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Cleaning smoked plastic

A

alexkerhead

Veteran Member
Joined
Mar 13, 2006
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Location
Montgomery, AL USA
Does anyone know of a good tutorial for cleaning smoke stained plastic.
I have tried lighter fluid, bleach, 409(and copies), etc.
I have some nice old wang terminals that are just filthy nasty from the previous owner smoking up a storm around them.

note-another good reason not to smoke.
 
Any good, strong solvent should remove cigarette smoke, but what you're dealing with may not be smoke at all. Some types of plastics tend to discolor (yellow) with age Sunlight seems to accelerate this process. AFAIK, no one has yet come up with a solution to reverse this problem, other than spray paint.

--T
 
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As Terry said, the white plastic tends to yellow with age, and there isn't anything that can reverse that.

However, for plain old grime, I've found that Soft-Scrub works wonders. Use a damp cloth and rub it in good, like you were waxing a car. A final wipe with a clean, damp cloth should remove the Soft-Scrub and crud. The bleach also has a whitening effect, but I don't know if there will be any long-term damage to the plastic. I've used it for the past several years and haven't noticed any deterioration yet.

Kent
 
Terry Yager wrote:

> Any good, strong solvent should remove cigarette
> smoke, but what you're dealing with may not be smoke
> at all. Some types of plastics tend to discolor
> (yellow) with age Sunlight seems to accelerate this
> process. AFAIK, no one has yet come up with a
> solution to reverse this problem, other than spray
> paint.

Wonder if Solarguard Paint would be any good? It's been
designed to be a hardy paint for the Australian roof - so it
tollerates the Sun & Rain (not that we seem to be getting much
of the other). The fumes maybe an issue though.
 
Thanks a bunch for the advice.
You maybe right, it could be age yellow, the only thing I have ever had success with it actually scratching a thin layer of the plastic off, but it is tedious and difficult.
I wonder if a thin wire steel wool would work, I will try on the back of the monitor tommorrow.
 
I'm sure you've thought of this already, but it would be a good idea to remove the back of the monitor before using steel wool on it. Bits of steel wool falling into the monitor could prove...um...exciting to say the least.

Kent
 
some of my Tandy 2000's are kinda yellow. I soaked some (the cases butthead) in say a 50/50 bleach-water solution. Had some effect, but didn't do the job entirely. Bleach will do it, but if too strong it might wind up eating the plastic. Careful
 
I tried it on a old bad monitor, the steel wool idea with bleach, it had promising results, but a finer steel wool will be needed, because you could see the scratching on the briary stuff I had.
I will get some tiny thread steel wool tommorrow and post results, hopefully we have developed a really good solution for yellowed and smoked plastic.
 
I've experimented with very fine sandpaper, in like, the 6 - 800 grit range, with similar results. It works, but you can still see the scratch marks, which I found unacceptable. (Plus, it takes forever). You might also try a strong Hydrogen Peroxide solution (the good stuff, intended for whitening teeth, not the weak-ass stuff they sell for cleansing wounds). A 70% solution might have some effect, but would be rather expensive.

--T
 
I collect old radios and test eqpt, and "409" has never failed to easily remove the discoloring caused by cigarette smoke, so I doubt that's your problem.

If it's really surface yellowing from age/sunlight, an abrasive will probably be the only possible remedy. I think that even very fine steel wool might be too agressive and leave visible scratches, and there's that problem with the little steel whiskers.

