at the spot).

[@ABaumstumpf]

First surface mirrors are used mostly for one specific reason: Ghosting. On a normal mirror a part of the light gets reflected by the glass it self. For scientific purposes you very very likely do not want that. The second reason why it is done sometimes is when the optical transparency of the carrier material is not as desired - normal glass mirrors absorb the near IR spectrum. It is not that much of the total power of sunlight. And if you do not need the mirror for "optical" purposes ( i mean like taking photos ) then you can get a big parabolic dish and cover it with aluminium tape, mylar or even tinfoil if done carefully.

[@EnjoyerofYoutube]

Your videos are so good, they almost mesmerize the viewer. Before I know it, they've ended, and I've been entertained the whole time.

[@TrollFaceTheMan]

As I said in the original video the info about the Aeroplane stripper is very useful, thank you.

[@alihaydartunc7249]

Very clever a technique. Congratulations.

[@anilshirsat4406]

Well explained 👌👍

[@ribeiroflyby9766]

I new member of channel. Im your fan. From Brazil.

[@clemkadiddlehopper7705]

the lenticular lenses from old big screen tvs are awesome, too

[@BarnabyFalls]

Excellent work!

[@LightningEagle14]

That is so cool! I love being able to see the focus point.

[@BhriguRoy]

Wonder if this can be used to distill sea water. use steam to create electricity and provide drinking water and salt as byproduct. free energy factories on coastal states with shortage of freshwater can use this to avert huge crisis if done rightly. This should work right ?!

[@seanregehr4921]

The only issue is the sun is not always clearly visible. Hard to predict overcast days, etc. But otherwise yes all that would work.

[@thomasgalpin5506]

yes

[@abbashussain2445]

it can be ised for areas which are sunny etc

[@ABaumstumpf]

If you want to create steam you need to focus quit a lot of light there and not let it reflect. There are simpler ways than evaporation to get clean water - specially as this is really wasteful in terms of energy to the point that it would very likely be detrimental to the area if done in a large enough scale to alleviate a shortage of fresh water.

[@benjaminantone9962]

What? For free? Helping people for free? How are people supposed to make money in that? Do you want the Rothchilds to not be able to afford their lifestyle? Next you’re going to want to cure cancer for free or something.

[@redditchrc960]

Sounds like Archimedes of Syracuse was right and mythbusters really debunked their own selves for doubting him. Archimedes was the first person to use this method and burn invading Roman ships over 2500 years ago

[@SakellarisNikolaos]

You can try an offset satellite dish by making reflective the surface😊😊

[@gerrymanuel7640]

thank you, will look for truck rear view mirror

[@CaptZenPetabyte]

Thank you. Ive been looking for something like this for a while to heat a small Sterling Engine for a proof of concept. This will help a lot! 😎🤜💥🤛

[@TheExplosiveGuy]

Instead of rubbing the paint residue off after the aircraft stripper (best stuff in the world, it even takes off powdercoat) does it's thing, use running water to remove the remnants to avoid scratching. Aircraft stripper can be cleaned up with water or soap & water without worrying about environmental issues (in small quantities, I'm not so sure about running quarts of the stuff down the drain). I've been using this stuff for years, though I prefer professional grade brands vs the hardware store stuff (penetrates way faster, dries slower). One other great use for it is etching patterns in powdercoat, you can make stencils out of Kapton tape (powdercoat masking tape) which the stripper won't touch, and if the edges are cut and bonded cleanly to your substrate, you'll get perfectly straight and even lines between transitions. Makes for a very sharp looking cutout in the powdercoat.

[@ARCSTREAMS]

7:50 was it actually reflecting studio light there? and did you have fog for visibility?

[@GrizaLeono]

Tre interesa ideo! Gratulon kaj dankon pro la montrado!

[@easymac79]

1:05 GreenPowerScience was one of the first channels I subscribed to like 10 years ago!

[@GrizaLeono]

Tre interesa filmeto. Gratulon kaj dankon!

[@madamlalsharma9646]

Very very nice and useful information

[@TheNames-4D]

Amazing. Like making a natural laser. There is so much more to learn here I think. For instance. What sort of energy could be created by lining up 3 or 4 of these, in such a manner that their points, all meet together at one point.. also could this be set up next to a “dirty water” supply, in order to make drinking water? Wow, the possibilities are countless. Thx

[@quelinda8413]

I love people that think, question, explore. Thanks for your curiosity.

