Instructables

Mirror Paint?

I am trying to make a death ray with a parabolic mirror. I have tried a mylar space blanket but it wasn't smooth/reflective enough to make a concentrated beam that burnt anthing. I was wondering if there was any such thing as mirror paint. by this I mean a highly reflective paint. If anybody knows about this or has any other reflective ideas I would apreciate it.

Thanks.

Kiteman2 years ago
What have you made your parabolic surface from?

A mylar film should be reflective enough if it is focused properly, so maybe your dish is not so accurate?
nurdee1 (author)  Kiteman2 years ago
In used an old 2-3 foot satellite dish as a parabolic mirror. I think my dish is accurate but I couldn't get my Mylar on very well because all I did was put on silicone and then smoothed it the best I could. Is there a better way to do this? Can you give me instructions.

Thanks
Kiteman nurdee12 years ago
As frilled says, the secret is a vacuum.

Seal all the holes in the dish (paint with epoxy?) and then drill one hole to match whatever plumbing you have.

Lay your sheet of Mylar over the dish and glue it around the edges. Make sure the seal is air-tight and continuous.

Using the plumbing connection, apply a vacuum to pull the Mylar into the right shape, seal off the plumbing connection and you're done.

~or~

There are online calculators that will work out templates for making parabolas from flat materials. Use one to produce templates for a parabola that matches your dish, cut out pieces from your Mylar, and then carefully glue them to your dish.


perhaps a combination of the two; spray adhesive, dried to tack (permanent seal), then applying the mylar with a full vacuum to press it evenly to the surface of the existing dish would be great.
Kiteman Kiteman2 years ago
Dopey iPod automatic spelling-corrector!

That should say "as frollard says".
;)
agree 200%. Mylar is commonly used as an EXTREMELY accurate mirror, and for parabolics, you just have to seal the edges and draw a vacuum behind it, you'll have a mathematically very accurate parabola.
Dude, I think you need to change your avatar. "Frilled, Frollard, it's all the same..."

http://en.wikipedia.org/wiki/File:Chlamydosaurus_kingii.jpg

(See Kiteman's comments above...)
bwaaaaaaaaahahahahaha

Unfortunately I've used this avatar so long it's stuck, and still unique, frilled I'm afraid would I'm sure be duplicated everywhere.
dlyttle1 year ago
I tried a low cost method of using spray adheasive on a 6 foot solid dish then applying aluminum foil, shiny side up. It looked awful with lots of wrinkles but with full sun I got enough heat to burn a dark piece of cloth to ashes. My infrared thermometer topped out at 440 degrees F.

I plan to try the Mylar technique next...

By the way (and I am surpirsed no one else has asked) why do you want to make a "Death Ray?" The focal point is so low in the dish the victim would have to be inside it to feel any heat.
Prfesser2 years ago
FWIW I saw a can of mirror paint yesterday, in the paint section of Hobby Lobby. I have no idea how well it works but (A) it was expensive, I think $12 a can, and (B) it only makes second-surface mirrors. That is, the "inside" surface is reflective, the "outside" exposed to air will have a matte look. HTH
rickharris2 years ago
Try this with your mylar film.

Make a frame to trap the mylar with an open circular front.

Trap a sheet of mylar under the frame rather loosely - The suck out the air from the back - A vacuum cleaner should do. this will cause the mylar film to form a smooth parabola.
nurdee1 (author)  rickharris2 years ago
How would I do this with a 2-3 foot parabolic satellite dish.
Seal mylar to the edge and pull air out from the middle. I can't see you dish or know what skills/facilities you have so I can't do better than that. Sorry
AndyGadget2 years ago

An alternative to a parabolic mirror is to use many small separate mirrors, each one reflecting the sun towards the same point.  There's an example of the concept HERE. The base-plate that the mirrors are attached to doesn't have to be parabolic, and can be as large as you like.  HERE are instructions on how to build one.
nurdee1 (author)  AndyGadget2 years ago
This is a nice idea but since I already have a 2-3 foot satellite dish I would like to do this with the parabolic dish.

Thanks for your thoughts.
 
Fair enough, but if the paint or mylar ideas don't work there's always this option, using the dish as a base like they do in the video.
Vyger2 years ago
They don't paint mirror surfaces because they would never be reflective enough. For you everyday common ones they "silver" them on the back side. What that means is that they are coated with a thin film of reflective metal. It used to be silver but now I believe they use mostly aluminum. For large optical mirrors, like what you are talking about, they are coated on the front side after the glass has been polished. They use a special process, done in a vacuum and using atomized aluminum. The aluminum forms a extremely thin coating on the polished glass surface. It is not something that you could do at home.

Did yo check the ideas that others had had?

http://www.instructables.com/id/Parabolic-solar-ray-gun-a.k.a-solar-death-ray/

Mythbusters explored this type of thing in one of their recent episodes.

If you are trying to concentrate sunlight you would need a pretty large mirror to accomplish anything.

If your using some other light source it would have to be extremely high powered to produce enough light to even just make something warm.
nurdee1 (author)  Vyger2 years ago
I saw the myth busters episode, in fact that it what inspired me. So if there is no mirror paint how could I do this. Would I be better to use a whole bunch of tiny mirrors or try to vacuum press on a piece of Mylar.

Thanks for helping.
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