Removing really old sheet metal protective film

[Aluminum]

Originally Posted by Zazoos

I let Aircraft paint remover sit on it for 30 minutes. Wiped right off without phasing the adhesive film.

This is odd. What brand of remover? You want one based on dichloromethane, like this one: https://www.homedepot.com/p/Jasco-1-...0202/202247418.
Wear protection.

Here are some more solvent ideas:
https://www.plasticsintl.com/chemical-resistance-chart

[wjb]

I've found that orange oil does a fantastic job cutting through the goo when all the other solvents (alcohol, acetone, MEK, paint thinner, etc) fail. I can get a can of the stuff in the bike section of my local REI (outdoor equip) supplier

This is the stuff:

http://www.finishlineusa.com/product...hain-degreaser

Seems to do magic when other things don't ... and it smells nice!

[-goose]

I had exactly this situation with the white vinyl and also some blue that had baked hard after a fews years of sun through the workshop window. After no luck with MEK I left some of that heavy duty yellow paint stripper on it for 24hrs. It softened it just a little, not much but enough to be able to scrape much of the plastic off with a perspex scraper. It was heavy going and took a lot of scrubbing afterwards with scotchbrite to get the remnants off and remove scraper scuffs and scratches. I seem to remember orbi sanding as well.

After that the whole plane was scotchbrited thoroughly during paint prep.

So unfortunately it may be a pretty manual process for you unless some of the other posters' suggestions bear fruit, best of luck.

Next time the plastic will be coming off out of the box!

[Zazoos]

Originally Posted by Aluminum

This is odd. What brand of remover? You want one based on dichloromethane, like this one: https://www.homedepot.com/p/Jasco-1-...0202/202247418.
Wear protection.

Here are some more solvent ideas:
https://www.plasticsintl.com/chemical-resistance-chart

Thanks for all the help. The JASCO Paint and Epoxy Remover works like a charm. I let it sit on there for about 12 hours and then scrape with a piece of plexiglass. Doesn't even take much scraping to get it off.

[AV8ER]

Thanks for the suggestion Bill although I am looking to preserve the paint that is still serviceable under the dried decal so I think the paint stripper will remove the old plastic protector AND the underlying paint. Possibly some of the other products in your linked discussion may work. I will make a list of them from it and check them out.

Originally Posted by N941WR

WD40 helps. That is about the only thing that stuff is good for.

[N661DJ]

I find the following works well:
Lightly abrade the surface of the white plastic with course sandpaper, apply liberal amounts of Aircraft Paint Stripper, brush it on, cover the area with "cling wrap" or a similar product to prevent evaporation, use a plastic "Bondo" spreader
to remove the residue, you might have to hit a few of the difficult places again.
I have used this method with good results.
Dick