I fixed holes in the bottom of a boat with the product. I learned about this product from the Aluminum-Weld youtube channel. I do some soldering on copper pipe and welding at basic level. This product worked great. I did cover the welds with an epoxy filler just so it would look nice after painting. Someone who is better at brazing/welding/grinding will probably be able to get a smooth surface just with the rods. The boat is a family heirloom. I am glad to get it back in the water and fish with my kids.