Cleaning headlights - 100% IPA dissolves plastic?
Discussion
Hi all,
I'm breaking a car and have taken the plastic headlights off to sell. They were milky with oxidisation so I wanted to clean them up.
After wet sanding with 800 and 1200 grit, I have washed and cleaned and washed and cleaned repeatedly to remove any plastic residue.
The next stage is to go over it with isopropyl alcohol to remove any contaminants. I bought 100% IPA, not the 70% stuff.
It's at this stage that I'm flummoxed. I can clean it with water 'til there's no longer any white residue on a black piece of cloth. I then go over with a nice clean cloth with IPA and while it's wet it looks lovely and clear. But immediately it becomes cloudy again, leaving powdery trails where I've just applied the IPA. I can just about rub this powder off with a clean cloth but it's a lot of work.
I can only conclude that either the washing isn't working (and I've REALLY tried to clean it) or the IPA is dissolving the plastic and leaving it to dry on the surface. I have tried first using meths and then IPA, and the same happens.
The only way I can get a decent clear finish prior to me clear coating is to use meths on its own, but that will leave a residue being a mineral-based solvent (or at least the guides tell me.)
I've had to wet sand several times as the clear coat I had first was terrible, leaving a crinkly surface rather than a gloss.
I'm breaking a car and have taken the plastic headlights off to sell. They were milky with oxidisation so I wanted to clean them up.
After wet sanding with 800 and 1200 grit, I have washed and cleaned and washed and cleaned repeatedly to remove any plastic residue.
The next stage is to go over it with isopropyl alcohol to remove any contaminants. I bought 100% IPA, not the 70% stuff.
It's at this stage that I'm flummoxed. I can clean it with water 'til there's no longer any white residue on a black piece of cloth. I then go over with a nice clean cloth with IPA and while it's wet it looks lovely and clear. But immediately it becomes cloudy again, leaving powdery trails where I've just applied the IPA. I can just about rub this powder off with a clean cloth but it's a lot of work.
I can only conclude that either the washing isn't working (and I've REALLY tried to clean it) or the IPA is dissolving the plastic and leaving it to dry on the surface. I have tried first using meths and then IPA, and the same happens.
The only way I can get a decent clear finish prior to me clear coating is to use meths on its own, but that will leave a residue being a mineral-based solvent (or at least the guides tell me.)
I've had to wet sand several times as the clear coat I had first was terrible, leaving a crinkly surface rather than a gloss.
The guides I saw said just to leave it at 2000 grit to give the clear coat something to grab on to.
E.g.
https://www.youtube.com/watch?v=UEJbKLZ7RmM
Edited to change 1200 to 2000 grit.
E.g.
https://www.youtube.com/watch?v=UEJbKLZ7RmM
Edited to change 1200 to 2000 grit.
Edited by V8S on Thursday 9th June 18:50
waxaholic said:
Ok wiping down with ipa after sanding will leave a dull surface, if your not going to machine polish then use a finer grade of paper before clear coating, TBH i wouldnt renovate headlights in this manner and expect a good result, sanding marks will appear under the clear coat, machine polishing and a coating will yield better results imo.
From all the guides I've read and watched, they seem to get really good results just doing what I've described. It's very frustrating when you try to do as good a job (if anything I've spent longer getting it smoother with 2000 grit) and cross reference guides to make sure they agree, and it still comes out crap. At this rate it'll have cost me more to tidy them up than I'll get selling them!I've done it again tonight with a new can of Rust-o-leum gloss clear coat and at the moment it's still all bumpy after three coats. Guides seem to suggest that it'll clear after a day. I'm not convinced. It didn't before with the stuff from B&Q. Valspar or something.
If it doesn't work this time, I think I'll just take off the clear coat and use some 3000 followed by some polish and sod the things.
I am so so so close to ordering the DAS6 Pro as mentioned in my other post. It usually takes me several months of umming and aahing to decide and buy something. I'm only 2 months in!
I just think, once I've done my two cars and these headlights, I'll have an expensive machine sitting doing nothing for 6 months until the car maybe needs a light polish. Just seems a huge amount of money to tie up at the moment.
I just think, once I've done my two cars and these headlights, I'll have an expensive machine sitting doing nothing for 6 months until the car maybe needs a light polish. Just seems a huge amount of money to tie up at the moment.
I have a drill buffing attachment and some Meguiars deep crystal polish which I might try on a slow speed.
Obviously I don't want to wreck the lights because I want to sell them, but equally I don't want to end up spending more on products than they're worth!
The lacquer is still all bumpy and crazed.
Obviously I don't want to wreck the lights because I want to sell them, but equally I don't want to end up spending more on products than they're worth!
The lacquer is still all bumpy and crazed.
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