Aluminum Foil instead of Mylar?

[bigv1976]

I think you took my post wrong BT. It was humor calling you a noob. Apparently you have not noticed that I quite frequently speak highly of you and on occasion if I cant find an answer I will mention your name to someone that may need your knowledge. The plagerism comment was that I copied and pasted an article you found on this topic and posted a well over a year ago. I am bummed you perceived my post the way you did.

 

[TaoWolf]

Pure aluminum foil yes, would be that reflective. The crap you buy in the supermarket and hence what I was referring to only has 50-65% light reflection. This is what I read from about 5 different science horti sites. Just because you can read and post a single site doesn't mean you're right. Also, ToaWolf is INCORRECT since mylar DOES NOT contain any metal and hence does not have simply "an aluminum" coating.

I'm sorry I don't follow what you are trying to say by pointing out that Mylar (a patent name of polyester/plastic sheeting) is not metallic. Mylar is not - I have pointed that out from the start. Mylar can be purchased with different coatings applied to it. One of which, the one being discussed, is aluminum.

Can you cite any legitimate source on the 50-65% light reflection claim? Can anyone cite a source stating that aluminum foil bought for home/food use is not really aluminum? I'm sure there's more than one lawyer in America that would love to find out that just one person has ever gotten ill or sick due to an allergy to a metal besides aluminum that could be found in aluminum foil...

 

[Brick Top]

Does anyone believe that a vaporized mist of aluminum applied to a plastic sheeting, Mylar, is no different than aluminum foil and would not have differing reflective capabilities?

 

[TaoWolf]

Don't give advice if you don't know what the fuck you're talking about.

There's no reason to get worked up over aluminum and waste time cursing on a public forum. If you are in disagreement, I'm more than open to hearing it. Go for it and enlighten everyone with your advice (contrary or not) on the subject and back it up.

 

[Brick Top]

I think you took my post wrong BT. It was humor calling you a noob. Apparently you have not noticed that I quite frequently speak highly of you and on occasion if I cant find an answer I will mention your name to someone that may need your knowledge. The plagerism comment was that I copied and pasted an article you found on this topic and posted a well over a year ago. I am bummed you perceived my post the way you did.

I apologize for having missed your humor. That is something that people often miss in things I post so I know it can be frustrating. Now I am guilty of doing the same with what you wrote, sorry. Please excuse this old mans error.

 

[Brick Top]

Can you cite any legitimate source on the 50-65% light reflection claim?

Often times credibility of information can be questioned. The information posted earlier about aluminum foil can be found in it's exact same form on many sites online but it can also be found in the exact same form on the Reynolds Aluminum site. That means other sites used information from Reynolds Aluminum and as you inferred earlier about the credibility of information about Mylar being questionable if it comes from Wiki or a manufacturer the reprinted information from Reynolds Aluminum should also be questioned since it came from a manufacturer.

Truly independent sources can at times be more difficult too find. So much information that appears to be independent is nothing more than reprints from manufacturers and suppliers and when a Google search will bring up a few hundred thousand hits, after about 20 or 30 pages of searching people tend to give up and just go with what they see the most and assume that means it is the most accurate.

The reflective material discussion pops up very often on every board like this. I have searched for scientific papers on the subject and what I have found are sites with such papers but every one I have found is a pay & join site for researchers and educators and call me cheap if you want but I never felt like paying so I could post a scientific paper that contained irrefutable proof. Regardless which side of the debate would have been proven to be correct, many growers will always believe what they want to believe so even if I had paid for the information some would still reject it and the never ending debate would continue.

 

[TaoWolf]

So there is no source for the 50-65% light reflection claim?

By the way, you don't need to pay to see the results for things like ASTM tests if that is what you were referring to - you have to pay if you want to read the technical aspect of how the results were obtained. An example would be:

http://www.indiamart.com/mkpetro/aluminum-foil.html

If they are claiming a 97% reflectivity with aluminum foil insulation and you want/need to know how ASTM came up with that result for technical reasons, you can go to ASTMs website (http://www.astm.org/Standard/index.shtml) and put in that code (ASTM E 40 to bring up the testing procedures and buy them. But it's not necessary to know the result which is listed with the product.

 

[Fuzzbutter]

So there is no source for the 50-65% light reflection claim?

