Can i use foil as a mylar substitue? pics included

nah, foil turns light energy into heat energy easily.

get some poster board, flat white paint etc.

I don't think a lot of people understand how this works. You can tell if something is a good reflector just by going "Ooo that's shiny!" I can't stand when people try to say mirrors absorb light (this just proves my point that a lot of people really don't understand shit about what they're doing.) they don't absorb light, they just do not disperse the light whatsoever. Foil does not turn light into heat, it conducts heat very well though, which would mean your walls of your box getting hot. If it's not a dark color, it's not turning light into heat, if it's god damn silver it's turning almost none into heat energy.

I've always thought the theory that foil caused hot spots and burned plants was BS. I used foil for many years and never had problems, but granted I was not using the high powered HID lights that are out there today. I could well be wrong. Switched to mylar a few years back and love that stuff.

AimAim said:

I've always thought the theory that foil caused hot spots and burned plants was BS. I used foil for many years and never had problems, but granted I was not using the high powered HID lights that are out there today. I could well be wrong. Switched to mylar a few years back and love that stuff.

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I never knew what hot spots meant and now that you explained it, it does sound like bs. Foil is a very good conductor of heat, that's why you can have it at 400 degrees in the oven and remove it by the foil and not burn your hands. I would think that the mylar (aka the material used for emergency blankets) would cause these so called hot spots. If you were to wrap up in aluminum foil in the cold you would freeze your ass off.

The arguments against Aluminum Foil never made sense to me, and I don't like to go around telling people what to do.
so take this with a gram of 30-10-10...haaaaa... I'd like to say...
I use aluminum foil... There I admit it. I use it like wall paper on my grow room walls...
I have installed a couple of thousand light fixtures in my life, and 99% or them use a aluminum reflector as the light back...
Aluminum reflects light...so tell me why you don't want to reflect any of your extra light that hits your walls?
Maybe if you have a 1000 W MH/HPS then no aluminum foil...
I use heavy duty/wide foil BTW...

Sand4x105 said:

The arguments against Aluminum Foil never made sense to me, and I don't like to go around telling people what to do.
so take this with a gram of 30-10-10...haaaaa... I'd like to say...
I use aluminum foil... There I admit it. I use it like wall paper on my grow room walls...
I have installed a couple of thousand light fixtures in my life, and 99% or them use a aluminum reflector as the light back...
Aluminum reflects light...so tell me why you don't want to reflect any of your extra light that hits your walls?
Maybe if you have a 1000 W MH/HPS then no aluminum foil...
I use heavy duty/wide foil BTW...

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I think, and I'm far from an expert, that their reasoning for the hotspots is in the way that the foil bends and reflects the light differently wherever it bends. But I use it to cover net-cups in my hydro system...

I hear 2 contradictory stories about foil:

One guy says the foil warps and bends concentrating light like a magnifying glass and will set the plant on fire.

Next guy says don't use aluminum foil as it reflects next to nothing.

Whatever.

AimAim said:

I hear 2 contradictory stories about foil:

One guy says the foil warps and bends concentrating light like a magnifying glass and will set the plant on fire.

Next guy says don't use aluminum foil as it reflects next to nothing.

Whatever.

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My apologies, The [MY] foil isn't very reflective.. More than black painted metal, but not as much as mylar (I haven't used mylar in the past for growing, but I'm familiar with it). I just use it to block light going into net-cups.

NotParanoid said:

My apologies, The [MY] foil isn't very reflective.. More than black painted metal, but not as much as mylar (I haven't used mylar in the past for growing, but I'm familiar with it). I just use it to block light going into net-cups.

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No reason to apologize, I wasn't talking about your or any one else's comment in this thread. Just saying I've heard these 2 conflicting arguments many times..

