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Removing Yellowing from Plastics - Part 3

linemanduke said:
this has probably asked but im a slow reader lol. will this mixture remove lettering off the plastic such as the //c on apple 2cs or the labeling on the front of my samsung?

also i have some black dell laptop pieces i can sacrifice. :)
Click to expand...

I got a small amount of letter fading on my Apple IIe Platinum. Not much and it was acceptable...but it did occur.

Tez
 
The sacrificial piece is coming from a "parts" Osborne.
It is a parts Osborne because I warped a keyboard case, and one other plastic part, while de-yellowing in 115 F temperature, with direct sunlight where the solution temp was 145 F.
So, it's really no loss. Besides, Osborne 1a's are a dime a dozen, and that's what they get for using such cheap plastic.

We're doing all this, so we can figure it out before we try it on something really valuable.

The paste/gel will remove paint off labels (plastic or metal/foil), and messes with metal too (although not that bad). If the metal is visible, I wouldn't do it. If it's a bolt, I wouldn't worry about it.
Paper or foil backed labels will be destroyed. I have taken to removing all labels and re-attaching them - if it's something you want to look like it did before, remove the labels first.

I think Dell plastic is too new, and not "yellowed" enough to be a good subject.

I'm going to use a blue Osborne keyboard bezel (instead of the face plate), and will start the experiment tomorrow morning.
 
ok cool i guess so says 1989 but i can understand how that wouldn't be as yellowed "looks over to the now orange face plate of the 1989 samsung"
 
@ Merlin:

Wow!
That Wiki looks great.
I love the new look, and there's some interesting reading in those links too.
Very, very well done !

PS: I wonder why there's more science tabs than any others ? :)
 
Small steps Lorne, small steps.... it makes it easier to follow and digest.

Now all I have to finish off is The Gallery....

:mrgreen:
 
Help!

A French forum at system-cfg.com has made contact and they are working on cleaning their retro kit. I am trying to help as best I can but my French isn't 100% by a long way.

Is there anyone on here that could help me translate the Wiki into French?

Thanks
 
Merlin said:
Would you like me to start playing 'The Last Post' :(?
Click to expand...

You don't need to play 'The Last Post' for the Osborne piece, but we might need to play it for the Powdered Bleach mixture (& maybe for the mix with the Isopropyl Alcohol in it, as well).

I wanted to wait and take the "after" photo at the same time of day, and in the same light as the "before photo".

Here's the dark blue Osborne keyboard bezel before:

Osborne keyboard bezel - before.jpg

Here's where I applied the paste/gel:

Osborne keyboard bezel - paste-gel applied.jpg

And here it is after 6 hours:

Osborne keyboard bezel - after.jpg

If you can see the difference, you've either got better eyes than me, or you're on drugs.



There've been four occasions where I had undesired results with dark blue or black plastics.

I couldn't believe that it worked alright this time, so I went back in time, to Part 1 and Part 2.

On the last page of Part 1, and on the 1st page of Part 2, I was deyellowing a white and black Televideo 925 monitor. I had undesireable results twice on the black parts. I was using the powdered bleach mixture.

On page 19 of Part 1, some black plastic on the face of an Altos 5/15 was lightened. I used Isopropyl Alcohol in that mixture.

There was one other instance (using a dark blue Osborne keyboard bezel) where some plastic got lightened, when I did'n't want it to. This one was not documented in the threads, but it occurred around the same time as I was using the isopropyl alchol mix.


So, it appears from this little experiment that it may be safe after all, to use the Xanthan Gum mix on dark plastics. I've got a rebadged Televideo 950 coming (one day soon, I hope), and I can try the mix on an interior section of that piece's black plastic.

Merlin: if you go back and have another look at the ingredients in the PB, can you see anything now, that you think would have caused the dark plastics to lighten? Same with the Isopropyl Alcohol - knowing what we know now, can you see any chemical reactions that would confirm that these undesired results should indeed have happened.

.
 
@ Lorne

If you read back I said that there were some solvents such as terpenes in the PB that could potentially de-nature the surface of the plastic; I think that's what you saw originally with the dark blue part. Solvents are to be avoided really with plastics and that's why I went for Glycerine.
 
