Mylar
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TeaTreeOil
Well-Known Member
If your Aluminized Mylar is superior at reflecting visible light(400-700nm wavelengths), then it is also superior at reflecting infrared(or IR, which is 700-10,000 nm wavelengths, roughly). This depends on the thickness of the aluminum deposit.
Mylar isn't really reflective without an aluminum metalized coating(PET/Mylar is actually semi-transparent without pigments, or coatings). This means a microscopic layer of aluminum on plastic fiber is completely responsible for the reflectivity of reflective(Aluminized) Mylar.
Radiant heat and radiant visble light are both electromagnetic waves. In layman's terms electromagnetic waves are often called light waves(or radiance, as in radiation). These 'hot spots' are created by (IR) invisible light.
Aluminized Mylar is only maximally 91%, maybe 92% reflective with visible light. It averages about 90% between 400 and 700 nm wavelengths, slightly less than an aluminum-surfaced mirror. Mainly due to thickness. However, Aluminized Mylar can be upto 98% reflective with IR light.
Most foils can't match thick aluminized mylar in terms of specular reflectivity. Typically Al foils are between 80-90% reflective with visible light(yea, even the Reynold's wrap in your kitchen, which is 98.5% pure Al). And up to 97% reflective with IR light. Which side you use makes a nearly insignificant difference.
Mylar isn't really reflective without an aluminum metalized coating(PET/Mylar is actually semi-transparent without pigments, or coatings). This means a microscopic layer of aluminum on plastic fiber is completely responsible for the reflectivity of reflective(Aluminized) Mylar.
Radiant heat and radiant visble light are both electromagnetic waves. In layman's terms electromagnetic waves are often called light waves(or radiance, as in radiation). These 'hot spots' are created by (IR) invisible light.
Aluminized Mylar is only maximally 91%, maybe 92% reflective with visible light. It averages about 90% between 400 and 700 nm wavelengths, slightly less than an aluminum-surfaced mirror. Mainly due to thickness. However, Aluminized Mylar can be upto 98% reflective with IR light.
Most foils can't match thick aluminized mylar in terms of specular reflectivity. Typically Al foils are between 80-90% reflective with visible light(yea, even the Reynold's wrap in your kitchen, which is 98.5% pure Al). And up to 97% reflective with IR light. Which side you use makes a nearly insignificant difference.
tilemaster
Well-Known Member
I dont think mylar is gonna wrinkle, combust or ne thing. They wouldnt sell it if it wasnt tryed and proven for horticulture apps with heat. Plus it should ever be exposed to heat over the mid 90's unless u put the shit in a oven
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TeaTreeOil
Well-Known Member
Take a lighter and hold it to reflective mylar for a few seconds. Looks, it ignites, and starts [/b]burning itself! No more lighter required. It supports flame!
Say your adhesive tape fails... a corner gets close enough to a HID lamp.... Say good bye to your grow room, house, whatever.
Take a propane torch and attempt to ignite aluminum foil. Won't happen. It'll melt perhaps... but it doesn't support flame.
Say your adhesive tape fails... a corner gets close enough to a HID lamp.... Say good bye to your grow room, house, whatever.
Take a propane torch and attempt to ignite aluminum foil. Won't happen. It'll melt perhaps... but it doesn't support flame.
tilemaster
Well-Known Member
teatreeoil, fk man now u even got me trippn bout startin a fire fucker. Thanks may have actually saved me from a potential fire. I have my mylar ducktaped to poly since the poly is effectively my wall attached right to the framing, so the mylar is duct taped direct to poly. I went st8 out to depot and got a fire suppressor, and I will staple gun mylar to studs behind the poly. Even tho Im hating on your al foil, good looking out for all of us stoners that hung mylar with TAPE
marni3d
Well-Known Member
The mylar i use is diamond reflective, it costs more but its well worth it and you can get it for cheap on ebay!
My mylar:
The ultimate reflective sheeting
Diamond Reflective sheeting is a premium reflective sheeting which has all the reflective qualities of Mylar but with more even light distribution due to the diamond pattern. 100% Lightproof, Diamond Sheeting is flame retardant, easier to handle and much more resistant to creasing than other types of reflective sheeting. Also, uniquely the reflective metal layer is sandwiched behind a clear protective PET film that protects against heat, humidity, moisture and handling. Sold off the roll in any length by 1.4 metre widths.
I just put a lighter to it and it didnt catch fire! after reading that i just had to test it - a corner was near the hps light! but i duck tapped it all up now! hehe
Silky Shagsalot
Well-Known Member
^^^that's astro-foil^^^
RandyRocket
Well-Known Member
My Mylar
Gift wrap paper at dollor store.
chip/snack bags inside can be Mylar.
Mylar Ballon.
Collector card (Magic the Gathering, baseball card, pokeman card) inside can be Mylar.
Flower arangement have Mylar to cove the pots. Color one side shiny the other. (Cemitary trash after Vet day, memorial day, deaths the caretakers throw it out after a week in large citys if you ask they will give you goobs). also the pots.
Granola bars.
Gift wrap paper at dollor store.
chip/snack bags inside can be Mylar.
Mylar Ballon.
Collector card (Magic the Gathering, baseball card, pokeman card) inside can be Mylar.
