I bought the product primarily to repair the bottom of an aluminum boat and it performed exactly as promised. No complaints! But before doing that, however, as a test, I tried joining two 1/8 inch plates together perpendicularly (following the printed instructions) and was disappointed when they broke apart will very little effort. I called the 800 number, explained what I'd done (and how) and got some tips on how to improve the "weld". I followed the advice and got a far superior result, so technique has a lot to do with it. The fact that the product works and that they are there to help has me sold on the product and the company.