Removing bad paint

One of the models I started over 10 years ago, is a space shuttle. The paintjob was really bad. The black was applied rather quick and far from nice, and the white touch-ups had gone yellow.

I decided to (try to) remove all the old paint and start over. If it failed, it would be a kit for the scrapheap.
FSM suggested oven cleaner or brake fluid. This sounds drastic, but it has to eat away paint designed to withstand much, so drastic measures must be taken. There's a hobby product for it, called Easy-lift-off, but it's not available here. I decided to try Bref oven-cleaner (extra strong). I sprayed the model with a foamy coat, put it in a plastic bag and let it sit overnight.

The next day, the result is promising. Most of the paint just flows off under running water, some parts need persuasion with a sponge.

The larger part of the bottom is shown below here. The remaining black parts will need another round of oven-cleaner.

After a second application, another nigh soaking and more rubbing with a sponge (the one with a rough - green - and a soft - yellow - side), the result is nice: the black paint is gone, so is the white that turned yellow. The white base-coat however seems 100% unresponsive to the oven-cleaner. It might be Tamiya white from a spraycan, but I do not remember exactly.

This coat of white paint is ok in most places. Where it had formed little drops, I used a sanding stick to get rid of the paint. The rest can stay the way it is. If I wanted to build a perfect shuttle, I'd start over with a new model. As it is now, it's just a matter of trying things out and hoping for the best result possible.