Plastic Repair?

Rookie (24)

01-09-2020, 20:34

Hello Guys!

I have a number of old MSX computers and accessories and they show scratches and cuts in their plastic shells, like the one shown here.

I cleaned this FDD back cover using IPA and Windex, but it still shows marks. These marks are not dirts and residue, but scratches (shallow cuts) in the plastic itself.

Any idea how to recover this? I hope we share tips, techniques and chemicals to restore these gems.

Thank you.

By Wild_Penguin

Hero (644)

01-09-2020, 21:01

AFAIK really only feasible way to get away scratches from plastic is to sand and polish the surface. Start with something coarser (coarse enough to sand away the deepest cuts you want to get rid of) and gradually go towards something less abrasive. As a last step use something very very fine polishing paste, people have even used toothpaste.

However, be aware this will of course grind away some of the plastic. Any details might get lost, such as the sticker you have there (better protect it with something sturdy). I would consider if restoring the cosmetic condition this way is really worth it; you are risking to damage the plastic further. But maybe I'm just too cautious about inadvertently damaging retro gear...

By meits

Scribe (6577)

01-09-2020, 21:59

check this and decide whether it's an option.
This guy goes to the extreme.

By fenama

Expert (75)

16-09-2020, 17:33

I eliminate similar marks with this

https://www.amazon.es/esponjas-m%C3%A1gicas-melamina-cubiert...

By tech

Rookie (24)

26-09-2020, 03:49

Thank you all guys.

I got NOVUS 7136, which is a 3-steps plastic repair kit, from eBay. It almost did nothing to plastic shell in hand. So, I tried the synthetic sponge suggested by @fenama. It's called "the magic sponge" in my local market. The sponge did very well in cleaning the plastic throughly and even mitigate scratches. Here is the drive after cleaning:

By albs_br

Champion (499)

26-09-2020, 05:17

It looks like brand new. Nice job.

By Wild_Penguin

Hero (644)

26-09-2020, 11:57

Nice!

By sdsnatcher73

Enlighted (4320)

26-09-2020, 14:11

Magic sponges ordered

By friguron

Master (188)

27-09-2020, 01:30

WTF !! what is the black magic behind this product?

By gdx

Enlighted (6445)

27-09-2020, 02:13

Beautiful! Other sides must be more difficult to clean.

By Wild_Penguin

Hero (644)

27-09-2020, 09:56

friguron wrote:

WTF !! what is the black magic behind this product?

Not sure you actually want an answer of if that was rhetoric ;-) . Anyways, it's melamine sponge/foam. The sponge has very fine, but rough surface and breaks down when you rub something with it. Result: abrasion and polishing.