diy reflector ???

[jetchris]

ok i did a search on diy reflectors for MH's. I found from that search is that it is better to paint the inside of your hood gloss white than to make a diy reflector. What I was planning on was to use that aluminum reflective tape over some old faded reflectors that i got used. What is your opinion on this situation and do you have any good ideas about diy reflectors ?? Please dont say i am better off spending $60 on new reflectors. Looking for DIY stuff.

Thanks,
Chris

 

[jetchris]

leveldrummer you must keep busy on here lol

 

[wbholwell]

IMHO, that's rubish about the white paint. Polished aluminum would do a better job. If I were making a DIY reflector, I'd borrow one that wasn't too complicated and copy it to the best of my ability. Good luck, and let us know how it goes.

 

[skriz]

I made one from roof flashing. I buffed and polished it to make it even more "shiny". Then, I copied the style of the spider reflector and bent it to shape. Worked brilliantly..way better than white paint.

white paint is not better than reflective aluminum. that's kak!

 

[glxtrix]

I was thinking about sayin that too mainly cuz capp bay utilizes mirrors on some tanks, but they are angled and not directly shining at the water. Would a full mirror light hood generate too much light tho, like enough to burn the corals? Hmmmm.

 

[skriz]

it definatley wont burn the corals; remember, people use 1000 watt halides without problems.

I think the problem with using the mirrors was they would corrode easily. The reflective part of the mirror is the stuff attached to the back of the glass and I think it is weak. Can't really remember though. would have to do a search on rc.

 

[cameron]

Try mylar or even foil. Keep in mind that the design of the reflector has an impact on PAR as well.

 

[piznac]

I have some polished stainless steel,.. and access to a metal break. I was thinking of doing this myself. I would think that is all you need.

 

[cameron]

I have seen at least one install that did it in mylar which would be much easier and less dangerous than mirrors.

 

[jetchris]

thanks for the ideas , i found some diamond plate "free" so i am gonna cut and bend it to the shape of a regular reflector. Ill cean it up a bit and it should do a real good job. Thanks again

 

[skriz]

ooh, I bet diamond plate will give some cool reflective properties. Post pics when your done.

 

[kh971]

It probably will not bend easily, it might break into, so don't be alarmed. There are more than a 1000 different types of aluminum. Some with different compositons than others for hardness.Plate is usually made harder.

 

[justonemoretank]

You are going to loose some of the light output if you go with the mirrors. The light is filtered and some is lost when traveling thru glass. Using a mirror the light travels thru the glass, hits the reflective material, and then has to travel thru the glass again before reaching the water. Too much is lost in my opinion.
Some well polished roof flashing or bent aluminum would be much better.
I had a schematic for a DIY Reflector that looks just like a LUMINARC

 

[siege]

I am with Cameron, I would suggest Mylar or foil, just be very careful with heat output in something like a hood, esp. with mylar, as there is a very good reason it's used for emergency hypothermia blankets. Additionally, instead of mirrors, what you might consider bits of glass silvered on the outside, as is done on some automobiles (where legal). As mentioned by others above, unless you use really high-quality optical glass designed for just such a spectrum-transmission, any kind of silvering on the backside of the glass won't work, but any silvering on the side closest to the lamp itself ought to work nicely. I don't think the stuff necessary to do the silvering yourself would be cheap enough, but you could probably get a glass shop to make the panels for you with the reflective coating on the proper side, assuming it wouldn't corrode.

Really, Mylar is liable to be your cheapest and most effective solution, I think (assuming you're like me and too lazy to polish aluminum flashing).

 

[james s_]

You can get the spectral aluminum at Aquaticco.com I believe it is $7 a sq. ft.
Got the best reflective properties of anything ive seen.

 

[mufret]

I remember reading an article a number of years ago that stated white paint was actually a much better reflector of light than a mirror when used to light aquariums or grow plants because of the issue that JustOneMoreTank mentioned about. Hamilton also uses white paint in many of it's fixtures so there must be something to it.

 

[siege]

46bfinga: Great find, thanks for that!

mufret: I can see that... White IS highly reflective, hence its use in clothing and building materials in high-heat environments. However, while it might be better in this applitcation than a mirror, this is probably related to the wavelengths that the glass itself will absorb and scatter. A properly mirrored surface without glass to travel through is still probably best... I'd be interested to see more research in this regard... I'll have to look up more on it when I get home from work.

 

[enderg60]

wow ok lots of bad info here.

Mirrors are bad, you will loose light as it must go through the glass twice to get reflected, and the reflective surface on the back will peal off or corrode very easy.

Mylar and similar materials are usless as well as they will burn off, if you get it anywhere near a halide.

White paint inside the hood helps, but it is by no means anywhere near as good as any reflector. The white will help keep the heat in the surrounding air so it can be removed by fans instead of being absorbed into the wood.

Polishing your Al will work, but you wont get it anywhere near as nice as a good spectral sheet of Al(95-98% reflectivity as opposed to maybe 80-85% with standard polishing)

Most cheaper reflectors use hammered or diamond plate material to diffuse the light to avoid hot spots produced by the halides, these are simple not very effective designs when you want maximum light transfer.

Now then get yourself some nice spectal Al, and make yourself a break(metal bending tool) you can do it simply with a set of 2x4's and some clamps. Cut the metal with a cut off wheel(dremel will work) not shears as they deform the metal. For simply good designs the spider or parabolic reflectors work very well(i would recommend cutting some flat end peices for full enclosure)

If you can get your hands on a better break so you can bend 1/4" tabs then its not that hard to make a good luminarc style reflector. I cant seem to attache the templet for the lumin arc but pm me and ill send it to ya.

Unless your planning on using good quality Al, dont bother trying to make one it just wont be worth it, your better off spending the $30 for a spider reflector.

 

[justonemoretank]

Ender is right.

I did find a skematic posted a while back on RC. This shows some dimensions for a L u m e n a r c style reflector. You can modify the lengths as you need to make whatever size you are looking for.
Using the Spectral Aluminum you should get a nice piece. I have seen pictures of really well made units on RC.

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[siege]

Thanks for the good info Ender and JOMT.