Cleaning plastic instrument covers

[FloatingMoneyPit]

The plastic white cover for my Standard Horizon multi meter has turned grey and spotty over the last 2 years. None of the standard cleaners I have on board seem to do anything. I could just wet sand the thing, but then the logo would come off and I couldn't do their advertising for them. Hmm, maybe I could paint a little design of my own on it.
Ditto for the PVC cowl vents. The mildew comes off, but there's still some black stuff. I know, I should step up and get bronze or s.s., but until then, I'd like to keep the ones I have clean.
Anyone have any tricks or miracle products to clean these things without ruining them?

[Rachel]

I've used a "GoJo" type orange cleaner on fenders. Not the spray stuff, but the the one that's more like a lotion or cream. I assume it has some pumice in with the orange. Worked well, and much less obnoxious than the acetone that was quickly becoming my last option.

I've heard of WD40 being used but haven't tried it myself.

And "409" sometimes works on white plastic, although perhaps you're past that stage :-)

--- Rachel

[Summersdawn]

I can't remember exactly which one I used, but it was a common household brand name cleaner. It was a bleach gel (no grit in it). It turned my yellowed plastic gleaming white again. You might want to check the cleaning isle of your local grocery store for a bleach gel.

[Tim]

I have the same Horizon covers, and the same staining problem. Admittedly, I haven't tried too hard to clean them, but I haven't found a successful product yet either.

If you find something that works, please post!

[Jedediah]

We use Citrol and Penetrol at work for most of our cleaning which admitably does a pretty good job, although we're dealing with back deck equipment usually. Any scouring agent will help the first time or two but make it harder and harder as you'll be adding more small grooves for things to take up residence in. Citrol and scotchbrite will clean most things but be warned it won't leave a shinny surface, although you can try the MicroMesh below and return a little of it on some plastics or go with a full buffing setup.

If you are going to wet sand the dial surface I'd recommend MicroMesh sand paper. I've had good luck returning plastic surfaces to their original, although not as good of luck using it on copper mirrors for lasers or glass. The stuff was designed for sanding plastic and works well for that. You might look into the CD 'refresher' products which some add a small amount of plastic to fill the gouges. If its glass, you could try the same with auto window repair kits which have a very thin UV cure epoxy which might just give you enough surface fill so that when you sand down it won't remove your logo.