Home of Professional Cinematography since 1996
Published : 5th October 2003
Does anyone have a 'trade secret' they'd like to share on getting burnt moth stains out of the soft matt aluminium reflectors used in large soft lights? [Similar finish to the normal Redhead reflectors.]
I've used methylated spirit (I’m not sure what it's called in Nth. America - basically it is alcohol with an impurity added to stop you drinking it ) which removes about 50% of the brown mess. I can't sand or polish the aluminium as this would ruin the rough finish.
Clive Woodward wrote:
>I've used methylated spirit…which removes about 50% of the brown >mess. I can't sand or polish the aluminium as this would ruin the rough >finish.
You might try Naptha / Lighter Fluid. It's a great solvent and works well on metals without being too harsh. Just make sure it's dry before you fire up the light.
ICG, New York
Here's a suggestion from left field : oven cleaner.
Since it's designed to remove baked on organic compounds I would think it would do the job.
I would first test it on a small portion of the reflector to make sure it doesn't etch the metal.
Randy "moths are food to something" Miller, DP in LA
Clive Woodward writes :
>I've used methylated spirit (not sure what that's called in Nth America - >its basically alcohol with an impurity added to stop you drinking it
Over here it's called "denatured alcohol ".
Crispy critters on reflectors are essentially baked-on carbon -- really tough to remove. You could try very fine steel wool, used wet. As for solvents, maybe try acetone or the stronger methyl-ethyl-ketone (MEK). Use both with extreme caution -- they're highly volatile and flammable -- potentially explosive.
Over here in the states you can get solvents distilled from citrus peel -- they're essentially citrus turpentine. One popular brand is Citra-Solv. You can also get similar stuff in auto parts stores. This stuff isn't as volatile or toxic as the petroleum distillates, it can be diluted with water, detergents added and so forth, and it smells like oranges -- but is not drinkable! One thing it does better than just about any other solvent is take gooey or dried adhesive-tape stickum, label adhesives, etc., off cables and other surfaces. It cuts grease so well that, used undiluted, it'll take the oils right our of your skin, so after using it it's a good idea to lay on some hand lotion.
Marin County, CA
Dan Drasin writes :
>It cuts grease so well that, used undiluted, it'll take the oils right our of >your skin, so after using it it's a good idea to lay on some hand lotion.
I'll second this warning. Having used the orange based solvents, I was naive enough to consider that the stuff was so full of orangey goodness that it was bound to be skin friendly. Wrong! Even a small amount can cause intense dryness and eruption of skin conditions. So while the stuff is very good I would strongly recommend hand protection with either a barrier cream or suitable gloves.
Easy-Off Oven cleaner or Trisodium Phosphate. (TSP)
Don't leave either in contact with the aluminium too long and be ready to neutralize them with a mild acid like vinegar. Start with a dilute solution.
There are specific compounds for removing carbon from aluminium. I think one is called Carbon-X. It's used to remove jet exhaust from aircraft engine cowlings.
If you have a lot to do, crushed walnut shells in a sand blaster at low pressure will do the trick and won't abrade the reflector.,
Brian "The things you learn on industrial films." Heller