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For most of my life I have been assembling what has turned into a very nice collection of retro machines. For many of my systems I am the original owner, and they are in near-mint condition, but I have just as many purchases from ebay or donations from friends that could use some TLC.

I am familiar with Retr0bright and can see it's application for things like my VIC-20, Apple //c or TRS-80 Model 100. But what other tricks can be used to make your old equipment look new again?

For example, I have a TI-99/4A that has some scuffs in the (faux?) aluminum trim, could those be buffed out? and if so, using what? And what about black plastics that have dulled with age? Is there a safe oil or silicone (that won't ruin them) to bring back their luster?

At the risk of asking an over-broad question; What products and techniques are collectors using to keep their systems looking cosmetically like new?

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    As you have said, this is rather broad. You're asking every single question that could possibly fit in the restoration tag in one question, and that's too much. I notice that you have asked "How can I buff out scuffs in (faux?) aluminium trim?" and "How should I restore dulled black plastics?"; perhaps you should ask these both as separate questions instead. – wizzwizz4 Dec 15 '16 at 21:19
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    Don't do this: old stuff is meant to look old, not a fake "mint condition". You are ruining your stuff. – Janka Dec 17 '16 at 21:39
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    Thanks to the members who answered below! The point of the question was to solicit what I didn't know, not ask about a specific scratch or bump. its can be challenging to ask a question about a tool or technique you've never heard of. - I love all the Stack Exchange sites, but sometimes I think they are a bit over-zealously moderated. At any rate, thanks again to everyone for their constructive input! – Geo... Dec 19 '16 at 11:30
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  1. Old plastic changing colors or damaged

Plastics which have been exposed to the sun often fade because the ultraviolet light breaks down molecules in the surface layer.

Plastics can also age due to exposure to oxygen and other reactive gases in the air, which breaks down molecules in the plastic surface.

Both of these conditions can sometimes be seen if you have very old adhesive labels on a device that were never removed, and the plastic under the label is now a different (original) color compared to the rest of it.

Once molecular damage has been done, there is not really anything that will restore the damaged molecules to their original state.

 

Plastics often have a base color with additional coatings applied as paint, or chemically bonded-on plastics mating two types together into a composite.

The silver trim on plastics can be just a thin surface coating. The principle of buffing is to remove surface damage and reveal more material underneath. But there may be nothing underneath the silver trim except the plastic base color.

Bending or denting plastics often turns them white, and this whiteness condition is not reversible.

You may be able to remove fading with very light sanding to reveal undamaged plastic underneath, but if there is any textured surface finish you will remove it with the sanding. If the backside plastic is not the same color as the front, there is risk that the front side faded plastic layer is very thin, and sanding will reveal the other color.

 

You may have better luck just spray painting the plastic casing with colors that match the original, as this will preserve surface finish without removing material.

Though for consistent appearance you will need to paint the entire surface, requiring you to mask off areas that should not be painted.

Also the paint is unlikely to perfectly match the original color or appearance so you will need to paint all exposed surfaces on all plastic shell components so that their final appearance is the same.

 

  1. Old flexible plastic becoming brittle

Old flexible power cords have a tendency to become brittle and to crack as they age. There is really nothing that can be done to prevent this, and you will have to replace them.

Plastics such as vinyl or neoprene are very hard and brittle in their natural state. They become soft and flexible with the addition of plasticizers generally known as pthalates which are extremely thick and heavy oils that are mixed into the plastic during manufacturing. The plasticizers act like tiny straight coil springs embedded into the plastic and allow it to flex without breaking.

However as the years go by, these springy molecules can work their way out of the vinyl and pop out, evaporating into the air. This is the smell of new plastics that fades over time as it ages.

During manufacturing there are many plasticizer molecules that don't embed into the matrix, but just lay on the surface lightly wedged between other vinyl molecules. These wiggle out and evaporate more easily and are the cause of the strong odor of new plastics.

The more embedded plasticizer molecules stick around for years without an odor, but when they finally work their way out, the plastic becomes very rigid, and starts cracking when flexed.

 

There are products that claim they can restore old vinyl to "like new", but they generally only apply plasticizers to the surface. The chemical in the bottle may not exactly match what was originally used and may not be entirely compatible.

Exposure to pure plasticizers in a restorative can be bad for you, as they have been shown to harm biological processes through biomimicry. Some plasticizers are misinterpreted by organisms as if it were estrogen, which can cause feminization, development of breasts on males, and disruption of sexual processes in young animals when released into the environment.

