Does Retrobrite leave a film?

[1391406]

I bought an AT Model F on eBay about a month ago and decided to clean it today. I applied some alcohol to the back of the keyboard and noticed cream colored streaks on the surface after the alcohol dried. There was also white residue on the rag, as well. Not just a little, either. Does that sound reminiscent of Retrobrite? I've managed to wipe off a good portion of it, but it's extremely tenacious. I haven't been able to remove it completely, because it's required I reapply the alcohol over small areas numerous times in order not to smear the white coating to other areas. Whatever it is, it's a b!tch to wipe off.

Is it possible alcohol is destructive to the plastic on the back of the keyboard?

Any ideas?

[PointyFox]

Clarify "alcohol".  Do you mean isopropanol?  If you do, it won't dissolve most common plastics, but will affect a few like nylon and urethane.

[1391406]

91% Isopropyl alcohol. I've used it on all of my Model M's without incident.

[PointyFox]

91% Isopropyl alcohol. I've used it on all of my Model M's without incident.

Isopropyl alcohol = Isopropanol = IPA = dimethylcarbinol =  2-propanol = s-propanol = 1-methylethyl alcohol = sec-propyl alcohol = iPrOH = Rubbing Alcohol = 2-hydroxypropane. 
That's odd.  Maybe it's dissolving an additive or coating?  I wish I knew what the AT model F was made from

[rootwyrm]

91% Isopropyl alcohol. I've used it on all of my Model M's without incident.

Isopropyl alcohol = Isopropanol = IPA = dimethylcarbinol =  2-propanol = s-propanol = 1-methylethyl alcohol = sec-propyl alcohol = iPrOH = Rubbing Alcohol = 2-hydroxypropane. 
That's odd.  Maybe it's dissolving an additive or coating?  I wish I knew what the AT model F was made from

AND NOW YOU SHALL!
Lower and Upper Chassis: Injection molded ABS
Barrel Plate: Injection molded ABS
1 Piece Keycaps: PBT (Dye-Sub)
2 Piece Keycaps: PBT (Dye-Sub) Upper, ABS or PBT lower (typically PBT)
91% rubbing alcohol will not damage any of these components, though it will thoroughly destroy the label, label laminate, and the ink stamp that should be present on the lower chassis. (Don't worry about the lower chassis ink stamp though. It's really just a QC pass mark.) Otherwise? You can quite literally dunk these parts in 91% without risk as long as you don't have anything else in the mix.

The white residue is ... interesting. Got some photos? It's definitely not the plastic itself.. but it doesn't sound like retr0bright to me.

[1391406]

91% Isopropyl alcohol. I've used it on all of my Model M's without incident.

Isopropyl alcohol = Isopropanol = IPA = dimethylcarbinol =  2-propanol = s-propanol = 1-methylethyl alcohol = sec-propyl alcohol = iPrOH = Rubbing Alcohol = 2-hydroxypropane. 
That's odd.  Maybe it's dissolving an additive or coating?  I wish I knew what the AT model F was made from

AND NOW YOU SHALL!
Lower and Upper Chassis: Injection molded ABS
Barrel Plate: Injection molded ABS
1 Piece Keycaps: PBT (Dye-Sub)
2 Piece Keycaps: PBT (Dye-Sub) Upper, ABS or PBT lower (typically PBT)
91% rubbing alcohol will not damage any of these components, though it will thoroughly destroy the label, label laminate, and the ink stamp that should be present on the lower chassis. (Don't worry about the lower chassis ink stamp though. It's really just a QC pass mark.) Otherwise? You can quite literally dunk these parts in 91% without risk as long as you don't have anything else in the mix.

The white residue is ... interesting. Got some photos? It's definitely not the plastic itself.. but it doesn't sound like retr0bright to me.

Thanks for the info. I'll take a few photos later. I've wiped a good portion of it off of the back. I'm assuming someone attempted to apply some sort of coating in an effort to improve the surface appearance, however the plastic underneath the coating is perfectly unscathed and looks fine.

[1391406]

Pics:

[PointyFox]

Looks like white paint.  Maybe it yellowed and someone painted it white? .. Or someone got bored at the office and painted it with Wite-Out.

[rootwyrm]

Looks like white paint.  Maybe it yellowed and someone painted it white?  Or someone got bored at the office and painted it with Wite-Out.

Yeah, that's my guess too. It probably is Wite-Out or poorly applied paint. The way it's streaking there is identical to what I see cleaning up tar stained keyboards. It's gonna take forever to get clean, sorry to say. I would not recommend trying to clean it disassembled - the ABS tends to become somewhat brittle, so you need all the rigidity you can get right now. Can't say I know a better way to get crap like that off an F or M either. :/

[1391406]

Maybe it yellowed and someone painted it white?

That's the thing. Why coat it when there's absolutely nothing wrong with the plastic underneath to begin with? The back and sections of the front are clean now, and there's no yellowing or scratches.

[1391406]

Looks like white paint.  Maybe it yellowed and someone painted it white?  Or someone got bored at the office and painted it with Wite-Out.

Yeah, that's my guess too. It probably is Wite-Out or poorly applied paint. The way it's streaking there is identical to what I see cleaning up tar stained keyboards. It's gonna take forever to get clean, sorry to say. I would not recommend trying to clean it disassembled - the ABS tends to become somewhat brittle, so you need all the rigidity you can get right now. Can't say I know a better way to get crap like that off an F or M either. :/

I appreciate the input.

[fohat.digs]

The Model F plastic is totally different from the Model M cases. It is much more brittle and has a textured "skin" layer over the actual slick plastic below.

I am very careful with Model F cases, since they crack so easily, and since you are left with slick spots when the surface texture peels off.

