reflectors

[tcyiu]

I am refurbishing an aluminium hood. It appears to be anodized aluminium which means that it is a dark bronze almost brown colour.

So the upshot is, I need a reflector above the fluorescent tubes.

I bought some galvanized steel flashing made for rain gutters. The cross section is like the letter L. I cut them to length and got them to fit nicely behind and above the flourescent fixtures. But now that everything is re-assembled, turns out the front panel cannot swing up because the flashing is 1/4" too wide.

Despite having invested a bunch of time, I am re-thinking using the sheet metal. Although the sheet metal is light grey, it is not that reflective. Plus being a different metal, it may hasten galvanic corrosion with the aluminium.

So I am now open to other ideas for reflectors. It seems the main criteria are:
1. will reflect much of the light back down towards the water
2. won't be affected by the heat from the lamps
3. won't corrode or cause corrosion in the hood
4. is reasonably light (i.e. I would not want to put glass mirrors in the hood)

In the past, I've had good success with aluminium foil. But it is really cheesy and looks too home-brew.

Thanks,
Tim

[Genirous]

Hi Tim,
unfortunately no matter how good your DIY reflector may be, the time and effort spend don't worth it, because there are many available reflectors from aquatic (and not only) companies that offer good products on good prices...

Inspite the above, if you want to try your skills there is a good article here! I believe that the guy may exaggerate a little bit, but there is good info inside!

Friendly,
Giorgos

[tcyiu]

Thanks Giorgos. I read the link with interest. I am wondering who else might sell reflectors. The guys at AH seem to sell complete kits. I am trying to get away with as cheap as possible.

The bill as of right now is:
- Heavy gauge anodized aluminium hood - FREE
- 4 x "Lights of America" 2ft lamps* from Walmart ($12 ea)
- 10ft flashing (~$6)
- Misc bolts/nuts ($4)
- Outdoor extension cord (refurbished one that was lying around) FREE

*the lamps are fully integrated with instant fully electronic ballasts inside a reasonably compact fixture.

So I am only out about $60. Since I'm not planning on a planted aquarium, I think this solution will do. But I am looking to extract as much light as possible from these cheapie fixtures.

Perhaps white exterior paint might be the answer??

Tim

[Genirous]

Some aquarium companies like Arcadia, Juwel, JBL etc have fluorescent lamp reflectors and you may find some to buy in ebay...

Except from them, you can find such reflectors from companies manufacturing lighting fixtures or maybe lamps like GE or others! The more you search the best choice you can take! Unfortunately I don't know the American market to assist you...

The white paint is a good solution, but not the best if you want to have the best result possible! The reflectors must have a mirror-like surface and also placed at least 2cm away from the lamp!

[tcyiu]

Found the solution ... I think.

I went to a LFS which is known for good prices. Each 2' reflector would have cost around $15. Too much for me. So I kept looking for another solution that does not involve painting the inside of the hood.

At a local hardware store, I found this stuff called Foil Tape. It is used to seal duct insulation which is a shiny bubble wrap like material by a company called Reflectix. This tape is very similar to duct tape, but it is very reflective. Because it was intended for HVAC applications, I was told it is rated to go as high as 180 deg F.

It cost $4.10 (with tax) for a 30'x2" roll. Even if the adhesive peels off, I will be able to apply it 3 more times before I need to get a new roll.

I think I win the prize for being cheap. :-)

Tim

[RockHound]

Not sure if it applies to your application.
Mylar
http://en.wikipedia.org/wiki/PET_fil...ially_oriented)
And, a can of weather-proof spray adhesive.
I used this to make large flat surface areas about 99% reflective.
In a greenhouse, I culture/propagate/grow orchids in.

Spray can adhesive can be found @ about any home improvement store.
Mylar in rolls can be found @ hobby/craft stores & eBay.
Neither are expensive.

[tcyiu]

Mylar

Hmmm VERY interesting. I did not think of it, but it is used in applications where there is strong direct sunlight. So it should be quite stable next to a flourescent lamp. Plus according to the wiki, it is 99.9% reflective when metallized.

Tim

[tcyiu]

I've now had a chance to use the Reflectix foil tape. This is really good stuff for my application which is to give my DIY hood some reflectivity behind the flourescent tubes.

The tape is made of metallic foil (not shiny plastic). The reflectivity appears to be good - perhaps not as good as Mylar which is rated at 99.9%. The adhesive appears to be similar to duct tape (I guess because it is used for the same sort of thing).

All in all, it was easy to apply and not at all messy. The foil comes with a backing strip. So you can position the tape first and slowly peel away the backing strip to expose the adhesive.

I do not know what the long term use is going to be like. Hopefully, I'll remember to come back and report on how it does in a moist environment.

Tim