[@mangeload]

Desalination via vaporization & distillation?

[@TheNames-4D]

@@mangeload absolutely. Free, sun made. Maybe a green house, made of magnified glass. All lasers pointed to meat all over the surface of the body of water. Now place many tubes, to catch the vapour, and drip into a clean water supply. Filter that through sands and solis, to add the correct minerals. And you have clean drinking water. Would work in hot countries as well as cold.

[@_Shubham_769]

Amazing video. Very informative for me.

[@NickFrom1228]

Can't stress enough about the gloves. I was applying varnish stripper on a summer day and was having to work fast since its quite volatile and evaporates quickly. I poured some out onto the piece I was working on then set the lid on the can lightly. When I went to grab the lid to lift it off for the next section, it caught and lifted the whole can up but then it dropped and splashed the stripper all over, including onto my gloved hand. Knowing this stuff is nasty I ran for the bathroom sink and was removing the gloves as fast as I could in the process. It still went through the glove and gave me a burn. I had a red hand for several days. Ironically its the same chemical they use to decaffeinate coffee.

[@atom2319]

Thank you for teaching this about mirrors

[@dayanidhirath3060]

Thanks for your efforts

[@SciHeartJourney]

Use a piece of charcoal instead of steel for the target in water. When I tried that, it worked great!

[@Nighthawkinlight]

That's a great idea

[@dondaue7456]

The stripper you used is named aircraft stripper but not to be used on aircraft .read container.It fooled me too bought it to strip greyhound bus.

[@legendsknigh6453]

Can user for telescope REFLECTOR

[@lahsiv]

Lol i bought a mirror and took it out and it didn't even have the paint backing...😂😂

[@vonries]

I was so hoping you had found a way to add the reflective portion to a surface. I would love to add it to the surface of a old TV satellite dish.

[@daveallen63]

Mirror window tinting film.

[@p38sheep]

I work with this aircraft stripper on a regular basis, easiest clean up method is water! And lots of it. It will also wash away the paint so all that is left is the bare metal!

[@AydaWalsh]

Awesome video!- Thanks for sharing!

[@mikebenoit6648]

I'm going to try the Sattlite dish and aluminum tape for a cooking outdoors

[@PTbyNIGHTEvents]

How does this compare to a fresnel lens? Regards

[@A.Netizen.Since.2010]

.. Fresnels are highly capable of melting rocks, sands, glasses & even thin metals... .

[@chrisking2824]

"gloves contact the stripper" haha XD 5:14

[@VisualBasic6]

neat ! i'll be keeping one in my car for sure !

[@Moohie]

Love you man , great content

[@fazliwajid611]

You are genius man. Keep it up. I love ur video especially solar tracking. please do some work on solar airconditioning, batteries, mobile energy storage system.

[@pauljames4991]

I once knew a model railway collector who used to dip his rail cars in brake fluid to strip the paint it did not damage the plastic but did take about 24 hours or so.

[@mesbahmodfree1288]

Hi over there....a cool vedeo I'like to know what's the the reflective shiny substance behind the spherical glass .thanx

[@yurikhakhnazarian7664]

very interesting. Thank you very much for nice video

[@colinprior7588]

you talked a bit about the fragility of the metal layer...do you need to apply something over it to protect it?...if so..what do you suggest?

[@BartJBols]

you could make the boiling in the testtube more efficient if you dye the water black. The light will penetrate the glass but get absorbed by the liquid directly.

[@Ruckusmatter]

this would be awesome for creating a large reflex reflector for a compact flashlight. with some 3d printed hardware and a parabolic mirror you could place the LEDs surface at the focal point and in theory get a super tight beam out the other end

[@michaeltichael]

I would like to see this concentrating mirror on a heliostat and using it as a heat source for your water distiller

[@yannisconstantinides7767]

6:30 On the spherical mirror, is the hottest point at the base or the top of that line?

[@thomasmaughan4798]

Nearer the mirror. The outer portion of the mirror will focus closer to the mirror, and being large in diameter, capture more sunlight.

[@Disappointed739]

The tric, fo the paint stripper is to leave it alone for 10 to 20 minutes. A gas forms to melt the paint. Disturb it and you disturb the process