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alexkerhead
March 27th, 2006, 09:16 PM
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.

Terry Yager
March 27th, 2006, 09:35 PM
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

DimensionDude
March 27th, 2006, 10:06 PM
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

CP/M User
March 27th, 2006, 10:16 PM
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.

alexkerhead
March 27th, 2006, 10:21 PM
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.

DimensionDude
March 28th, 2006, 02:52 PM
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

Chris2005
March 28th, 2006, 04:42 PM
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

alexkerhead
March 28th, 2006, 07:07 PM
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.

Terry Yager
March 29th, 2006, 01:15 AM
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

alexkerhead
March 29th, 2006, 07:25 AM
Humm, good idea, I will see if my friend at the local sam's club can hook me up.

alltare
March 29th, 2006, 08:41 PM
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.

alexkerhead
March 29th, 2006, 08:55 PM
thanks altare, I will give those a go.

Chris2005
April 3rd, 2006, 02:38 PM
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

Chris2005
April 3rd, 2006, 02:39 PM
"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)

alexkerhead
April 3rd, 2006, 04:23 PM
Thanks Chris, will give it a go this weekend.

Terry Yager
April 3rd, 2006, 07:01 PM
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

DimensionDude
April 3rd, 2006, 08:24 PM
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

Chris2005
April 4th, 2006, 04:24 PM
"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.

Terry Yager
April 4th, 2006, 08:43 PM
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

alexkerhead
April 4th, 2006, 08:53 PM
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
Here is what I am shooting at getting clean.
http://www.gallery.ubertechworld.com/albums/userpics/10002/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.

carlsson
April 5th, 2006, 12:59 AM
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).
Fighting evil with evil.;)

Chris2005
April 5th, 2006, 02:48 PM
what you have to realize is that you'll never get it with one application of bleach (or whatever else probably). I've been using the Clorox gel stuph, works FASTER then real bleach it seems, but it's "selective" if you will. You can pour on top of a big area, yet when you hose it off/dry it, you'll find there were areas that weren't bleached as much as others. It's got to be done repeatedly it seems. The length of time I left this stuph on didn't seem to matter that much. You can try dunking it for extended periods, but I'm concerned whether long periods could hurt the plastic (probably not, but who knows). Give this gel stuph a try. You'll find the speed at which it works gratifying.

Chris2005
April 5th, 2006, 02:52 PM
"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)."

Yes, the bleaching effect of sunlight did occur to me also.

"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..."

Personally, I find some of these things have the most subtle hint of chartreuse, with an o so gentle tinting of mauve. OMG SHUT UP!!! LOL

Saw a truck today, had to buy it on sight. That azure just stopped me in my tracks.

--T

carlsson
April 6th, 2006, 06:34 AM
A Swedish gentleman who used to comment figure skating in the early 70'ties was an innovator when it came to naming various colours. He coined that one skater's dress was "dark white" and a lot more interesting descriptoins. I've read on this forum before that there is a special colour named "digital grey" for restoring digital PDP (and VAXen?) etc. Maybe some colour manufacturer should make a series of grey:

Apple ][-grey, Apple //e-grey, C64-grey, C64c-white, Victor-grey etc etc.

Terry Yager
April 6th, 2006, 07:32 AM
Also needed, a broad range of 'Computer Beige' shades.

--T

Chris2005
April 8th, 2006, 11:23 AM
used some more splash-less Clorox the past couple of days. I've gotten out some particulary nasty brown stains with repeated applications, but to totally get a case to it's original color will take considerable work it seems. The other thing to watch for is weakening the plastic. Some sort of conditioner might be in order (like putting armor all on your dash to counteract the suns bleaching effect). Can't recommend something specifically. Maybe olive oil? Something to restore the oils (which everything has to some degree) that the bleach is undoubtedly taking out.

shirkahn
April 12th, 2006, 12:21 AM
I don't know why I didn't think of this before-
Have you tried using a super fine grit polishing compound, like Mequires jewlers rouge? This should take off what can be taken off safely. I've used Mequires mirror glaze to clean up old bakelite nobs and such on my antique fans.
As to "restoring the oils" two thoughts here- 1- plain old Amour All. I've seen it used to help restore original plexiglass windshield on "fiberglassic" boats. 2- There are products on the market for rejuvinating old rubber. I used some awhile back to resurect the rubber drive mounts in a horribly abused Vaxstation. Can't remember the name though.
3- (whoops I lied about the "2" thoughts) Get a silicon cloth from a gunshop. I tried it on the front of my DAT changer tonight which was looking a little rough and now the surface feels almost new.

Terry Yager
April 12th, 2006, 12:36 AM
I often use the ArmourAll on my laptops. I've also thought that you might be able to use regulation Rubbing Compound, like you use on a cars paint-job, but I haven't tried it because I no longer own a power-buffer, and I ain't about to try doing it by hand. I always used a product called 'Black Magic'. It's a liquid-type compound, not a paste, and it works great on laquer or enamel, and would probably make short work of discolored plastic. OTOH, you might need to go with a coarser grit, if the discoloration goes very deep into the plastic, then finish it with finer stuff.

--T

Chris2005
April 14th, 2006, 12:34 PM
I personally don't recommend any sort of abrasives. First off, it's just probably not worth it. And you're going to mar the surface unless the staining just isn't that deep, in which case a little bleach will do the trick.