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Thread: How to remove spray paint from Mac Plus?

  1. #11

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    That you know of at this point.

    I use brake fluid to specifically modify plastics, at times.

    I'm not saying "don't use it", I'm saying that I only use it for this purpose if something milder won't work.

  2. #12
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    Try ammonia.

    BUT FIRST ... soak a paper towelnin pure ammonia and plop it against an inconspicuous ... such language ...part of the case, probably the bottom. See how it affects the plastic. If no issues, get a tray/bin, lay one side at a time in it, fill with an appropriate amount of ammonia. MONITOR the progress. It shouldn't take long. How it will affect the coating on the inside of the case is for you to determine.

    If the ammonia seems to fail the paper towel test, dillute it with water. There shouldn't be any issues, but it doesn't hurt to be safe.

    There are some paints, epoxy based???, that ammonia won't remove. It made short work of my 5170 case. But my AMT ATjr's case has a different type of paint, and it just laughed at my feeble attempts. I may have to torch it off. Stinky poo.

  3. #13
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    Pure ammonia (NH₃) is a gas at room temperature and is very dangerous.

    The solution (NH₄OH) used for household cleaning is very dilute (about 5% or so). Commercial ammonium hydroxide solutions range up to about 30% and are pretty nasty. Also, don't get the stuff near zinc plate or aluminum parts for any length of time; it's corrosive to those metals.

    High-school chemistry.

    I'd stick with the citrus cleaners first.

  4. #14
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    There's no cause for fear if a test is performed prior to commitment, as I suggested. In my experience, and this is an aside from the main topic, ammonia is the best penetrant I've ever used. But it takes time. If you have something made of steel or iron, soak it from 24 - 48 hours. I guarantee any debris, grit, paint, varnish, 100 year old filler (as used on machine tools and such) will easily come loose if not just run off. It works quickly removing paint, 5 or so minutes is all that's needed.

    Ammonia is very cheap and easy to find.

  5. #15
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    Richmond Hill, Ontario, Canada
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    I am with NeXT on this one. Dot 3 brake fluid has worked will. I even used it on painted metal with some stencil painted school markings over top to remove that stenciled paint. You have to be very careful with timing on this but it worked. Working on plastics has worked for me a few times as well. No issues so far.

  6. #16
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    Thanks everyone for the recommendations! I have a can of paint stripper that I have applied and will see if it does anything to the plastics, the reason I created this thread was if there would be any safer alternatives to acetone and paint stripper but it seems that the case is fine with acetone.

    Thanks everyone!

  7. #17
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    If the paint stripper is solvent based (stinks and/or contains dichloromethane), don't do it--it'll eat your plastic up in no time.

  8. Default

    I wouldn't go crazy with acetone. Plenty of plastics it'll destroy given half a chance. But it will move a lot of paints too. Methylated spirits or other alcohol can work well on some paints too. I'd probably recommend the Citrus stripper, but still be careful with it, over acetone or dichloromethane or methylene chloride strippers.
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  9. #19
    Join Date
    Apr 2015
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    Austin, Texas
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    I'd be interested to know what plastics brake fluid affect negatively, because as far as I'm aware it doesn't seem to do anything bad to common plastics.

    Power steering fluid on the other hand will wreck everything. Rubber, plastic, paint, etc.

  10. #20

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    I'm not a chemist. The best way to find out is to put some brake fluid in a glass jar and let a piece of the plastic of your choosing soak in it for a month. (Seal the jar, or the brake fluid will actually pull relatively large amounts of water out of the air).

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