Flower arangement have Mylar to cove the pots. Color one side shiny the other. (Cemitary trash after Vet day, memorial day, deaths the caretakers throw it out after a week in large citys if you ask they will give you goobs). also the pots.
Granola bars.
TeaTreeOil
Well-Known Member
I'd suggest lighting sheet. It's aluminum sheet metal with top-of-the-line reflective coatings(dielectric, usually, which last 20+ years). Usually around 95% effective with visible light.
yelodrvr
Well-Known Member
where would you find that at.
same material in the back drops used in still photography or portraits, correct?
DownOnWax
Well-Known Member
Yes and it is 6 Mil which is A LOT easier to work with.
Or you can paint your walls white but will not work as well. I did however go against my old thinking and ordered some 4 mil Mylar because I go it so damned cheap.
1 Mil BLOWS!!!
cadillacjack81
Well-Known Member
how bout flat white paint
just crazy enough to work
just crazy enough to work
RandyRocket
Well-Known Member
I think 9 out of 10 time flat white is best. cheap, fast to put up/dry, easy to find (any paint store)
Paint it flat white first. Then go back and throw money at it to make it shinny.
TeaTreeOil
Well-Known Member
Just Google "lighting sheet". It comes in many forms, from textured and white(enamels/powder coat, typically) to smooth, bright, and highly specular polished metal(almost always aluminum).
It is sheet used specifically for light reflectors, and more specifically the walls, so that light is not wasted. It comes in various forms. Usually cheaper, less efficient sheet is used for walls. And the higher quality sheet is used for internal reflectors.
It's basically just aluminum sheet metal. There's not really a big difference between regular Al foil and the highest end aluminum reflectors. About 11-14% maximally(400-700nm wavelengths exclusively), comparing ideal surfaces. The main benefit is durability(decades), and consistency, as normal aluminum oxide(tarnish) affects the spectral reflectivity somewhat unevenly, but is a constant decay across the spectrum. Though, this still takes years to become significant, and you can always clean and polish the surface back to like-new.
Depending on the specific coating(s), can greatly change lighting sheet UV(ultraviolet) and IR(infrared) reflectivity. Sometimes for the better, sometimes not. UV is somewhat useful for plants(more so for flowering). If you include some of both of these regions, say 350-750nm wavelengths, then lighting sheet could be over 20% superior to regular aluminum surfaces, or much less, depending on the coating(s).
Mylar films are also, sometimes, used for window tinting, usually with metallic microscopically thin reflective coatings(often tin, Sn, a white metal, as it's a great visible light reflector, near-visible UV and IR not so much).
Tin metalization(Mylar aka polyester aka PET, or nylon films) is how you can keep your privacy, but allow radiant heat in and out, and is often used in films for homes and cars when this is desired.
They also create microscopically thin aluminum films that pretty much block everything(radiance) just about equally(+/- 10%, roughly). With varying degrees: 10%, 30%, 60%, and even over 90%. The thickness of the metalization determines this.
Other metals, and other compounds can be used to fine-tune what(radiance) is blocked and what's not.
I bring all that up because you should understand that the thickness of your reflective(aluminized) Mylar is crucial to the effectiveness of reflectivity. The thicker, the better. Which is why I really like sheet aluminum.
White paint is decent for lumen measurements. Not so great for PAR measurements. My 2 cents.
peaceb2usall
Well-Known Member
Where would you find this in the US at a good price or canada?
peaceb2usall
Well-Known Member
Where did you find this 'so damn cheap' 4 mil Mylar?
BigVape
Well-Known Member
Hit up ebay, 34" by 50' 5 mil mylar for dirt cheap. I got it for about 30 dollars shipped.
http://cgi.ebay.com/reflective-Thick-Mylar-metalized-plastic-5-Mil-34"-50ft_W0QQitemZ370280954996QQcmdZViewItemQQimsxZ20091027?IMSfp=TL091027209004r7127
Mr Bomb
Active Member
The best place to buy Mylar is either at your local hydro shop or online. It is traditionally used to reflect the light in your grow room and is best used to cover all walls in your growroom including the ceiling.
wakebakeworksleep
Member
I know this thread is old but I had to reply after reading your IDIOTIC comment.
Aluminum foil? Really? Even a newbie knows NOT to use al foil.
It's barley 50% reflective and this is only in the case where it is completely flat. Even when flat it will create hot spots due to the other ingredients other than aluminum.
Who uses AL? People who don't know SHIT about grow rooms, that's who.
Mylar, even when not completely flat, is over 90% reflective and just as cheap as AL. It only needs to be cleaned or replaced once a year if the grow room is reasonably clean and taken care of.
If BAD ADVICE is your thing, you're doing a GREAT job!
Aluminum foil? Really? Even a newbie knows NOT to use al foil.
It's barley 50% reflective and this is only in the case where it is completely flat. Even when flat it will create hot spots due to the other ingredients other than aluminum.
Who uses AL? People who don't know SHIT about grow rooms, that's who.
Mylar, even when not completely flat, is over 90% reflective and just as cheap as AL. It only needs to be cleaned or replaced once a year if the grow room is reasonably clean and taken care of.
If BAD ADVICE is your thing, you're doing a GREAT job!