In my original research, it seems that the light reflection percentage had been highly compared to mirrors, which absorb light more than they reflect back. More research shows that the main reason aluminum foil is not recommended for such uses as additional light reflection for plants (this is not counting hoods and bulb reflectors) is due to it's ability to conduct and reflect heat.

Ex: aluminum foil ovens made from cardboard boxes coated in aluminum foil.

Therefore, it would appear that while aluminum foil is indeed a decent reflector, it can reflect too much heat and hence burn your plants or just raise the temps quite a bit which could result in wilted and un-happy plants if you don't have a ton of fans and ventilation. Essentially, mylar reflection is purely light and does not reflect heat in the same way which is why it is more recommended.

 

[TaoWolf]

In my original research, it seems that the light reflection percentage had been highly compared to mirrors, which absorb light more than they reflect back. More research shows that the main reason aluminum foil is not recommended for such uses as additional light reflection for plants (this is not counting hoods and bulb reflectors) is due to it's ability to conduct and reflect heat.

Ex: aluminum foil ovens made from cardboard boxes coated in aluminum foil.

Therefore, it would appear that while aluminum foil is indeed a decent reflector, it can reflect too much heat and hence burn your plants or just raise the temps quite a bit which could result in wilted and un-happy plants if you don't have a ton of fans and ventilation. Essentially, mylar reflection is purely light and does not reflect heat in the same way which is why it is more recommended.

I have to ask, what is 'mylar reflection'?

----

Actually, I'm done. It's the internet and this is a marijuana growing forum filled with growing mythology that has been recycled since the 70s.

If anyone wants to believe that the Mylar they see in grow tents and emergency blankets is some sort of new magical space age material and not simply plastic with a covering of aluminum - so be it. I made my case, and no hard feelings on my end at this point so I'm out.

 

[Fuzzbutter]

I don't know, I just know that's what I read. I'm not a scientist. All I know is it has to do with how light produces different wavelengths and which ones are reflected and such.

 

[GreenNerd420]

Light reflection for plant growth involves more than just reflection. You have to consider light diffusion. You also have to consider if all light spectrum rays are equally reflected or not. When you do that you find that aluminum foil makes a poor reflective material for growing plants.

Some growers confuse the light reflection percentage of a reflective material as being the only way to gauge if it is a good choice or not. What people need to consider is if the material is highly efficient at specular or diffuse reflection of light. A mirror is extremely reflective but it is specular reflection and specular reflection is not good when it comes to growing. Diffuse reflection is what is important in growing. You cannot look only at percentage of reflectivity.

Reflection for plant growing goes beyond just bouncing light rays off a surface. You need an equal diffusion, an equal distribution of not only light rays as seen by the human eye but also those of the different color spectrum that plants need that the human eye is less sensitive to. Some materials that are highly reflective to light rays the human eye is most sensitive too will absorb a percentage of other light spectrum rays.

Another thing to consider about aluminum foil is that not all aluminum foil is made from the same grade aluminum. High grade aluminum will reflect more light than low grade aluminum. It is just like high grade or low grade reflective hoods. Just because each is made of aluminum does not mean they are equally reflective or equally efficient at reflectivity of light.

If someone wants the most success possible they should not look for ways to save a nickle here and a penny there on things that are important. If someone sticks with known high grade reflective materials they will always be better off than going the ghetto grow route.

Yes. That is what I had meant to say. I think I found a new friend. I need to quit writing when I'm baked.

 

[guy incognito]

I'm confused now. Seems like reputable people on both sides spittin facts. I too wish I could independently verify any of this information.

 

[Spanishfly]

the main reason aluminum foil is not recommended for such uses as additional light reflection for plants (this is not counting hoods and bulb reflectors) is due to it's ability to conduct and reflect heat.

Surfaces that reflect visible light also invariably reflect radiant heat - infrared radiation. They are both in a narrow band of the electromagnetic spectrum.

 

[Spanishfly]

Proof of the pudding for me is that I have been using aluminium foil as a reflective material for use with tomatoes, cacti, grapes and MJ for many years with none of the mythical problems mentioned above.

Aluminium foil is also dead cheap and available everywhere.

So if you want to use it do something that is obviously rare in these forums, just have a go and try for yourself.

 

[TaoWolf]

I'm confused now. Seems like reputable people on both sides spittin facts. I too wish I could independently verify any of this information.