Warm soapy water and a sponge (or maybe toothbrush) is the harshest I will go on the F case.

*      *      *      *      *

On a separate note, I have never had much luck with Retro-Brite.

Do you guys use a wide shallow pan? Where do you find one big enough?

And if continuous sunlight is required, how do you keep the keycaps facing up all the time? Mine always want to invert themselves.

Thanks!

[Tarzan]

*      *      *      *      *

On a separate note, I have never had much luck with Retro-Brite.

Do you guys use a wide shallow pan? Where do you find one big enough?

And if continuous sunlight is required, how do you keep the keycaps facing up all the time? Mine always want to invert themselves.

Thanks!

Taking a tip from another poster, I made a Retr0Brite soaking jig using a switch plate from a MY7000 board.  Covering the steel plate with plastic tape (I used packaging tape) keeps it from reacting with the solution, and the switches (with metal bits removed) hold the keycaps in optimal position.

I'll see if I can find the linkage to the original article.  OP used this in a plastic tub with UV light, FWIW.

One note of caution; letting the solution level get too low, exposing the caps, WILL cause a permanent bloom on the plastic.  Learned about this the hard way.  Apparently keeping plastic bits in solution too long may lead to this as well, my experience was with a Tupperware container in sunlight.  Sun evaporated the peroxide solution, and even though I refilled it, I was too late. 

Edit: This is the link to my previous thread, still looking for the thread I copied the idea from.  http://geekhack.org/index.php?topic=42211.0

[rootwyrm]

The Model F plastic is totally different from the Model M cases. It is much more brittle and has a textured "skin" layer over the actual slick plastic below.

I am very careful with Model F cases, since they crack so easily, and since you are left with slick spots when the surface texture peels off.

Warm soapy water and a sponge (or maybe toothbrush) is the harshest I will go on the F case.

Well, they're both injection molded ABS, but yes, the F's formulation is more brittle. Not that the M's doesn't age similarly, just less drastically. They have more in common with the chemical composition than they have different though. The texture differences actually have more to do with the mold and curing process than the chemical composition though.

Basically I treat F's like I treat M13's and M5-2's in that the plastic is extremely fragile in numerous locations and also irreplaceable. But trust me, at the same age, M's and F's will be similarly brittle. Getting the plate off an '87 3151 is harrowing because it's pretty much guaranteed to break the post.

On a separate note, I have never had much luck with Retro-Brite.

Do you guys use a wide shallow pan? Where do you find one big enough?

And if continuous sunlight is required, how do you keep the keycaps facing up all the time? Mine always want to invert themselves.

Thanks!

I really wish I could stand to MAKE the stuff.. I have some beautiful ABS doubleshots that could use the retr0bright treatment.

[fohat.digs]

But trust me, at the same age, M's and F's will be similarly brittle. Getting the plate off an '87 3151 is harrowing because it's pretty much guaranteed to break the post.

Maybe I have just had coincidental experiences with different batches of plastics, but I have owned 10-12 Fs and at least twice that many Ms, and the difference in the cases is night and day.

I have never broken an M case or received one broken in any way. I dearly love the F but the fragile cases are atrocious.

The M plastic just seems very leathery and tough, while well over half, if not 2/3 of the Fs have had serious damage before they even got to me, usually cracks radiating out from inside corners and that surface layer peeling off.

I am terrified of opening up an F AT because of the way the shells clip together at the front. At least the other Fs have metal backs.

[rootwyrm]

But trust me, at the same age, M's and F's will be similarly brittle. Getting the plate off an '87 3151 is harrowing because it's pretty much guaranteed to break the post.

Maybe I have just had coincidental experiences with different batches of plastics, but I have owned 10-12 Fs and at least twice that many Ms, and the difference in the cases is night and day.

I have never broken an M case or received one broken in any way. I dearly love the F but the fragile cases are atrocious.

The M plastic just seems very leathery and tough, while well over half, if not 2/3 of the Fs have had serious damage before they even got to me, usually cracks radiating out from inside corners and that surface layer peeling off.

I am terrified of opening up an F AT because of the way the shells clip together at the front. At least the other Fs have metal backs.

Well, statement stands, and is true. The reason the F's break so much easier is because the shell is so different structurally. Same plastic, just less of it and shaped in a way that's not as sturdy. The M's got more reinforcing ribs, certain vulnerable areas are thicker and so on. Basically, the F was designed as a piece to be thrown on over something sturdy whereas the M was designed as being the sturdy element. End result is that the F is 'just a shell' whereas the M is an actual chassis.

Hence why I basically defecate building materials when it's time to rebuild or clean an '87 or '88 M. The brittleness is nasty enough in the M that because it's a structural element and anchor point, the posts just love to shatter at the slightest hitch. No surprise, it's most evident where there's the least texture as well. (Going back to the manufacturing process and mold as an element of the problem.)
For maximum wet yourself with terror, try rebuilding an M5-1. Not a -2, a -1. The trackball mount is mounted with self-threading screws or clips, depending, and is very thin ABS. It's even more terrifying than dropping the upper shell of an M13. And it HAS to come out to clean the optical sensors. So much fun... ;P

[bitslasher]

Old thread, but I didn't see an actual answer to the original question-- what is the white stuff?  The answer is oxidation.  The outer layer of the plastic has oxidized and breaks down into a powdery residue.  This is not unlike what you see on automobile bumpers that are not painted and exposed to the elements.  These cases do the same thing.  When you put the alcohol on it, you just made it wet and into a messy paste form.  I also have an AT F that had a similar issue as well, although it wasn't that bad.

I have a really old F-122 (Oct 1984) and its case was actually *painted* with textured paint.  I assume all the older boards were done this way.  I don't think any of the AT-Fs were.