addicted_2_reef
New member
Just wondering if anyone has made a refector for MH lights out sheets of aluminum from HD? The have some thin dimond plate that is polished I was also considering using that.
-Brian
-Brian
DIY Reflector
- Thread starter addicted_2_reef
- Start date
NJReefGeek
New member
HD stuff is not reflective enough. If you want to DIY one use regular aluminum and paint it bright white.
You can also find some used ones farly cheap around here or on ebay.
Next week I will have 2 used ones for sale.
Andy
You can also find some used ones farly cheap around here or on ebay.
Next week I will have 2 used ones for sale.
Andy
Tigger240
New member
id think any type of metal would be more reflective than white paint.. and anyway you can polish the crap out of metal to increase its reflectivity. ive seen on another forum where a guy made a luminarc type reflector out of metal and pop riveted it together, it came out sweet. sorry, i dont have a link tho
bristlebasher
New member
Matt white is reflectively speaking a good material but discolours too quickly due to heat - and has to be "Pure" white or else the spectrum will be altered - stick with metal.
I was waiting to bring this up till I had it done.
At most good hardware stores they sell aluminum flashing. About a foot wide, multiple lengths but usually around 10' per roll (I got one for around $8). Take some of this, lay it out flat. Then get some 400, 600, and 1000 grit wet/dry sandpaper. Keep the surface wet, and sand the sheet. I find it best to always go in one direction with each type of sandpaper. So lengthwise with the 400, then width-wise for the 600. This will make it easier to determine when you have removed the scratches from the previous paper. Then get yourself a buffing wheel (they make ones that fit on a dremel that will work well or for a drill) and some buffing compound. Harbor freight sells everything you would need for cheap. Be careful when buffing as the metal will get hot and too much heat could cause warping. You can always put water on it to cool it down, but make sure its dry before you try to buff again.
Now for MH you can probably skip this part and just hand form the rest, but if you do this for any flourescents it will be helpful. Roll the aluminum around a piece of PVC to get something close to a parabolic reflector. You don't need to mimic the curve of the PVC exactly (think back to algebra class and the graph of a parabola, try and mimic that shape using the pipe as an aid)
As I said, I have not done this for a reflector yet; I am hoping to have time next week, however I have polished the intake on my truck this way. Just remember to take your time and don't expect it to be the holy grail of relfectors.
Also, avoid the diamond plate. That stuff is expensive and hard to work with if you don't have the right tools.
At most good hardware stores they sell aluminum flashing. About a foot wide, multiple lengths but usually around 10' per roll (I got one for around $8). Take some of this, lay it out flat. Then get some 400, 600, and 1000 grit wet/dry sandpaper. Keep the surface wet, and sand the sheet. I find it best to always go in one direction with each type of sandpaper. So lengthwise with the 400, then width-wise for the 600. This will make it easier to determine when you have removed the scratches from the previous paper. Then get yourself a buffing wheel (they make ones that fit on a dremel that will work well or for a drill) and some buffing compound. Harbor freight sells everything you would need for cheap. Be careful when buffing as the metal will get hot and too much heat could cause warping. You can always put water on it to cool it down, but make sure its dry before you try to buff again.
Now for MH you can probably skip this part and just hand form the rest, but if you do this for any flourescents it will be helpful. Roll the aluminum around a piece of PVC to get something close to a parabolic reflector. You don't need to mimic the curve of the PVC exactly (think back to algebra class and the graph of a parabola, try and mimic that shape using the pipe as an aid)
As I said, I have not done this for a reflector yet; I am hoping to have time next week, however I have polished the intake on my truck this way. Just remember to take your time and don't expect it to be the holy grail of relfectors.
Also, avoid the diamond plate. That stuff is expensive and hard to work with if you don't have the right tools.
BeanAnimal
Premium Member
Guys not to burst anybodies bubbles here...
There is a LOT more too a good reflector than the material it is made out of. The shape is the most important part of the design. Modern MH reflectors are designed using software. The shape is engineered to provide the best focus of light with the least amount of reflections from the bulb to the water. The distance from the bulb to the reflector, the diameter of the bulb, the over footprint of the reflector and many other factors come into play.
What does this all mean? That your DIY reflector will likely only get about 60% of the light to the corals as compared to an engineered design.
With regard to DIY SLR reflectors for T5s.... your really wasting your time! You will come nowhere near what the current offerings provide in terms of efficiency.
With regadard to polishing your own flashing... that is a lot of work when you can buy already polished specular aluminum that far exceeds the reflectivity that you will be able to acheive with a DIY polishing process.
Guba.. they sell specular aluminum that
There is a LOT more too a good reflector than the material it is made out of. The shape is the most important part of the design. Modern MH reflectors are designed using software. The shape is engineered to provide the best focus of light with the least amount of reflections from the bulb to the water. The distance from the bulb to the reflector, the diameter of the bulb, the over footprint of the reflector and many other factors come into play.
What does this all mean? That your DIY reflector will likely only get about 60% of the light to the corals as compared to an engineered design.
With regard to DIY SLR reflectors for T5s.... your really wasting your time! You will come nowhere near what the current offerings provide in terms of efficiency.
With regadard to polishing your own flashing... that is a lot of work when you can buy already polished specular aluminum that far exceeds the reflectivity that you will be able to acheive with a DIY polishing process.
Guba.. they sell specular aluminum that
One point then I will leave this be.
This is the DIY section, not everything built from instructions here will function as well as a CAD built piece made on a CNC machine at a high price factory. I think most everybody is aware of that. Some of the people here do this for fun, other do it because we have more time than money. (for my DIY reflectors, I'm spending about 20 bucks, instead of 100)
If we want to revel in our mediocre creations, let us. As long as we aren't abusing the fish/ corals/ people from pittsburg
, just keep your bubble bursting to yourself.
Sorry to be off-topic
This is the DIY section, not everything built from instructions here will function as well as a CAD built piece made on a CNC machine at a high price factory. I think most everybody is aware of that. Some of the people here do this for fun, other do it because we have more time than money. (for my DIY reflectors, I'm spending about 20 bucks, instead of 100)
If we want to revel in our mediocre creations, let us. As long as we aren't abusing the fish/ corals/ people from pittsburg
, just keep your bubble bursting to yourself.Sorry to be off-topic
hllywd
Premier World Traveler
You can polish the aluminum till you are blue in the face and it's not going to work like specular aluminum. Specular has a mylar coating which makes for about a 98% reflective surface. You'll never get that level of reflectivity by polishing and then it will corrode and get worse. Just not a great idea... If I remember what I've read correctly, the flat white painted reflector does in fact out perform polished aluminum.
Tim
Tim
BeanAnimal
Premium Member
guba just making it clear that the average DIYer is not going to build a reflector that meets or exceeds something that can be bought for a reasonable price.
Most of the time we are trying build something that meets or exceeds the overpriced real deal
Most of the time we are trying build something that meets or exceeds the overpriced real deal
BeanAnimal
Premium Member
?
Not to put you on the spot, but do you have anything to back this up?
I only ask because I understand what your saying. The reason most aircraft are painted white is it makes them brighter and more distinguishable at a distance.
I would gladly paint the sheet of aluminum I have white and just form it than polish and protect it.
Also, since I've read heat can be problem for use with MH bulbs (since that is the point of this thread), does anybody think an automotive finish would do well? I see painted engines all the time and they hold up to 500+ degrees.
