Round viking age shields

[Dabbsterinn]

Hello everone, earlier this year a guy messaged me about getting a viking age re-enactment group started/revived in close to where I live so of course I jumped in on that and got more active in the smithy than I have been for the past few years. 

That resulted in these 5 shields that I've been working on for the past few days.

I hand forged those bosses, made a jig for cutting the circle consistently, a new dishing hammer and a new jig for dishing (will update with pictures of those when I finally remember taking them)

tonight I finished riveting the bosses on and nailing the rawhide rim on 3 of them and on the other two I'll put 3-4 layers of duct tape for research purposes since these are just for the practice swordfights authenticity isn't as important (and I'll take any chance I get to avoid handling wet rawhide, that texture drives me up the wall)

9mm-3/8in plywood, 59.5cm in diameter

2.5mm mild steel plate 250mm/11 inches in diameter before dishing

rivets are just 2 inch nails except for the top right one, I used some hand forged nails for that one since it's a boss I made close to 10 years ago and had drilled the holes way too big

[George N. M.]

will they have a metal or leather rim?  Is the grip behind the boss?  What thickness of plywood are you using?

GNM

[Dabbsterinn]

the rawhide, sourced from dog bones, is what we normally use for the rim but if the duct tape experiment doesn't work I have a good collection of sheep leather scraps I might cover the rim with, I also need to go over the nails again now that the rawhide has dried out and blunt or bend some of the points that are sticking out 

there's a rather beefy wooden grip behind the boss and I cut out the center of the shield to fit the hand inside the boss.

I forgot to bring my jigsaw with me when I went to cut the holes so I had to improvise with a 12mm drill bit and a straight die grinder and I think it came out pretty well, I bolted all 8 plates I was working on together and cut the center holes in all of them in one go

broke out my hand-loading calipers for the thickness question since they're easier to photograph

[Dabbsterinn]

Here's the pictures as promised, the hammer is approx 600g/a bit over a pound and the face is about half way between a ball peen and a rounding hammer in the roundness factor. I used mild steel for this one since it's a test piece, when this one wears out I'll make it again with some proper steel.

 

  

Here's the dishing ring, I really wished for a cone mandrel when bending that but there's really no need for a perfect circle since all it does is support the edges and has free space underneath, the thing I welded the ring onto was a failed experiement for a jig to chisel the center of a long piece of 16mm(5/8ths) square for a pineapple twist

this is my cutting template, 27cm or so in diameter with two tabs for clamping to the plate and the plasma torch rides on the inside of the ring. there was my second wish for a cone mandrel, maybe on the third wish I'll look into getting some heavy plates and searching for a mate with a hefty slip roller in the shed 

[George N. M.]

I like that hammer a lot.  Are you using a swage block to raise the bosses or a block of wood?  And are you doing them hot or cold?

Thanks.

GNM

[Dabbsterinn]

Thank you! I'll be making several more in a similar style when I get into more sheet metal work
I'm actually dishing them hot in that bigger circle that's in my anvil, that thing takes up way less space than a swage block or a piece of wood large enough for the shield bosses. the downside is that I have no definitive guide for the shape other than my eyes but they still come out pretty good, I can get most of the unevenness out by hammering them cold on the anvil. 
should I ever come across a big ball bearing or some other dome shaped steel I might try making a ball stake and raising them and see how that goes. 

[Frosty]

I cut circles, usually with a torch or reciprocating saw by placing an old computer magnet over the center and use a Compass that clamps to the torch. I made the compass with labware clamps and 1/4" round stock. In a pinch wire works fine.

If you check with a company that sells wire rope they will carry or be able to order "headache balls" of various weights. These are the balls clamped to crane cables above the hook to prevent the cable from free wheeling on the drum.

I have one I planned on making into a mushroom stake but discovered it worked fine laying on a small log. Back in the day I used it to planish the hammer marks out of SCA fighter helms until I gave up on ever getting paid for armor. I shined up half of the 7" ball with sanding disks and used various soft mallets. Didn't use it much, I stopped making SCA armor, nobody wanted to pay.

Frosty The Lucky. 

[Dabbsterinn]

I'm not quite following the compass design you described there, do you have a picture or a drawing that might make it clearer to me? I'm mostly wondering how the round stock attaches to the magnet. I'm also guessing it's a beam type compass rather than a V shaped one since I imagine the legs would get in the way when moving the torch around.

great idea with the headache balls, there are at least 3 net makers nearby and 1 store that sells all kinds of lifting equipment so I'll be surprised if I can't find one and even if I can't I think I've seen some steel net floats that should be able to do the same job, there's even a plan C which would be to take the top off of one of the empty TIG gas tanks since we're already planning on sacrificing it to get the curved bottom piece for dishing. might even use the body of it for a slack tub or a gas forge
I reckon a diagram like those for meat cuts but with a gas bottle might put a smile on many faces here and inspire some ideas perhaps.
 

 

[Frosty]

Yes, it's a beam compass, one clamp holds a point that sockets into the center of the magnet or a deep center punch mark. I'll have to dig it out and take a pic. I shut the shop down for this winter, snow carried the stack for the barrel stove off and I'm not getting up on the steel roof when it's covered in snow and ice.

I made it from lab stand clamps so aluminum rod would probably fit work better without being too heavy. The torch clamps on and doesn't have a pivot so you have to walk it around. What it does do that commercial circle cutters don't is let you tip the torch in or out of the circle. This lets you make angled cuts so you don't have to grind weld relief for good or full penetration welds. I cut more of an angle for stand bases so you're not so likely to trip on an edge. 

An early mistake was making the torch clamp slide for radius adjustment, unfortunately it meant you could have 30-40 cm. of rod sticking out past the torch and hitting things, Sooo I put another sliding clamp on the center point so extra rod is extending over the center of the cut rather than sticking out making a larger footprint in the shop. 

It doesn't have a stand off wheel to keep the torch tip at the correct height of the work, I eyeball that and maintain standoff by hand. Trying to use a wheel or my favorite 1/4" rod bent like a hair pin just didn't work well with the torch angled.

It also clamps onto my reciprocating saws with a little imaginative modification. 

I use a guide for torch cuts any time it's possible, it saves a lot of grinder cleanup time. Sometimes all the clean up I need to do is knock the bit of slag off the back side of the torch cuts with a chipping hammer though almost anything works.

Frosty The Lucky.