‘Gender-bending’ chemicals found to ‘feminise’ boys - New Scientist, 27 May 2005 https://www.newscientist.com/article/dn7440-gender-bending-chemicals-found-to-feminise-boys/

A critical analysis of the biological impacts of plasticizers on wildlife https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2873012/

You are better off just replacing old plastic that has become brittle than trying to restore it. Once it has become brittle and cracks, it cannot be mended.

 

  1. Rubber that turns to sticky slime

Some types of flexible rubber have a tendency to age differently, turning from a solid into a slimy liquid. You will often see these as the rubber feet on devices, becoming sticky, and then degrading into a very thick and disgusting runny slime that gets all over everything.

These should be removed as soon as possible when they start to become sticky, and replaced with new rubber. If you cannot find an exact replacement, you can sometimes either just leave it off and don't have them if the bottom of the device won't scratch tables, or substitute something completely different, such as stick-on felt pads used for furniture.

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  • I've heard vinyl paint is good for plastics because it penetrates deep into the plastic and prevents the color from rubbing off. – snips-n-snails Dec 16 '16 at 19:05
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The web is full of many "Retrobrite" solutions. Some are very complex and some are simple. They both seem to provide the same results in the end (from what I've seen). So, given the two, I choose simple.

I own nearly 70 vintage computers and I'm the original owner of about 4 or 5 of them. So it stands to reason that my collection has seen it all. Everything from total destruction to nearly mint.

Anyway, I have developed a pretty good solution that works for ME. Your results may vary.

  • First, I don't worry about restoring everything to absolute mint condition. It's impossible anyway. A few battle scars is OK.

I break the computer down as far as I can. I remove the keys from the keyboard, I take the case apart, etc. I try to gather all of the plastics in one pile that can be thrown in the dishwasher. I just make sure the electronics and stickers are either off or covered.

That alone gets most of the gunk off.

I then perform my own Retrobrite technique. I put all of the keys in a Ziploc bag and fill it with hydrogen peroxide. I used to use the strong 40% stuff. But it's too expensive. I just use the cheap 3-4% stuff and it works fine. I put the bag in direct sunlight and rotate it frequently for most of the day.

This usually gets rid of the most stubborn yellowing. I will repeat the process for the few keys that didn't get a good treatment.

For plastics that I cannot submerge in liquid, I use the stuff people use to bleach hair. The Top Salon 40% gel. It looks like shampoo. I rub that solution all over the plastic and let it bake in the sun for a few hours, rinse and repeat.

IF YOU DO THIS, WEAR PROTECTIVE GLOVES AND KEEP IT OUT OF YOUR EYES! THAT STUFF BURNS LIKE CRAZY...TRUST ME...I KNOW! TAKE EXTRA CARE WHEN USING ANY HYDROGEN PEROXIDE OVER 3%

If the area to Retrobrite is large and flat, I will sometimes just paint it.

That takes care of the outside. For the motherboard, I remove any socketed chips and clean them with 91% IPA. Especially the pins.

If the motherboard is only dusty I will clean the rest of it with cotton swaps and 91% IPA. If the mother board is filthy I will wash the board with water and soap. (Yes, you can do that...just make sure any batteries are out).

To wash the motherboard, I use a gallon of distilled water. Distilled because there is slightly less chance that it will dry and leave residue and deposits. But I take a shallow baking pan, pour the water all over the board and then pour the dirty water down the sink. I will then put the board in the pan and submerge it with the distilled water. I then add a few drops of dish soap and scrub the board (GENTLY) with a toothbrush all over. Both sides.

When done, I drain the soapy water and then clean out the pan so there are no more bubbles or soap in the pan.

Next, I submerge the board in distilled water again. I lift the board up and down, side to side, etc. so that the water flows all over the board in each direction so that it gets a good rinse.

I drain the pan and repeat a couple times.

I also make sure I directly pour the water into slots, under IC's, etc. to push out any soap residue.

When clean, I take the board outside and gently swing it around (holding firmly) to remove any large deposits of water. I might also take a paper towels to get rid of the obvious puddles.

Finally, I run a hair dryer over the board with the speed set to high but the temp set to cold. Cold air is better at evaporating water over a circuit board.

After I have dried all of the obvious water with the hair dryer, I will sometimes put it outside for a few hours if the humidity is low and no chance of rain.

I wait at least 48 hours before I put power to the board. By that time, it's bone dry and clean as a whistle.

If your board has lots of corrosion from batteries or capacitors, that's a different cleaning process for a different question.

I then reassemble the board and it's like I got a new computer. Makes me feel like it's 1983 again and computers were great and mysterious.

That's how I do it. I haven't found a way to take out scratches. But, I haven't exactly looked either. I don't mind some cosmetic imperfections. I just make sure I actually play with my computers.

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