# Cleaning bar light diffusers



## AquaNeko (Jul 26, 2009)

I've got a 18" bar light that is all fjizzed up with yellow stain and am wondering what cleaning agent (prefer home remedy first before chems) I can use to revert that to the white color on the back or as close to it?

IIRC it was used over my fish tank when I was a kid by my folks to illuminate the tank. 

Later it was used for my indoor greenhouse germinating project.


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## kaegunim (Jan 15, 2010)

Is the lens plastic? If this is the case, then it is probably acrylic, and either heat or UV damaged, in which case it is a matter of repacement rather than cleaning. If there was something spilled on the lens, then I would suggest trying to soften it with water and getly-ish rub it off with a cloth. Avoid organic solvents if possible, as you would be surprised at how many things will eat into or discolour acrylic. If you do end up having to resort to a grease cutting cleaner, try to leave it on the acrylic for as short a time as possible to avoid clouding, and rub very gently.

If you are lucky enough to have a glass lens then you can get most of the film off with a razor, then finish with your choice of houshold cleaners.

If it is the reflector behind the tubes that has develloped a coating (as in from the deposition of aerosolised oils from cooking, air fresheners etc that have been baked on), then rubbing with some dry paper towel will do the trick. If it is more stubborn, then something with some organic solvent in it will help. I like the orange-oil cleaner myself, but have had sucess with a spot of WD-40 also~

If this is an older fixture with magnetic ballast (these tend to get fairly hot) it is also possible that the paint on the reflector has yellowed from heat damage - a strange design flaw for a lighting fixture, but unfortunately common. If this is the case, then rubbing will more than likely case the paint to crumble off. Adding a solvent to this sort of paint will likely soften it further and you will get large areas sloughing off. This situation is one where you aill either have to live with it or peel off the paint with a heat gun and repaint with some high heat gloss paint... which is alot of work.

And I realize that the topic says diffuser, so I got a little afield >_<


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## tebore (Jan 3, 2010)

If you have to replace it I'd recommend going with large piece of Lexan by GE those are the best piece of plastics acrylics. Heat resistant (ignites at 426C) and some of the best UV resistance I've seen in Acrylics. They sell them in pretty cheap large sheets you can cut to size. You can pretty much build a small tank outta this stuff. 

They come clear and opaque, I'm sure you'd want to use opaque as a diffuser. 

To give you a taste of the heat resistance you'd need a butane torch to soften it to shape or an industrial heatgun(the $20 one at crappytire won't get the air hot enough). I used to shape generic acrylics by boiling them but this won't budge until high heat is applied.


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## AquaNeko (Jul 26, 2009)

tebore said:


> If you have to replace it I'd recommend going with large piece of Lexan by GE those are the best piece of plastics acrylics. Heat resistant (ignites at 426C) and some of the best UV resistance I've seen in Acrylics. They sell them in pretty cheap large sheets you can cut to size. You can pretty much build a small tank outta this stuff.
> 
> They come clear and opaque, I'm sure you'd want to use opaque as a diffuser.
> 
> To give you a taste of the heat resistance you'd need a butane torch to soften it to shape or an industrial heatgun(the $20 one at crappytire won't get the air hot enough). I used to shape generic acrylics by boiling them but this won't budge until high heat is applied.


Oh man... I <3 you. You're so hardcore, I love it.   Friendly love that is. 

Not sure about the moulding thing as IIRC (from Home D) you have to buy a large sheet of the stuff andI only need something liek 18inches. Even with the excess it's a bit of an excess to have around.


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## AquaNeko (Jul 26, 2009)

kaegunim said:


> Is the lens plastic? If this is the case, then it is probably acrylic, and either heat or UV damaged, in which case it is a matter of repacement rather than cleaning. If there was something spilled on the lens, then I would suggest trying to soften it with water and getly-ish rub it off with a cloth. Avoid organic solvents if possible, as you would be surprised at how many things will eat into or discolour acrylic. If you do end up having to resort to a grease cutting cleaner, try to leave it on the acrylic for as short a time as possible to avoid clouding, and rub very gently.
> 
> If you are lucky enough to have a glass lens then you can get most of the film off with a razor, then finish with your choice of houshold cleaners.
> 
> ...


It's a plastic 1/4 U shaped curve on it. Gah.. I don't know what it is material wise other then plastic. You're likely right that it is acylic. It's about I think probably 20-25yrs old that I got from my folks. Metal housing, push and hold to turn on button (flickers then on), and a diffused plastic soft white frosting . If that helps any. Anything else I'm not sure. I know my dad's got a heatgun (not Can.T) but I think by Master and 2 settings. First setting is feels like 3-4 times hotter then a 1850W hair dryer the second one like you can't count to 2 if you held your hand over a red hot charcoal grill at prime heat setting for good searing. That's the best reference I can give. I'll the water and scrub thing. Might try vinegar but wanted to check first.

The 18" bar light may be old but it's still working so why chuck or cannabilize it for parts while it's still working. The other Home D 18" bar lights I've got (~3 total from Home D) are all plastic and in recent years purchase so yah I'm sure I can get replacements but those have not shown any decolourating (sp?) and housings are all plastic. All my 18" bars are factory 2 prong plug ins and not custom prong wired.


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## tebore (Jan 3, 2010)

AquaNeko said:


> Oh man... I <3 you. You're so hardcore, I love it.   Friendly love that is.
> 
> Not sure about the moulding thing as IIRC (from Home D) you have to buy a large sheet of the stuff andI only need something liek 18inches. Even with the excess it's a bit of an excess to have around.


You can never have too much Lexan on hand? 

I've made a whole hood(I guess you can call it that) for my 3gallon tank with this stuff and I'm hanging 2 SSC P7s running at just over 1.5 watts. 
I'd say just ~250lms (50mA per die with 8 dies each one around 25lms. IIRC the sheets correctly). Fully dimmable. I want to boost the lighting up but I can't seem to find the right wallwort. The one I got now is 6V 300mA. I need something closer to 7V 1000mA ideally to get around 500-600lms for proper plant growing light. I'm thinking maybe modding an Apple USB power supply 5V-1000mA and adding an inline resistor to bring the voltage down and mA to a max of 700mA.

Lexan is fun stuff you can use it for anything if you drill holes you can make a divider. A heat gun, dremel and a lot of Lexan on a boring saturday afternoon it's more fun then a barrel full of monkeys. Works great for bike stuff too.

Sorry for the 'off-topicness". I get a bit excited when I mix GTAA and CPF.


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## AquaNeko (Jul 26, 2009)

tebore said:


> You can never have too much Lexan on hand?
> 
> I've made a whole hood(I guess you can call it that) for my 3gallon tank with this stuff and I'm hanging 2 SSC P7s running at just over 1.5 watts.
> I'd say just ~250lms (50mA per die with 8 dies each one around 25lms. IIRC the sheets correctly). Fully dimmable. I want to boost the lighting up but I can't seem to find the right wallwort. The one I got now is 6V 300mA. I need something closer to 7V 1000mA ideally to get around 500-600lms for proper plant growing light. I'm thinking maybe modding an Apple USB power supply 5V-1000mA and adding an inline resistor to bring the voltage down and mA to a max of 700mA.
> ...


You're not alone there.


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