I had one delaminate while using it (3"), I think I had way too much product on it and the glue let go (similar to LC Hydrotech if you use them while wet). Let the place where I bought it know and they sent me a new one. So possibly that was the issue. They do get quite warm while in use. Haven't had a failure since (and I've revised my priming technique to ensure I don't oversaturate the pad)