Shield boss

[Cassius Chaerea]

I am making a boss for my scutum and seem to have hit a rut. I have limited metal tools, but have managed to get a bowl shape started. I used a wood mold, then it broke. Then I used a hole in the ground. I would like to know the best way to get the bowl smoother and get those nasty bumps out. I also am having troubles with the edge of the bowl,where it meets the flat metal. Any help would be appreciated.

Cassius

[GaiusManliusMagnus]

I've done about 20 of these, with pretty good success though I'm no master smith.

Getting the lumps out takes two things. Practice and Planishing. Practice getting the blows close together and even. This will reduce the deformation by a large degree. More practice, less deformation. For the final smoothing, Planishin is a process using a flat hammer on the outside to pinch the metal against a super smooth stake, usually mushroom shaped. This can be faked with a trailer hitch ball that has had the load stamp ground off and the edges eased.

The edges need to be formed against an edge of some kind. I ground a small radius (c3/32") on one edge of my anvil to do this, but nearly any hard edge would work. Hold the umbo, bowl down, against the edge with the flange over the top of the anvil and sink the inside of the bowl towards the anvil edge, working by turning the bowl about its center axis so that the impacted edge is being pinched between the hammer and the edge. I usually work this with the bowl on the far side of the anvil so that the blows are toward me. If the flange is already deformed, flatten it on the anvil top as you rotate the bowl around.

Anyway, hope this helps.