Merlin said:
@ Lorne

If you read back I said that there were some solvents such as terpenes in the PB that could potentially de-nature the surface of the plastic; I think that's what you saw originally with the dark blue part. Solvents are to be avoided really with plastics and that's why I went for Glycerine.
Click to expand...

OK - that's that mix done with then.

How about the isopropyl alcohol?
Does that do the same thing as the solvents?
(I know you said at the time, that one was somewhat dangerous, but I was looking for the "speed booster").

I'm just trying to rule things out.
 
Iso Propyl Alcohol isn't strong enough to attack the plastic, you should be OK with using IPA. I used to use IPA or methylated spirits years ago to help disperse hydroxy ethyl cellulose in water, so the application is valid.
 
I'm trying a new approach

I'm trying a new approach

I don't know if this is going to work or not. I mixed the hydrogen peroxide and oxy-clean into a spray bottle. I put the VIC-20 case in my bath tub and a UV light above the tub. Then I just sprayed the mixture onto it every few minutes to keep it wet. I'll let you know how this works.
3316031847_f3a23da950.jpg


3316032321_e29d0c8823.jpg
 
Hi,
I followed this discussion carefully, but because I don't speak easily English, I have not yet participated.
I just wanted to show you some results.

H202 12 to 18%, Oxy 1% and sun.

Each photo 1 hour
H2O2_test6_full.jpg


and before, after
H2O2_vic20_1.jpg

H2O2_vic20_2.jpg

H2O2_vic20_3.jpg
 
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@adric22:
That's looks like it's going to be labor intensive, having to keep spraying the parts as the solution evaoprates, but it's worth a try. (I've been trying to figure out where I could get a sprayer that would allow me to spray a paste/gel instead of brushing it on). Keep us informed.

@fneck:
That's fantastic. I love the progression photos of the keys. That is very informative. Hourly photos - great idea. Très bien.

@Merlin:
The gallery looks great.
(You should put fneck's progression photos in there too).

And here's two more (of a TRS-80 dot matrix printer) for the gallery.
(I used the Autoglym stuff on the blacks parts - they turn out real nice)

TRS80 printer - before - comp.jpg

TRS80 printer - after - comp.jpg
 
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LOL, do you realise how many pictures I have collected so far? The Gallery is going to be BIG, bigger than a big thing with big things sprinkled on top....

:lol:
 
adric22 said:
I don't know if this is going to work or not. I mixed the hydrogen peroxide and oxy-clean into a spray bottle. I put the VIC-20 case in my bath tub and a UV light above the tub. Then I just sprayed the mixture onto it every few minutes to keep it wet. I'll let you know how this works.
Click to expand...

Double hmmm, not sure how the fiberglass tub is going to like that treatment!! I have a tub like and screwed up. I put a full bottle of clorox into the tub when I was cleaning. The tub wasn't used for many months and when I got back, I had found the the bleach had leaked out of the plastic bottle.

To this day, I have this UGLY half moon grayish white area where the bleach messed up my tub.
 
I guess every beat up and yellowed computer is now going to be new never used on ebay with this cleaning method.

Come summer when we have perfect sunlight and I am out grilling or doing yardwork daily anyway, I will try the outdoors spray on method (since it only takes a few hours to work) on my 1040 ST that is yellowed. I do have a mac IIfx case that is yellowed and could use a cleaning but I would have to rip out all the metal thats rivited into the case for that to work (or the peroxide is going to corrode it).

Anybody going to bother documenting what the cases look like 6 months to a year after the cleaning to see if they are yellowing again?
 
Some great results there.

Vic-20s in particular seem to take to these treatments particularly well.

Nice to see a timeline with the keys.

Things are pretty busy in my life at the moment, but I have recently bought some Xanthan gum so I could try the alternative (or maybe I should say mainstream) paste recipe rather than Arrowroot.

The gum wasn't easy to find. In the end I picked up some at a organics health shop. I've also sourced a UV light, so this time the treatment will be more controlled.

A colour genie is next on the hit list. I'm not sure when I'll get around to it as I've got a few other things which have a higher priority at the moment.

Tez
 
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