CONFIRMED: DOT 3 Brake Fluid can clean Lisa plastics

[CelGen]

For the last year I have been figuring out how to get this black spraypaint off a Lisa I picked up.



I thought of using everything from rubbing alcohol to a pressure washer but the success came on a retrial. Previously I had applied DOT 3 brake fluid which seemed to soften the paint a little but not enough to make it worth it, however when I picked up another bottle for free, I decided to try again, but this time instead of leaving a small pool of brake fluid on the panel I took a piece of kitchen paper towel and totally soaked it. After that I placed it down on a panel and left it alone for about three hours. When I returned to check on it I found the black paint had wrinkled which meant it was already well into lifting the paint off.
But how well was it working?




VERY WELL.
Not only had the paint been lifted out of the texture in the plastic but it was also so well stripped that with a small putty knife I could literally scrape off mounds of the black sludge at once with no problems. The brake fluid did not attack the plastic at all.

[mcdermd]

I like this. Filing it away in my brain for future use.

[CelGen]

Okay, here's the process I used to remove the paint.

The experiment consisted as follows:

-A bottle of DOT 3 brake fluid
-Metal cookie tray (grab an old or a cheap one because you don't want to use it again after this)
-Cheap non-synthetic paintbrush
-Paper towel
-Small Plastic container (a small peanut butter or jam jar will do)
-Putty knife

Start off by placing the panel on the tray and start using the brush to cover the panel with brake fluid.


Once that's done, place a sheet of paper towel on top and soak it using the paintbrush and more brake fluid. The paper towel helps keep the panel soaked by preventing the brake fluid from easily flowing away and into the tray.


Leave the panel alone after this for a few hours.
I came back and checked on my piece after four hours and lifting up the paper towel showed that the black paint had wrinkled which meant that it had been stripped off the panel.


Now take off the paper towel and if you have more pieces, put it in the tray under the panel so it does not make a mess, otherwise put it in a bag and throw it out.
Now take the putty knife and start scraping the paint. You should not need much effort and the result will look like this:

The paint will have completely separated from the plastic leaving a skin of black sludge.

Continue scraping off the sludge and use the small jar to put the toxic scrapings into.



Once you have scraped off all you can (there will probably be a few places where you can't get the paint to come off) you can take the garden hose or something with a sprayer and blast off any residue.


You can see that for the most part it was a total success with the exceptions where I didn't properly coat or in the vent grilles. For the most part you can get the last of it off using a bit more brake fluid and a toothbrush but otherwise the plastic is fine.
I have no idea however if this will work with specialty plastic paints. Probably not.

[mcdermd]

Anything special to thoroughly clean the brake fluid off or just detergent?

[CelGen]

I just sprayed them clean using a garden hose with a flat nozzle.

[CelGen]

BuMP.
Dollarama now sells 133ml bottles of DOT 3 brake fluid for $1. I bought 20 bottles and some magic erasers. The panels take a day or two for the stubborn stuff to rub off but the final rinsed pieces look almost untouched.

[CelGen]

Finished product:



Still a few spots that didn't rub out but I'm totally satisfied with the results.

[mcdermd]

That is pretty amazing. Congrats on a fine looking Lisa!

[jsarchibald]

I can confirm that this works for extremely permanent marker, albeit slowly. I came across a HD20SC that someone had written '110V only' all over it, which is stupid because it is a 100V - 240V machine. It took many applications, leaving it to soak it, light rubbing with a toothbrush, but nothing else would even touch it, let alone remove it. Highly recommend the old brake fluid trick!

[krye]

Doesn't using the magic erasers dull the finish to an almost matte-like look?

I had a 512K that I ruined trying to retr0brite. I made the solution way too strong and I cooked the thing. It was all white and ashy. I took a fine grit sandpaper to it thinking I could just take a thin layer off the top to expose the beige underneath, but the whole thing looked terrible after that. The sandpaper basically made the case smooth. It removed that bumpy/textured finish that it had and left it with a dull-matte finish.

[CelGen]

So long as you don't rub like a madman it does not damage the plastics. The brake fluid alone lifts most of the paint. The only reason I used a magic eraser was because it can remove any loose material that's in a tight spot I otherwise can't reach.

[mcdermd]

For "permanent" Sharpie marker, I use a 50/50 mix of isopropyl and acetone. It will not harm plastics (even clear plastic) and takes off most anything.

[tt]

For "permanent" Sharpie marker, I use a 50/50 mix of isopropyl and acetone. It will not harm plastics (even clear plastic) and takes off most anything.

I use dry erase markers, the solvent in them usually does the trick.

[mcdermd]

I'll put that tip in my tool belt

[Trash80toHP_Mini]

Great thread, nice tips-n-tricks in here, keep 'em rollin' in gang!

Nominated for stickie honors in the Hacks & Development forum. Bunsen?

[Bunsen]

Done.

[beachycove]

Great find, and I may have a use for this on a Classic case that has been spray painted. However, a small reminder: Brake fluid removes paint for a reason, the reason being that it is corrosive. That is why it has been known to blind amateur mechanics who get it splashed in their eyes. So take care!

[aftermac]

For "permanent" Sharpie marker, I use a 50/50 mix of isopropyl and acetone. It will not harm plastics (even clear plastic) and takes off most anything.

I would be very careful with Acetone... I ruined the front panel of my Quadra 950 a few days ago.

However, a couple things that I did discover as a result are that Rust-oleum "fine-textured" spray paint very closely matches the original texture of the case, and Testors Flat Light Aircraft Gray spray enamel is a near perfect match for Macintosh Platinum. Both colors lay between Pantone 420-421. This will also come in handy with another project I'm working on. I have an SE that I had to use plastic filler to repair many deep gouges to the case, and I've been trying to figure out how to restore the texture and color.

Next we'll see how a custom ordered rubber stamp (which I Photoshopped with Apple Garamond, and perfectly aligned and sized) works to restore "Macintosh Quadra 950" to the front panel.

[mcdermd]

Straight acetone will murder ABS plastic (if you want to do some fake plastic welding, acetone works pretty well). Diluting with an equal part of isopropyl will keep it from doing any damage.

[aftermac]

Straight acetone will murder ABS plastic (if you want to do some fake plastic welding, acetone works pretty well). Diluting with an equal part of isopropyl will keep it from doing any damage.

Yup, found that out the hard way. Lesson learned. I am pretty pleased with the repair job so far, however.

[Trash80toHP_Mini]

Straight acetone will murder ABS plastic (if you want to do some fake plastic welding, acetone works pretty well).

That'd be relatively ineffective plastic fusing if tried with acetone. It's done properly with a MEK, usually with acrylic in solution to thicken it up a bit. It's also called solvent bonding.

Plastic welding involves compressed air, heated in the welding gun and welding rod made of a compatible plastic. Strips of Mac or PowerBook Case Plastic for our uses.

< reminds self to get the rig out to practice and take some pics of the MacWelding process >

[mcdermd]

Yeah, I'd like to learn some real plastic welding sometime. It has always seemed like something useful.

[Dennis Nedry]

The thought crossed my mind of using brake fluid on a spray painted 7100 and it should be noted that this would be a huge mistake on the metal part of the computer, as it will remove the original paint as well!

I feel reasonably good that retrobrite won't remove non-sticker labeling that's printed directly onto Macs, i.e. "Macintosh", "Power Macintosh", "Macintosh Quadra 700", etc. Has anybody seen what happens to these labels in the presence of DOT3 brake fluid? Even rubbing alcohol dissolves/smears these labels slightly sometimes.

[onlyonemac]

Why would someone do that to the poor Lisa anyway? It looks horrible with all that paint on it !