# DIY reflector for light housing?



## nschmitz06 (Feb 20, 2011)

I will be getting my new CFL's soon and when i looked into the top of my exo-terra hood, I realized alot of light is wasted because of the lack of reflection built in. I was going to try using aluminum tape (the kind for ducts) because it is slightly more reflective and will adhere to the metal well. Does anyone have any recommendations for other materials to use as a reflector??


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## DragonSpirit1185 (Dec 6, 2010)

lightyourreptiles.com
They have some reflector tape....
WontonSally used some in his build...
http://www.dendroboard.com/forum/be...s-all-input-advice-welcome-23.html#post630096


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## nschmitz06 (Feb 20, 2011)

Perfect, that is the aluminum tape I was referring to. I work at a mechanical contracting company and we have tons of if laying around back in the shop...  thanks dragon!


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## ryan10517 (Oct 23, 2010)

truly, flat white paint on the inside is about the best reflective material for spiral CFLs. They're pretty inefficient to begin with though. A t5 or tube bulbs are much easier to make an effective reflector, but flat white painted on the inside of the fixture produces about the best results and is really easy to do. That is what i use for all my DIY spiral CFL hoods.


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## nschmitz06 (Feb 20, 2011)

I started to look up more ways of getting an efficient reflector for growing plants and stumbled upon about 10 threads in (of course) marijuana growing websites. The discussions became pretty in depth about light reflection, diffusion and heat dissipation. The materials they used that produced about 95% reflected light and 85% reflected heat is called Foylon. It is a polyester fabric reinforced with a foil laminate. I am currently looking up some costs involved with this material and how easily it can be acquired. 

Just for reference I am not interested in what they are growing, however I would trust the forums that this material (foylon) is the best for light reflection since these people are VERY passionate about their end product. Who would of thought I'd use bud growing sites to improve upon the terrarium community? Not I


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## Dangerously (Dec 19, 2007)

The shiny tape that's used for heating & A/C ducts will work fine, and is rated for hot environments. I have some on several of my lights (it's been on for years, in fact), and it still looks brand new. I would think that for a frog viv it isn't necessary to overspend or over-think something like this.  But, it's up to you!


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## ryan10517 (Oct 23, 2010)

although it claims to have 95% reflectivity, i doubt that it will be that useful. Seeing it is reinforced with aluminum foil, the strands in there not straight. Therefore, the light that gets reflected off of it will not all go downwards into the tank like you want. Instead, it will most likely get reflected any and all directions and therefore be dissipated. Not saying you shouldn't try it, but i would be skeptical.


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## Rhesus Feist (Jan 20, 2011)

If you can get the foil tape for free, why bother spending money on the hydroponic/pot growing cloth? Go with the flat white paint or the foil tape if you really want shinny. I can't imagine the difference in PAR going into the viv would be more than a few % between the pot cloth and flat white paint.

If you want efficiency go with HO T5 bulbs with good parabolic reflectors, or better yet HO LED. Since you already have the exo-terra hood, go with flat white or the foil tape


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## james67 (Jun 28, 2008)

there is a long lasting and continuing debate, among growers using electric lights, about the effectiveness of white paint v.s. reflective material. there is a TON of info,and a plethora of inventions, and opinions out there designed to sway you towards one or the other, but if it were me (and it has, as i build the majority of fixtures over my tanks) i'd go with white paint. a spray can of flat white paint costs $0.98 and is very easily applied. if your set on using reflective material, mylar is a popular choice and is frequently found being sold by the foot at anyting from your local LFS to hydroponics shops. its inexpensive and flexible, but creases easily (creating unwanted direction of light)

james


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## ryan10517 (Oct 23, 2010)

james67 said:


> there is a long lasting and continuing debate, among growers using electric lights, about the effectiveness of white paint v.s. reflective material. there is a TON of info,and a plethora of inventions, and opinions out there designed to sway you towards one or the other, but if it were me (and it has, as i build the majority of fixtures over my tanks) i'd go with white paint. a spray can of flat white paint costs $0.98 and is very easily applied. if your set on using reflective material, mylar is a popular choice and is frequently found being sold by the foot at anyting from your local LFS to hydroponics shops. its inexpensive and flexible, but creases easily (creating unwanted direction of light)
> 
> james


totally agree james. well put!

Another option is cutting a large diameter PVC pipe in half lengthwise, then applying either the foylon or mylar to the inside with glue/silicon/whatever you have, then smoothing it out to make it parabolic and not wrinkled. I have done this before, but i find it to be more work than it's worth.


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## nschmitz06 (Feb 20, 2011)

Thanks everyone, I found the only decent foylon seller to be in Germany and with mylar being so crease-able its not worth the hassle. Its prolly not worth the extra 10% or so of light. I think ill go with the white paint! (sometimes cheap is better)


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## tachikoma (Apr 16, 2009)

james67 said:


> there is a long lasting and continuing debate, among growers using electric lights, about the effectiveness of white paint v.s. reflective material. there is a TON of info,and a plethora of inventions, and opinions out there designed to sway you towards one or the other, but if it were me (and it has, as i build the majority of fixtures over my tanks) i'd go with white paint. a spray can of flat white paint costs $0.98 and is very easily applied. if your set on using reflective material, mylar is a popular choice and is frequently found being sold by the foot at anyting from your local LFS to hydroponics shops. its inexpensive and flexible, but creases easily (creating unwanted direction of light)
> 
> james



This seems silly to have a debate about this going on for so long, can't this kind of thing be scientifically measured so there is 100% no doubt as to which one is more reflective? Or is there some reason this is difficult that no one has done it?


