Poly Strippa in gel format. Costs about $6.50 US per quart. You'll need about 3, but start with 2. Mine was like yours, baked on by the Mexican sun for 20 years, the last 7 cooked one side until it was cracked and harder than old toast.
The heat Gun basically turns the super thin last layer of vinyl into a hard plastic type material that I can't even scrape off. I have even tried a rubber wheel that the local automotive body shop supply praised. It didnt even make a dent. I have given thought about just cleaning the old vinyl and rough it up with a 3m pad on a jitter bug sander and laying the new vinyl on top of it. I know thats a crappy way of doing it but man if this isn't some tuff stuff to get off. I did a search for the Poly Strippa but I haven't found a dealer for it in the US. I really dont want to damage the original paint underneath the old vinyl so I am leery about using any kind of harsh paint stripper on it.
Listen, d4. I know it is a BEAR to get off but, PLEASE....do NOT put the nice new stuff over the old stuff. You will HATE yourself for doing it. OK...so it's not coming off in an afternoon. Take your time....leave it for a few days if you want ... and then come back and then leave it again for awhile. Just view it as a resto project that you do with love and precision. Trust me....you will NOT like it if you put the new over the old....I don't care HOW well you talk yourself into it.
Have you read the Woodgrain threads? Mineral spirits will take off the adhesive without affecting lacquer-based paint. Any heavy duty paint stripper (gel type won't run as bad a liquid) should work. You might find a brand called "1860" down there. 2 buckets of clean water. One for your hands if you get any on you. One to rinse off the area you just did. After that, use the mineral spirits to do the final cleaning. You should be using plastic bondo scrapers when you remove the gooey, bubbling paint stripper, not steel.
I am not worried that much about the adhesive as much as I am worried about using a paint stripper on it. Again this delaminated down to the layer right before the adhesive. This where the concern with using the paint stripper comes in... I have can of the $30 3m stuff that seems to work but it is very pricey and would tale a ton of it to get it off. Plastic scrapes were used with the 3m product.. I'm not really sure what my paint base is. It is the factory paint from 1985 though
Mineral spirits won't attack the lacquer paint. Try a small spot on the door frame at the hinges. I know the 3M stuff is pricey, like $35 per quart up here, and way too slow. The trick to the paint stripper is to work fast on one area at a time, like under a minute. In 65F weather, it takes about 5 to 10 seconds to bubble up the vinyl on an area of about one square foot. As soon as it bubbles, you scrape (almost a light stroking) off the stuff, rinse your scraper, and scrape the next row off, rinsing the scraper between each row. Make sure the scraper's edge is clean (sand off any plastic burrs) and hold it with the corners facing away from the body (if the scraper is warped). Remember, that you're going to reinstall the new vinyl, so you only need to concern yourself with minimizing gouges below the woodgrain area, and drips running down below. You could use masking tape and some TYVEK building wrap from a construction site. Paper will absorb, and ordinary plastic might get eaten away with the paint stripper. You'll have to sand off the area anyway with something like 320 grit, going up to maybe 600 grit, to get it all smooth, from the ridges and dents that might be there, and you'll probably have a few rusty stains and pimples to clean up. The heatgun approach could cook the paint below and any bodyfill underneath that, to remove it. I've still got over half of the only 3M remover I bought, and switched to the piant remover because it was just too slow and too expensive. Heck I had me a stool to sit on to do it, because I didn't want to screw up the paint below either. It took me about 4 hours to do the whole car (removal), after diddling with the 3M stuff for an hour. Once you get the feel for the process (apply 1 sq. ft., wait for bubbling, light scraping, rinse, repeat until the adhesive is coming off), you'll see that it cleans up nice. The old adhesive is bone dry, no VOCs (Volatile wada wada), and almost like a cooked varnish. It won't come off until its relubricated. Since we don't know what the compound was, you either sit there with the 3M and rub your fingers to the bone, or you use a mild hydrochloric acid like paint stripper. Sanding it off will cake up your sanding paper and mark the paint. There's nothing else that I know of. If the car was only 3 or four years old, the 3M stuff might work really well, but 25 years old... not likely.
I am actually using the vinyl and decal remover from 3m and what little I have used it it seems ok. I saw the adhesive remover there as well is that what your talking about? I'll try to locate the above stated stripper and see how it works.
Yes. I have used the 3M adhesive remover on many things adhered to a car...BUT...I have never used it in your application. All I know is that it removes all kinds of stickers, emblems, etc from cars without damage. If you have found a system that is working...have patience and you will succeed. I was suggesting the 3M adhesive remover as an alternative when you were having a problem finding a product that would work.
I got the 3M "08984" from a bodyshop supply vendor - Adhesive Remover. Great for cleaning up plastic parts before refinishing them.
the 3m stuff works pretty good... My buddy that owns a 'vinyl decal' company uses...oven cleaner to get old declas off and swears by it! but i wouldnt try paint strippers...thus the 'paint' part to the toolbox
You said you didn't want to hurt the paint under that vinyl....I wouldn't use a stripper if that's the case.
Do NOT use any kind of paint stripper to remove your woodgrain! If you do, you will most certainly be repriming and repainting your whole car! I have never used the oven cleaner thing, but I would certainly give it a shot! Check out Kleen-Strip Aircraft Decal & Adhesive Remover. Google or Bing it. The 3M Adhesive Remover is designed to remove the adhesive left behind after the vinyl woodgrain or decal has been removed. A hairdryer/heatgun is sometimes good for softening up the old vinyl, just don't blister your paint, and be careful not to use it while spraying any combustible product! Any solvent you apply to your paint has the potential to damage it. Always do a test on a hidden area to see if it is ok with your finish! David
I must've worked fast enough, but I did repaint the whole car before replacing the vinyl. I'll defer to my honourable colleagues.