Re: Air filters for big 500 series scopes


In my experience for removing grease and oil from stuff (foam filters,
aluminum filters, clothes, etc) I use Dawn detergent. It does not contain
phosphates. It is biodegradable and is fairly gentle on the skin. Some
other discussion groups - specifically one on aircraft and cleaning of
them, warn against any cleaners containing chlorinated detergents for
cleaning aluminum. The makers of Dawn list all their ingredients:

It does contain sodium hydroxide. By itself, sodium (or other alkali metal)
hydroxides will attack aluminum. Dawn uses it as an adjuster for pH not as
a primary cleaning agent. It does contain sodium chloride and is used as a
thickener. I have not had a problem using it on aluminum, but if the
aircraft folks recommend not using it, I would not for structural parts. I
do rinse the parts off very thoroughly.

On Mon, Oct 19, 2020 at 22:39 Roy Thistle <>

On Sun, Oct 18, 2020 at 11:56 PM, snapdiode wrote:

Scrubbing Bubbles
It doesn't use phosphates (which are not good for the environment)... but
might not clean these old scope filters as well as a phosphate cleaner.
Instead of phosphates, Scrub Bub uses a surfactant, combined with a water
softener. Scrub Bub seems safer, for the aluminum filter, and for the user

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