Tinfoil Myth or Fact?

true

Active Member
LMAO this thread just got way more interesting thanks to jcdws! Jim, the myth comment wasn't directed towards you, but nice training in those pics either way.

The purpose of this thread was just to see if tinfoil causes "hotspots," not to decide what the best reflective material is. Personally, I think white paint with a waterproof coating is best, but I'm more interested in seeing a picture of tinfoil burn, since that was the whole purpose of this thread. I don't care if the logic behind it is fallacious, I just want proof that "hotspots" exist, as many people have used and most likely will continue to use tinfoil in the grow room for various reasons. If you'd like to make a thread about your favorite reflective material, be my guest, but this one is about busting a potential myth. Thanks!

Again, if anyone has a pic of tinfoil burn, personally I have yet to see a tinfoil burn, so it would be appreciated.
 

dahamma

Well-Known Member
I doubt that you will find find pics of foil burn. It seems like everyone has stocks in mylar
 

d0iscar3u

Member
i got my setup coverd with tinfoil and its doing fine only usen cfl's not sure to much heat from say a 400w hps or mh bulb would prob keep to much heat in thus causeing the leaves / buds to burn not sure tho so far everything looks good ive ben usen tinfoil for 5 weeks now its doing fine
 

FilthyFletch

Mr I Can Do That For Half
aluminum foil has bad rfefledctive qualities as a big reason as you can get mylar rolling paper for as buck a roll at most dollar stores. It usually colored on the top and shiny looking but turn it over its plain silver mylar usually 3 feet wide by 8 feet long for a buck. Not as good as designed 3 mil mylar but pretty good for a buck. i have posts on this tuff if you want to search.The easiest way to show the hot spot issue with aluminum foil is with a refractometer showing different heat temps at different points ona plants. Its like glass. just because sun goes through it doesnt mean its real hot. Now tilt the glass and bend it to concave and you focus the light to a small spot like a wrinkle in tin foil. Granted if your using little cfls it wont hurt as they dont give much light but in a HID light its very easy to concintrate a beam to a leaf and burn it. i will look for pictures maybe make a video with a refractometer showing uneven heat
 

Siddhartha

Well-Known Member
Tin foil is plenty reflective. It's slightly more reflective than a flat white wall. When you see your reflection in a sheet of tin foil,.. you're looking at reflected light in the visible spectrum. It also reflects slightly more of the spectrum than a white wall.

Mylar is more reflective. Aluminum is porous on the microscopic level, which is why it takes to anodizing, and why it's less reflective than mylar. MOST light fixtures use aluminum as a reflector,.. the reflectivity of tin foil is the same because it's the same material.

It IS possible to create a concave mirror with tinfoil and concentrate the light of say a circle of 20 inches across into a spot that's a quarter inch across. You'd need a parabolic mirror/bowl to do this though,.. and I might guess that amount of light would burn a plant. Don't ask me how small the reflective area would have to be to burn a plant, but it may be smaller than you think under 1000 w of light.,. which is where the stories may have started.

Most people's problems I've seen with tinfoil, are just laying the blame where it doesn't belong. There are other things that create burnt spots such as Lights too close,.. underwatering,.. ,.. as well as incorrectly feeding nutes. If you notice,.. the average diagnosis for grow problems, is wrong. Got tin foil in your grow,.. got burnt spots on some plants near the edge/wall.. easy diagnosis.

One reason why you don't want to use tin foil in a grow area,.. it conducts electricity. contact a corner of a sheet into a light socket,.. and another corner of the sheet against a plug or exposed wire,.. and you've got a shorted circuit or worse, it could potentially heat up and cause a fire. If you don't have exposed plugs/wires, and sockets in your grow,.. and you make sure to lay the foil flat, it's as good as painting the walls white as far as reflectivity, if not better.
 

true

Active Member
Tin foil is plenty reflective. It's slightly more reflective than a flat white wall. When you see your reflection in a sheet of tin foil,.. you're looking at reflected light in the visible spectrum. It also reflects slightly more of the spectrum than a white wall.

Mylar is more reflective. Aluminum is porous on the microscopic level, which is why it takes to anodizing, and why it's less reflective than mylar. MOST light fixtures use aluminum as a reflector,.. the reflectivity of tin foil is the same because it's the same material.

It IS possible to create a concave mirror with tinfoil and concentrate the light of say a circle of 20 inches across into a spot that's a quarter inch across. You'd need a parabolic mirror/bowl to do this though,.. and I might guess that amount of light would burn a plant. Don't ask me how small the reflective area would have to be to burn a plant, but it may be smaller than you think under 1000 w of light.,. which is where the stories may have started.

Most people's problems I've seen with tinfoil, are just laying the blame where it doesn't belong. There are other things that create burnt spots such as Lights too close,.. underwatering,.. ,.. as well as incorrectly feeding nutes. If you notice,.. the average diagnosis for grow problems, is wrong. Got tin foil in your grow,.. got burnt spots on some plants near the edge/wall.. easy diagnosis.

One reason why you don't want to use tin foil in a grow area,.. it conducts electricity. contact a corner of a sheet into a light socket,.. and another corner of the sheet against a plug or exposed wire,.. and you've got a shorted circuit or worse, it could potentially heat up and cause a fire. If you don't have exposed plugs/wires, and sockets in your grow,.. and you make sure to lay the foil flat, it's as good as painting the walls white as far as reflectivity, if not better.
Thats pretty much what I've thought as well. The other legit reason I hate tinfoil is because its just too noisey if a fan blows on it.

Thanks for the replies.
 
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