Some finer abrasives/polishes that work well for me on both plastics and metal are, in order of decreasing agressiveness and grit size, kitchen sink cleanser (e.g., "Comet"), Flitz (a paste that comes in a toothpaste tube), Brasso (yes, the metal polish), and Classic Car paste wax/polish. I would try any of these before resorting to steel wool or sandpaper.
 
like Terry said, some fluids will work, but you have to submerge the parts of the unit that need whitening (de-yellowing?). Or at least say the left side of the case first...(each part one at a time). And yes it can be kind of expensive. Like I said, a strong (stronger then the 50-50 I used) will work, but you need to be careful. It took a couple of days. Abrasives will work too, but you mar the surfaces you're dealing with. Micro-mart (I believe that's their name) used to sell a super fine grade of material for sandblasting with a small airbrush (used for spraying models and such). Probably can find it other places too. Never tried it, but that possibly could be a solution. Again, you'll mar the surface this way also, but you stand a chance of producing the grainy surface that's at least similar to the original. Just a suggestion.
The best thing to try in the case of a computer case is to find some sort of wide/long reasonably deep tray, place the item in it, then try a strong bleach/water solution (25/75?). This way you'll use as little of the fluid as possible. Or, possibly wrap the part in old rags (colored ones may run on it!) soaked in bleach, then put it in a thick plastic bag and tie it. You could also wrap the thing, then pour on the bleach (don't start off with it strait though).
I just got 2 skanky Victor 9000s delivered today, and I need in a big way to whiten these bad boys. I'll get back with some results (maybe some pictures too). But it may not be immediately.
Maybe there's some sort of enzyme on the market that can more easily deal with this stuph. What about that CLR (Calcium-lyme-rust) removal stuph? Someone said it was real strong and might eat the plastic? Don't know...
I wasn't calling anyone a butt-head by the way. Just the person that was wondering if I submerged the whole computer in bleach! lol
 
"The best thing to try in the case of a computer case is to find some sort of wide/long reasonably deep tray, place the item in it, then try a strong bleach/water solution (25/75?)."

Probably should have put 75/25 (% of bleach to water)
 
A method I've used for very large, bulky, or odd-shaped items is to wet a paper towel with the required solution and lay it on the surface. Perhaps you could then put plastic wrap over it to keep it from drying too quickly.

Kent
 
"Chris,

Keep in mind that those Victor 9Ks never were pure sno-white, even from the factory. They're s'pozed to be somewhat off-white.

--T"

I was going to ask you that very thing Terry lol. But what I tried today was the Clorox gel stuph (says formerly Advantage on the bottle). WORKS VERY WELL. In a matter of minutes it whitened small areas of a case. Yes I imagine the bleach could actually remove some of the natural color, but what can you do. Some of these things are just so skanky. Even with the gel stuph, it would take repeated applications. I only experimented some, plan to get some sort of tray to lay something in a pool of it (albeit shallow). I wish there was a way to buy sheets of that soft aluminum they use to make those turkey pans. This way you can tailor the tray for the part, so as not to use more bleach then you have to. Any clues?

"A method I've used for very large, bulky, or odd-shaped items is to wet a paper towel with the required solution and lay it on the surface. Perhaps you could then put plastic wrap over it to keep it from drying too quickly.

Kent"

Right, or just stick it in a big black contractors bag and tie it shut. The reality is you could probably even repair damages to a plastic case with some sort of modeling putty from a hobby shop. To get these things clean though is way more then half the battle though. O the joy.
 
Direct sunlight, in conjunction with bleach seems to work best (in spite of the paradox that the sunlight caused the yellowing in the first place).

The color you're shooting for is a real light beige, with just a hint of yellow. Deeper and pinker than eggshell, but not as yellowish as ivory, or even cream. Anywhere in that range should be passable. BTW, I've seen 'em badly yellowed too, and your description as 'nearly brown' is quite accurate.

--T
 
Terry Yager said:
Direct sunlight, in conjunction with bleach seems to work best (in spite of the paradox that the sunlight caused the yellowing in the first place).

The color you're shooting for is a real light beige, with just a hint of yellow. Deeper and pinker than eggshell, but not as yellowish as ivory, or even cream. Anywhere in that range should be passable. BTW, I've seen 'em badly yellowed too, and your description as 'nearly brown' is quite accurate.

--T
Click to expand...
Here is what I am shooting at getting clean.
PIC00007%7E1.jpg

Saturday, I will take it apart carefully, and set the peices in a clean oil pan filled with 80% bleach, 10% alchohol, and 10% water. And cover it, and leave it.
 
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