Mirrors as Reflectors

shnkrmn

Well-Known Member
Telescopes and other precision instruments use front silvered or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have). Some of them use silver, but most are aluminum, which is more reflective at short wavelengths than silver. All of these coatings are easily damaged and require special handling. They reflect 90% to 95% of the incident light when new. The coatings are typically applied by vacuum deposition. A protective overcoat is usually applied before the mirror is removed from the vacuum, because the coating otherwise begins to corrode as soon as it is exposed to oxygen and humidity in the air. Front silvered mirrors have to be resurfaced occasionally to keep their quality.

So here are the best mirrors you can buy (not YOU, you can't afford them) and they reflect 90-95% when new.

Yes, this is from Wikipedia. Yes, it is accurate.
 

Picasso345

Well-Known Member
Another reason they are relatively poor reflectors is you are sending your light through some thick glass - not once but twice. Scientific mirrors minimize this as much as possible, but any mirror we could lay our hands on has pretty thick glass.
 

OregonMeds

Well-Known Member
Telescopes and other precision instruments use front silvered or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have). Some of them use silver, but most are aluminum, which is more reflective at short wavelengths than silver. All of these coatings are easily damaged and require special handling. They reflect 90% to 95% of the incident light when new. The coatings are typically applied by vacuum deposition. A protective overcoat is usually applied before the mirror is removed from the vacuum, because the coating otherwise begins to corrode as soon as it is exposed to oxygen and humidity in the air. Front silvered mirrors have to be resurfaced occasionally to keep their quality.

So here are the best mirrors you can buy (not YOU, you can't afford them) and they reflect 90-95% when new.

Yes, this is from Wikipedia. Yes, it is accurate.
First surface mirrors are what I tested with. They didn't work better than flat white paint but if you want to try them anyone can afford them. Make a couple calls to places that repair or dispose of high end projection televisions. You can get all the first surface mirrors you want for free. Some of the mirrors I got for free are huge. 3'x5' industrial things that were thousands of dollars new...
 

shnkrmn

Well-Known Member
If I lined my grow space with glass there would be blood . . . .

I'm a flinger, as my wife says.

:-P
 

shnkrmn

Well-Known Member
I've been using Reflectix, which is basically bubblewrap coated with a layer of aluminum. Anyone have any thoughts on that?
 

KaliKitsune

Well-Known Member
I've been using Reflectix, which is basically bubblewrap coated with a layer of aluminum. Anyone have any thoughts on that?
Would work fine. My only concern would be the bubblewrap acting as an insulator and requiring more power for keeping temps maintained while lights are on.

Of course, it's hot where I am, even full-blast AC barely keeps the place at 80 during the summer time, so you should understand where my particular concern originates from.
 

shnkrmn

Well-Known Member
Would work fine. My only concern would be the bubblewrap acting as an insulator and requiring more power for keeping temps maintained while lights are on.

Of course, it's hot where I am, even full-blast AC barely keeps the place at 80 during the summer time, so you should understand where my particular concern originates from.
I'm in a cold place. that's part of what attracted me to it as a material. My lights on temp is under 80 even with two 600Watters.
 

shnkrmn

Well-Known Member
is it the same or like mylar?
Well, It doesn't precisely look like mylar but close. It says there is a layer of aluminum directly deposited on the plastic. It stand up on its own, which is kind of useful. You can just make a hoop of it with your plants in the middle, wrap it around a framework, pin it to stuff. It has a insulation value of R3 lol. 4' x 25' costs 25 bux. I think I saw some pix on here of the inside of a bought growtent that looked like it was lined with this stuff. . .
 
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