Learning from the mistake we made with Fast Etch, we followed the instructions on the CLR bottle to the letter. They say to rinse treated surfaces with cold water within two minutes of application, and that’s what we did. Unfortunately, they didn’t have autobody work in mind, because the car instantly flash-rusted after being rinsed with water, and we had to reapply the CLR to remove it. Can you sense our frustration? This time, we worked panel by panel, wiping the second coating of CLR with lacquer thinner before it had a chance to dry.