I must admit that I don't really understand planishing, or what it does. I did see in the videos, using a hammer and dolly to flatten the welds. I assume that this is planishing. I did try this while doing the welding, although I didn't really know what I was doing. I gave it up because there was no way to get to the backside of the welds with a dolly, or anything else, so the steel just sprang when I tapped it. There's nothing on the backside of the metal in that area to support it, so it's pretty springy. I did grind down the welds, and while it did make it look pretty nice, the ridge or pucker at the seam was still there.
