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Aiii. Ugly paint!

tjjq44

Well-known member
More seriously, You could try rubbing alcohol, I use it on dirty macs it doesn't harm, but never use acetone!! It melts plastics!!

 

BadGoldEagle

Well-known member
Yeah, I'd use brake cleaner as well to get it off.





Try it on a small surface first (on the bottom for example), just in case...

 
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jessenator

Well-known member
They didn't start adding acetone to DOT brake fluid did they? ;) Kidding. There are too many plastic components in a brake system for that sort of formulaic change.

I wish I had a truly "beater" case that I cared nothing for so I could go hog wild on various, unconventional cleaners... I guess I have a Classic I case I'll never really use. It's just a box for holding my se/30 spares, tbh. Though it still is amazing shape and has little if any discoloration.

Definitely like BaldGoldEagle suggested, test just a bit on the bottom of the case, if you do go that route.

 

Trash80toHP_Mini

NIGHT STALKER
If it's acrylic spray paint you may be in luck, if it's olde schoole lacquer based spray paint you're probably not.

How to remove krylon spray paint

The most interesting hit was Method 4

Apply carnauba wax to the spray painted area. Squirt several generous dabs of wax onto a clean sponge. Rub the sponge over the spray paint using circular motions. The wax contains oils that should start breaking down the spray paint almost immediately.[9]

  • Carnauba wax is also called Brazil wax. Look for a product marked 100% carnauba or Brazil wax at your local home improvement or automotive store.
  • Reapply more wax and use harder pressure to remove stubborn patches of spray paint.



Stay away from Lacquer thinner, one of the ingredients is Acetone, you want to stay entirely away from the Ketone family which includes Acetone. I've used Xylol (Xylene) which is a different chemical family and not as strong a solvent for cleaning up some paints and silk screen inks back when Acrylics hadn't yet come of age. Back in the Dark Ages, all Krylon I knew of and used was Lacquer based, that would be Apple II thru G3/G4 eras.

http://www.differencebetween.net/science/difference-between-acetone-vs-xylene/

https://www.ehow.com/list_6868703_relative-cleaning-strengths-solvents.html

They are all really bad for you. Use only outdoors and preferably wearing a full fledged respirator, masks won't do unless they're top flight, specifically made for solvent vapors. Good luck finding anything but real respirators on the shelves anywhere of late.

I'd apply some Acrylic and Lacquer based spray paints to the inside of the case if I had no other test piece and give all the methods a whirl where it doesn't show.
 

mactjaap

Well-known member
I used the Dot 3 tip as described. What a success! Almost gone is this ugly paint. 
See the result. 
 

395F0293-1BD3-4785-92A3-8B2F27D0F971.jpeg

 

joshc

Well-known member
Looking good. I wonder if retrobrighting would get rid of what's left as it's so faint now? I don't know why I think this, there's probably no reason it would, but...

 

mactjaap

Well-known member
Yes. Some yellow layer remains. Not much. But still some yellow glow. Would be nice if I could get this off too. Suggestions? Retrobright?

 

jessenator

Well-known member
Retrobright?
Just be careful with it if you do go that route. I did the Salon peroxide + water and heat method and my mouse ended up like Casper :/  
FDysrbv.jpg.bdc9ec300b9ee7c1e87188a8a72832bc.jpg


But I've seen good results from others who've done it. I did the fascia of my 4400 under a blacklight, and that was okay, if a bit time-consuming (painting on more paste every so often). Most people have luck with the plastic wrap or plastic bag, but that seemed just as labor intensive. What I liked about the blacklight method was that it was SLOW and I could control by the hour what level of "bleaching" level I could achieve.

A well-documented series of tests performed by a university(?) in Denmark seem to suggest that in the long-term it might to more harm than good for the integrity of the plastic itself, but for the short term, aesthetic desires, it's probably the only option to get the original coloration back. I can't find that study at the moment, but it's out there...

 

LaPorta

Well-known member
Unless it is horrendous, I have erred on the side of caution and just left my collection as is. I am far more concerned with them working well and not having serious defects (scratches, gouges, imprints) than I am some yellowing. To each his own, but that is my route. We will never have real results because even if you, say, took one case today and retrobrited it and another that you didnt, and crushed them and measured how many newton meters of pressure it took crack it, there would be no experimental control since both cases have probably had ~30 years of different storage conditions. You would need to manufacture a test subject, store them in the exact same conditions for a set amount of time, then retrobrite one and do the test. Even then you would need successive tests to get a sample size that would tell you meaningful results.

In essence: no one will be able to tell you with scientific proof that the process makes plastic brittle. You just have to weigh the risks/benefits on your own.

 

cheesestraws

Well-known member
I am far more concerned with them working well and not having serious defects (scratches, gouges, imprints) than I am some yellowing. To each his own...
I think this kind of discussion shows up an interesting "split" (really a continuum, of course) in the reasons people do play with retrocomputers.  I never retrobright my computers at all; and this is partly because I don't really know how to, but mostly because I don't really have any urge to; it's fine, by me, if old objects look old.  And this is partly because I'm not doing this for nostalgia's sake; I have no desire at all to revisit the times when I used the classic MacOS regularly.  But, generally, the same qualities it had then that I liked, it still has.

But, of course, if one is wanting to recapture the feel of the time when one was using the machines new, then the aesthetics and feel of the case become very important, and especially one does not wish to be jerked out of one's reverie by the obvious agèdness of the case.  And I've seen some arguments that got extremely... personal between people who didn't seem to be able to vocalise or understand that actually the same kind of computer was meaning two different things to each of them, even though they were doing very similar things with those computers on the surface.  And sometimes these people have very different attitudes to old objects in general.  Which is very interesting for other reasons...

Sorry, this got a bit off-topic, but I do think is interesting :)

 

mactjaap

Well-known member
ago, LaPorta said:
I am far more concerned with them working well and not having serious defects (scratches, gouges, imprints) than I am some yellowing. To each his own...
I’m afraid I’m misunderstood. The is a little bit yellow PIANT still on the surface of the ED case. This post is not about retrobright. Nor do I think Retrobright is a way of getting the residu yellow paint of. 
 

So to get readers on the right track again.......
 

Once I had ugly yellow paint on my ED case. Now it is off. Thanks to soaking it in Dot 3 brake fluid ($2,50 for 250ml). But... still some “yellowish” residu remains. 
 

How to get this of???

 
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