im not sure about the spary on kind, but i got mine in a 1 gallon can from and auto paint supply store and it is some crazy shit....let it sit on the paint for a good 10 min and it will eat it off. i felt my hands starting to burn after about 20 min.....through 2 pairs of rubber gloves! and also wea a mask! that shit burns worse than ammonia if you inhale it!