Cleaning smoke residue from old plastic

option.

I use oven cleaner aerosol , not preheating of course, as the instructions say. Check for compatibility first on a back surface ,especially for fastness printing/plating/clear plastic inserts etc. Its great for Al fascia and Al knobs as well. Wash down with water afterwards and wear gloves.

Take some time and do a search for THE method.

Never mind I did it for you.

Here is the nuts! (even though that seems wrong, in this context I think the grammar is correct)

It's pretty involved but it looks like it does a GREAT job. Mikek

It seems after reading the whole page, you need to go further to get the actual recipe. Mikek

I found this recipe in this thread.

There was a lot of research on this project. Follow up on the method it also uses UV light, some just us the sun.

We have been asked for a preferred recipe for Retr0bright, so here it is:-

1 pint (568ml) Hydrogen Peroxide, 10 to 12% Strength (this is bought over the counter at 12% strength or you can dilute the 35% grade) 1 Heaped Tablespoonful (approx. 45 grammes or 1/2 an ounce) of Xanthan Gum 1 Teaspoonful of Glycerine

Once this has been mixed together, to activate it, you add:-

1/4 teaspoonful (about 4 grammes) of an 'Oxy' based laundry booster, e.g. Oxiclean, Vanish, etc.

If it really was smoking, you should be able to remove the tobacco tar with just 90% rubbing alcohol or any household cleaner (409). However, I doubt that this is the cause.

If it's yellowed due to deterioration of the fire retardant plastic, you'll need to bleach it back to normal. As others have posted: I've done this several times with varying levels of success. The trick to prevent destruction is to dilute the food grade hydrogen peroxide from the stock 35% to no more than 15%. Even at 15%, there's a risk of bleaching the plastic white, instead of recovering its original beige color. Practice and the usual chemical safety precautions are advised.

Everyone has their own favorite mix and ingredients for Retr0brite. I don't have enough experience to be able to proclaim a winner, yet.

A drum machine as an antique? Well, ok.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

fascia

The oven cleaner I use has only had one bad reaction, to some chalk/mineral filled plastic that broke down the surface, dozens others have been no reaction, I just tried modern plastics marked PS (=polystyrene ?) and ABS . Unfortunately the smoke yellow surface comes up white (if white originaly) so loose that "patina" of age, much to the surprise of owners.

I would try first, just oxiclean and soap. Oxiclean makes it's own peroxide.

Greg

It won't work. You need UV exposure to get rid of the bromine. Also, I don't think the resultant H2O2 concentration will be sufficient. My guess(tm) is that it takes between 9% and 15% to get results. Too little and nothing happens. Too much and you bleach the plastic white.

You also can't do anything while the plastic is immersed under water. If you fail to use a thickener or gel agent, pulling the plastic out of the solution will just cause the solution to drip away. You might be able to get away with that by repeatedly rinsing the plastic in solution, while exposing it to UV, but that could easily turn into a PITA. The common compromise is to use cellophane wrap over the gelled mixture on the part, to keep it from dripping, while still passing UV. That works ok for flat parts, but doesn't quite work with complex shapes.

Also, if you start with the recommended 15% hydrogen peroxide concentration, and you dump in too much Oxiclean (sodium percarbonate), you could easily end up with too high a hydrogen peroxide concentration, which will bleach the plastic white. This happened to me before I learned to pay attention to the concentration. Incidentally, you cannot use a PH meter to guess the H2O2 concentration.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Thanks for the replies, might have to think about practicing on something else first though.

Gareth.

When I used to repair monitors, I used neat bleach & a stiff brush to clean cigarette yellowed cases.

Some people recommend odor absorbing kittie-litter to sanitise equipment that smells of smoking.

Yeah, that's worked for me, too. That or jif (or cif or bif or whatever they're calling it this week).

I've not tried the retrobright stuff before (it's been on the to-do list for a few years :-) on plastic that's suffered UV damage, but I believe that there can be problems with non-uniform restoration of the surface leading to a patchy/mottled effect, which personally I think I might find more irritating than a yellow-but-uniform colour.

cheers

Jules

Yep, a little lye (sodium hydroxide) in any cleaning solution works too. I've taken translucent-case iMac computers from smoke-gummy to like-new appearance with about a teaspoon of lye in a gallon of soapy water.

If it's yellow for ANOTHER reason, do a web-search for "Retr0Bright" .

We call that; "caustic soda", if you're not careful it attacks some plastics - but probably not so much in the concentration you suggest.

I used to use it in an ultrasonic cleaner to clean fouled spark-plugs - until I noticed it was taking the glaze off the insulators!!!