Okay -- exactly how does aluminum foil create "hot spots" anyway?

CheapJoe

Member
What Reflective Materials can I use for my Grow Room?
[HR][/HR] Aluminum Foil:
Aluminum foil is no more than 55% reflective - if used, make sure that the dull side is the one that is used to reflect the light. When it becomes creased its reflectivity is even lower (around 35%.) It is also very dangerous to use because it creates hotspots easily, is electrically conductive, and is a fire hazard when it is in close contact with HID lighting. Attaching this to walls is a pain and usually using aluminum tape or glue is the best way. This should only be used as a last resort, and even then its usefulness is questionable.

ok so just because its stupid to judge something based on one article; I found this on wiki...

"
Aluminium foils thicker than 25 µm (1.0 mil) are impermeable to oxygen and water. Foils thinner than this become slightly permeable due to minute pinholes caused by the production process.
Aluminium foil has a shiny side and a matte side. The shiny side is produced when the aluminium is rolled during the final pass. It is difficult to produce rollers with a gap fine enough to cope with the foil gauge, therefore, for the final pass, two sheets are rolled at the same time, doubling the thickness of the gauge at entry to the rollers. When the sheets are later separated, the inside surface is dull, and the outside surface is shiny. This difference in the finish has led to the perception that favouring a side has an effect when cooking. While many believe that the different properties keep heat out when wrapped with the shiny finish facing out, and keep heat in with the shiny finish facing inwards, the actual difference is imperceptible without instrumentation.[SUP][9][/SUP] The reflectivity of bright aluminium foil is 88% while dull embossed foil is about 80%.[SUP][6]"




source:

[/SUP]
^ [SUP]a[/SUP] [SUP]b[/SUP] Hanlon, J. (1992). 1st ed. Handbook of Package Engineering, Lancaster, PA and Technomic Publishing: ISBN 0-87762-924-2. Chapter 3 Films and Foils.






Guess what, FOIL WORKS FINE!

I hope that info wasn't off a manufacture's site.
 

shmrck420

Member
Im not downing anyones opinions in this thread.....but i have a very small grow space about 2ft wide 2ft diam, and four foot high, with aluminum foil and t5 HO cfl's. My plants are healthy and not once been burned, in flowering now and doing great!
 

GreatwhiteNorth

Global Moderator
Staff member
Im not downing anyones opinions in this thread.....but i have a very small grow space about 2ft wide 2ft diam, and four foot high, with aluminum foil and t5 HO cfl's. My plants are healthy and not once been burned, in flowering now and doing great!
I don't think you're going to burn with CFL's - but the whole point is a decent flat white paint job on the walls will do a heck of a lot better job.
 

PeyoteReligion

Well-Known Member
With low wattage I don't see it as a problem. I grew with a 400 watt my first grow in a closet with tin foil on the walls and had no leaf
burn or anything even close. With that being said I can see the concept in how it could burn leaves with a higher wattage bulb possibly.
 
Top