These are my homemade fluting pliars for putting flutes in the ribs I'm going to make. We'll see how they work. I may end up buying a set anyway, but I thought I'd see if I could make it work this way first. After grinding a bit, I think they may work pretty good.
These are made from regular slip-joint pliars.
I used 3/8" bolts with the heads and threads cut off. You could probably get by with smaller rods.
A close-up. As you can see, I'm strictly a seat-of-the pants welder.