The Red said:

I don't think a lot of people understand how this works. You can tell if something is a good reflector just by going "Ooo that's shiny!" I can't stand when people try to say mirrors absorb light (this just proves my point that a lot of people really don't understand shit about what they're doing.) they don't absorb light, they just do not disperse the light whatsoever. Foil does not turn light into heat, it conducts heat very well though, which would mean your walls of your box getting hot. If it's not a dark color, it's not turning light into heat, if it's god damn silver it's turning almost none into heat energy.

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If it's a typical mirror (see: things you'd normally find in your house) - I have to disagree, they do absorb light.. in mass quantities. You'd need a dilelectric mirror with multiple layers of dielectric material, effectively forming a coating.. to get anywhere near 99.9%+ of the light reflected - anyway.

I think the disadvantage of foil is it folds and crinkles easily. The folds can reflect the light unevenly and that is a hot spot. I've used it before and never had a problem though. I prefer Mylar cause its thicker, comes in wider sheets and is easier to install

I guess mylar could work, still have hotspot potential... and you have to be -very- careful when doing foliar spraying.. any drops on it will leave discoloration/stain-like marks and white paint is much easier to handle, or re-do.. alternatively, you could also use Panda Film, which works great for dividing part of a room off and keeping light out.. white on the inside, black on the outside.

Figong said:

I guess mylar could work, still have hotspot potential

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Exactly, I've got folds and wrinkles in my mylar and can see bright spots on the plants where it is focusing light but have never experienced burning.

bmeat said:

nah, foil turns light energy into heat energy easily.

get some poster board, flat white paint etc.

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This Guiy IS The Worst Person YOU Could EVER Tack any Advice From ~ Look at his GROW jorn. There a Joke
Its worth a Look Just for The Laugh!

LOL...the Hanson brothers loved their tin foil

Nol is speaking about bmeat

Nol said:

This Guiy IS The Worst Person YOU Could EVER Tack any Advice From ~ Look at his GROW jorn. There a Joke
Its worth a Look Just for The Laugh!

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See my sig?

I just mentioned to someone else about getting mylar if you don't have any available. Even if you can't get emergency blankets.
As a stoner I'm sure you eat chips. If you don't your friends do. Ever look at the inside of a bag of chips? Yep, that's mylar. slit them down the side and before you know it your munchies have mylared your room.

Oh yeah. Don't use foil. Not only is it not as reflective as just plain white paint, it also makes your grow look soooooooooo ghetto. Even more ghetto than chip bags turned inside out.

Ok, as some of you know, im a nerd and i know my universe and electro-chemistry.

When im building circuits, i solder with tin/silver + rosin core, it is a fantastic conducter as it has MINIMAL RESISTANCE.

Now alluminium is equally a fantasic conducter as it also has minimal resistance, this means its able to transfer heat and energy very effeciently, I have over 294 CFM of true airflow. I change my air approx 6 times every minute.

Black pond plastic has a HUGE resistance, (electricty and heat are trapped and cannot move through it), meaning it has bad heat transfer efficency.

This would deduce logically, to alluminum being a better solution then black pond plastic, as alluminum provides a basic level of relections and SUPERIOR heat dissapation, (it hold heat for a shorter time, its able to cool faster).

This is called "sinking heat", think about the heatsink in your computer. The alluminimum foil absorbs the heat on the top of the res, it reflects back what unused energy its able to, and the excess heat is dissapated by my ample air flow.

This would logically dictate to me, that foil would be the superior material as apposed to black plastic.

Eventually i will line everything in mylar, but as ive just over extended my budget to get my grow room active, it will be a month or so before i do so.

Further, to the dipshit who "ROFL'd on the floor", when they saw the pictures of my grow room, i find that a little insulting. Please advise as to what you found so funny? Id appreciate feedback instead of ridicule. Congrats you just made it to number 2 on my shit list.
Behind bmeat, but definently a bigger tool then fresh 2 de@th.

and just for people saying white is better etc etc. please read and look at photos.

IM ASKING.. BLACK PLASTIC OR FOIL! ONE OR THE OTHER.