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## james67 (Jun 28, 2008)

the argument isnt about reflectivity as much as its about specular reflection v.s. diffuse reflection. cost and ease of installment are also key points in the common argument making a clear "better" option, well, not so clear

james


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## tachikoma (Apr 16, 2009)

Ahh that makes sense, thanks for the clarification.


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## rbrock (Nov 2, 2008)

You're probably better off going with some kind of paint. I have tried the tape and mylar they usually don't stick very long with the heat.


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## Venutus1 (Feb 13, 2010)

rbrock said:


> You're probably better off going with some kind of paint. I have tried the tape and mylar they usually don't stick very long with the heat.


paint.. metal duct tape... reflective polyester mylar... good 'ol tin foil...

Ahhh... I have tried them all over 25+ years. First started using it in custom Reef tank lights.

That's why I sell the kind of tape that works best. 

I know for a fact it will stay stuck for 8+ years. 

Its the thinner kind than your run of the mill typical HVAC tape. 
Without the gawd awful thick "duct tape" glue-ey adhesive...and under 6 bucks.

The reason I prefer reflective tape (non mylar) over white paint is that it holds up better under UV exposure. 
Not all paints stick well to ABS plastic.... especially plastic that is constantly being heated and cooled as in a plastic cfl hood. 

Also, when it comes down to it, reflective metal is best reflecting material to use when UV lighting is incorporated. 
(All my set-ups are now set up with some level, modest or otherwise, of UV light. )

Cheers,
Todd
LightYourReptiles.com


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## Neontra (Aug 16, 2011)

Have you ever seen those reflectors in the lamps at the hard ware store? They have a smooth coat of paint that looks like tin foil. I don't know where you could get that paint, but I think it would work much better than white paint.


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## Venutus1 (Feb 13, 2010)

Neontra said:


> Have you ever seen those reflectors in the lamps at the hard ware store? They have a smooth coat of paint that looks like tin foil. I don't know where you could get that paint, but I think it would work much better than white paint.


hmmm... no. .
but sounds interesting!
I will scope around and see if I can see what you are talking about.


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## Neontra (Aug 16, 2011)

Venutus1 said:


> hmmm... no. .
> but sounds interesting!
> I will scope around and see if I can see what you are talking about.


Actually looking at it, they look like they're all metal w/o paint. But i've seen silver spray paint that probably is better too.


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## ryan10517 (Oct 23, 2010)

Neontra said:


> Actually looking at it, they look like they're all metal w/o paint. But i've seen silver spray paint that probably is better too.


are you talking about the 27 watt fluorescent daylight desk lamps? if so, the metal reflector on the inside is so close to the bulb that it actually does nothing for reflectivity. Seeing that it is only about 3/8" away from the top of the bulb, the light really doesn't have a chance to escape and get reflected. it just gets sent right back down on the bulb causing restrike and heat. I had two of those fixtures and i gutted them both and wired them up into a single fixture for my 20 gallon auratus tank. I have to have an 80mm computer fan running full blast to keep the bulbs from frying my frogs.


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## Neontra (Aug 16, 2011)

ryan10517 said:


> are you talking about the 27 watt fluorescent daylight desk lamps? if so, the metal reflector on the inside is so close to the bulb that it actually does nothing for reflectivity. Seeing that it is only about 3/8" away from the top of the bulb, the light really doesn't have a chance to escape and get reflected. it just gets sent right back down on the bulb causing restrike and heat. I had two of those fixtures and i gutted them both and wired them up into a single fixture for my 20 gallon auratus tank. I have to have an 80mm computer fan running full blast to keep the bulbs from frying my frogs.


150-Watt Incandescent Clamp Light-CE-300PDQ at The Home Depot


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## ryan10517 (Oct 23, 2010)

those are just aluminum. they work alright for what they are. glossy chrome paint on the other hand doesn't have that great of reflective properties.


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## dpal666 (Jul 8, 2009)

maybe just me, but why go with flat white paint instead of a full gloss?


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## james67 (Jun 28, 2008)

its all about the science of light. 

light hitting a truly mirrored surface, is simply reflected in a single identical angle leaving as upon entering the object.

when light hits a rough surface (like paint) it creates a diffuse reflection. meaning that the light waves bounce off the object in a number of different angles. white paint is suited best for this application, because as it happens, the colors we see are simply the effect of the light hitting the object and reflecting or absorbing some visible light waves. so a blue object absorbs the non blue light waves and reflects the blue, a black object absorbs all the light waves (why black objects get hotter in the sun) and white objects (like the paint in this instance) reflect all visible light waves.

SO, its simply a matter of whether you prefer to precisely angle your light with specular reflection (like a mirror or mylar) or whether you prefer a diffuse reflection, which scatters the light evenly.

james

gloss paint is a bad idea since it creates specular reflections in a very uncontrolled manor resulting in uneven lighting.


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## dpal666 (Jul 8, 2009)

that makes sense, thank you


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## ryan10517 (Oct 23, 2010)

james67 said:


> its all about the science of light.
> 
> light hitting a truly mirrored surface, is simply reflected in a single identical angle leaving as upon entering the object.
> 
> ...


This makes me remember high school physics way more than i want to hahaha


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