pfenlon Posted November 6, 2016 Report Share Posted November 6, 2016 I have 4 sidelamp marker housings to paint Satin Black. they are made of a Plastic/Nylon?? material that was originally chromed by some (to me) unknown process. the chromium plating has literally fallen off the rear of the housings, but is still in good order where it shows on the outside. Does anyone have a way of safely removing the plating please. They are off the Red Tomato. Quote Link to post Share on other sites
Don H. Posted November 6, 2016 Report Share Posted November 6, 2016 They're almost certainly ABS (acrylonitrile-butadiene-styrene). It's one of the few parts that's capable of being electroplated and commonly used for things like this on cars and household plumbing. There's a chance it's vacuum-deposited aluminum, too. Still likely to be ABS if so. I'm not sure how I'd remove it -- possibly abrasive. If it's vacuum deposited, it'll come off easily 'cause the film is so thin. Buffing will remove a coating like this. If it's electroplated it will be a rigid film and a lot harder to get off. Quote Link to post Share on other sites
stillp Posted November 6, 2016 Report Share Posted November 6, 2016 Caustic soda? Very good at removing aluminium. Pete Quote Link to post Share on other sites
pfenlon Posted November 6, 2016 Author Report Share Posted November 6, 2016 Thanks already, but, just a note, I do have a broken one, so I could Experiment, i.e. with Pete's caustic soda suggestion. Quote Link to post Share on other sites
Don H. Posted November 6, 2016 Report Share Posted November 6, 2016 Thanks already, but, just a note, I do have a broken one, so I could Experiment, i.e. with Pete's caustic soda suggestion. Google has thousands of suggestions, Pete: https://www.google.com/search?num=50&site=&source=hp&q=removing+chrome+plating+from+plastic&oq=removing+electroplated+chr&gs_l=hp.3.3.0i22i30k1l10.639.7984.0.11809.27.19.0.8.8.0.127.1737.15j4.19.0....0...1c.1.64.hp..0.26.1684.0..0j35i39k1j0i131k1j0i67k1j0i20k1.1isJeVdZZCQ Quote Link to post Share on other sites
pfenlon Posted November 7, 2016 Author Report Share Posted November 7, 2016 Google has thousands of suggestions, Pete: https://www.google.com/search?num=50&site=&source=hp&q=removing+chrome+plating+from+plastic&oq=removing+electroplated+chr&gs_l=hp.3.3.0i22i30k1l10.639.7984.0.11809.27.19.0.8.8.0.127.1737.15j4.19.0....0...1c.1.64.hp..0.26.1684.0..0j35i39k1j0i131k1j0i67k1j0i20k1.1isJeVdZZCQ Thank you for that Don, apparently the answer is household bleach! Didn't think of googling that one, but thanks again Pete. Quote Link to post Share on other sites
pfenlon Posted November 8, 2016 Author Report Share Posted November 8, 2016 Thank you for that Don, apparently the answer is household bleach! Didn't think of googling that one, but thanks again Pete. The bleach wasn't very successful I now want to try Hydrachloric acid, where can I buy some from that doesn't have a brand name i.e. descaled and sink cleaner?? Quote Link to post Share on other sites
Alec Pringle Posted November 8, 2016 Report Share Posted November 8, 2016 Brick acid from the local builders' merchants might be a good starting point ? Cheers Alec Quote Link to post Share on other sites
keith1948 Posted November 8, 2016 Report Share Posted November 8, 2016 Hello Pete Alec just beat me on this post. Was typing my answer when his came through. Hydrochloric acid (HCl) is used by bricklayers to clean mortar marks off bricks. Try a builders merchant. It might work producing a soluble chloride with the 'chrome'. Kettle descaler is usually citric acid which is weaker. Vinegar (acetic acid) is also a weak acid. Would think neither of these is up to the job. Sink blockage remover is usually based on sodium hydroxide which is no good for your job. Bleach is based on sodium hypochlorite. This might adversely affect the 'plastic'. Car battery acid is sulphuric acid (H2SO4) and may well dissolve the 'chrome' plate to form a soluble sulphate. Whatever you use wear eye protection. If you get even one drop of acid in the eye wash it out immediately with lots of water. Also do it in a well ventilated place because the acid fumes can be quite nasty as well. Also wear rubber gloves. Also hydrogen will be generated and this is inflammable. (acid plus metal = salt plus hydrogen). Remember school chemistry popping hydrogen in a bunsen flame? Never tried to do this job myself so not sure if any of these will work but I would try hydrochloric or sulphuric acid first. Failing all attempts I would then just paint over it! Keith Quote Link to post Share on other sites
tthomson Posted November 8, 2016 Report Share Posted November 8, 2016 Your best bet is to use Caustic Soda (NaOH), but getting a strong enough solution for a quick result is difficult, Most of what is sold is a mixture of NaOH and Ca(OH)2, with more of the latter. Good luck Quote Link to post Share on other sites
pfenlon Posted November 8, 2016 Author Report Share Posted November 8, 2016 Brick acid from the local builders' merchants might be a good starting point ? Cheers Alec If it works as well as your Milkstone stuff does at rust removal,were on a winner. So its plan B tomorrow, thanks to all for the advice. Quote Link to post Share on other sites
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