I filled some gaps with cement to prevent water from passing through and then I painted it with the spray. It turned out really well, it adhered very well to the cement. Very good adhesion, as they say, and no water passes through at all (the cement is sloped, of course)

I used it on a Fiat Punto as well as on Hyundai and Mercedes vehicles, 8 and 20 years old, which over the years, with mud and water with salts, later developed traces of rust. 2-3 cans are more than enough when we want to apply many layers of paint on 1 vehicle.
The process is simple: it must be clean underneath, any sign of oil we remove with gasoline, and we apply it at first just enough to lightly cover the surface, and then after 5-10 minutes we spray again.
As always, safety measures are important and most importantly we should wear a mask-gloves and glasses with a long-sleeved shirt (if we have a light cap or a baseball cap worn backwards), otherwise you have to clean everything with gasoline (or sodium) and you always have to shake it very well for 1 minute and then spray.

If it does not spray well because of the heat, clean a little the nozzle that sprays with a little gasoline or sodium (which is sold in all paint shops)

Very good, I applied the sealer that I use for my boat, it bonded well with the metal and created a very good surface that doesn't rust at all now. If you have something worth protecting with this, I recommend it! Oh, obviously keep in mind, if you spray it on asphalt, it won't have the same aesthetic surface and car color, as my brother told me, haha