It's not confusing as soon as you realize that Mylar is a humble sheet of plastic and it is the humble aluminum layer that can be added to one surface that is actually reflective. All the tangents about PAR, diffuse vs. specular lighting, quality of aluminum, etc. are just tangents. All those tangent qualities can/are found in the aluminum used on Mylar (usually diffuse), emergency blankets (usually specular), plain aluminum foil (both diffuse or specular depending on the side used), reflective insulation for your home (specular), your grow light hood (specular) etc... they all carry the same testable and measurable reflective qualities and they all work due to them all being the same thing... aluminum.

Instead of this kind of attempted apple to oranges arguments through voodoo logic, it is really an apple to apple comparison that comes down to splitting hairs and confusion in order to continue.

And 'mirrors' are made of different types of reflective material, so it's pointless to compare mirrors to aluminum. Even mirrors that are made with polished aluminum are simply not as efficient because they have a layer (or more) of glass over the reflective material. Glass absorbs light and light has to pass through it twice in order to be reflected - hence it is not as efficient at reflection as the reflective material would be by itself.

 

[[email protected]]

GO with panda paper it is 90% reflective and is way cheaper than mylar..

mylar is 95% reflective but is about 17 cent a square foot (only 2 mil)--->http://www.amazon.com/Hydrofarm-Millimeter-Mylar-Feet-48Inch/dp/B000VFW7VO

Panda paper is 90% reflective but only 7 cents a square foot (a whopping 6 mil) ---->http://www.growwurks.com/black-and-white-poly-panda-film-6-mil-10-x-100.aspx

and give some rep where rep is due

HOPE I HELPED AND GOOD LUCK

oh and most hydro stores sell panda by the foot it is completely lightproof and never makes hot spots. i covered my whole room with it and it looks pretty damn clean wouldn't
change for nothin. check it out in my signature l
l
l
l
V

 

[Spanishfly]

And 'mirrors' are made of different types of reflective material, so it's pointless to compare mirrors to aluminum. Even mirrors that are made with polished aluminum are simply not as efficient because they have a layer (or more) of glass over the reflective material. Glass absorbs light and light has to pass through it twice in order to be reflected - hence it is not as efficient at reflection as the reflective material would be by itself.

I have a bit of astronomical kit, a star diagonal, which uses a front-surfaced mirror - the manufacturers claim a reflectivity of 99.9%. And of course the main mirror in my Maksutov-Cassegrain reflector is coated with aluminium - because it is a highly reflective and dead cheap metal.

 

[thewinghunter]

i used alum foil in veg room and the corner plants got HUGE in every instance... corse i did NOT bend the foil so it was perfectly flat and didnt create hotspots... i got mylar now.. and it kinda sucks... and once it bends you can see thru it... its weird like the coating comes off..

i recommend white walls...

 

[TaoWolf]

GO with panda paper it is 90% reflective and is way cheaper than mylar..

mylar is 95% reflective but is about 17 cent a square foot (only 2 mil)--->http://www.amazon.com/Hydrofarm-Millimeter-Mylar-Feet-48Inch/dp/B000VFW7VO

Panda paper is 90% reflective but only 7 cents a square foot (a whopping 6 mil) ---->http://www.growwurks.com/black-and-white-poly-panda-film-6-mil-10-x-100.aspx

and give some rep where rep is due

HOPE I HELPED AND GOOD LUCK

oh and most hydro stores sell panda by the foot it is completely lightproof and never makes hot spots. i covered my whole room with it and it looks pretty damn clean wouldn't
change for nothin. check it out in my signature l
l
l
l
V

I bought a bunch of panda film for an earlier project and I still end up using it all the time (just made some temporary covers for my net cups with little seedlings in them and used some more for added insulation and light proofing around some DWC buckets, also use it to protect the carpet when I do reservoir changes and what-not. It is easy to work with, easy to clean... And it's cheap. I dig it.

 

[TaoWolf]

I have a bit of astronomical kit, a star diagonal, which uses a front-surfaced mirror - the manufacturers claim a reflectivity of 99.9%. And of course the main mirror in my Maksutov-Cassegrain reflector is coated with aluminium - because it is a highly reflective and dead cheap metal.

Considering the topic being into astronomy, might appreciate this quick read I just stumbled on:

http://www.sti.nasa.gov/tto/spinoff1997/hm2.html