Mating breastplate to backplate issues

[Levi Johnson]

I'm having a terrible time fitting the plackart and breastplate to mate correctly with the back plates, can anyone enlighten me?

[Signo]

To get help, everyone will ask for pictures and a description of the problem.

[RandallMoffett]

I tend to think heat is what helps with mating. Heat the side you move and it will deform the other plates less. Heat makes the fitting much closer. But without more info it'd be hard to say. Perhaps you can drill and clamp or rivet them where you want then work them together?

RPM

[Konstantin the Red]

That's right, pix.

The one thing you've said is you're not satisfied with your results yet, full stop. We'll want to understand where the gaps are and how big, whether you have a ball stake -- or an old bowling ball even -- and what you've been hammering on to try and fix things. Are you working in mild steel? -- it behaves differently from medium-carbon.

Welcome and well come to the Archive, Levi.

[wcallen]

We talked about fit of breast to back at the recent study session.

Unless you are terribly lucky (more lucky than I have ever been), if you want a "correct" fit and you have a breastplate that was made before the backplate..... you will not enjoy the result.

First principles:
The backplate curves around the body a little more than 180 degrees. It sort of cups around you a little bit.
The breastplate curves around the body a little less than 180 degrees.

This allows the breast to slide onto the backplate so that the plates don't actually have to mate perfectly.
The waist lines need to line up.
The bottom of the armholes need to line up.
The curves of the arm holes of the breast and back need to be right so that you end up with something that ends up appearing like an actual curve that connects between the two.

The rest is the actual subtle part of the shaping to make it really work correctly.

You can see some of the usable lines on a backplate here:

http://www.allenantiques.com/A-21.html

Pictures will help see where things are off.

Wade

[Levi Johnson]

Thank you wcallen for that info.

Before I ruin my armour, here are some pictures of the back plates for problem A.

[Levi Johnson]

more pics

[Levi Johnson]

As far as tools, I have a 60lb anvil and a 2" ball with no stake or welder, a 1.5" pipe, about a 5"d log and a bowled out stump. I also have a few different sized ball pien and a 7 or so inch raising hammer. The back plates and breastplate are 18ga mild steel, the front plackart is 16ga mild steel. I don't have any heat abilities at the moment, hoping to build a forge and learn some blacksmithing.

[wcallen]

I am guessing the "problem A" is that the 2 plates on the backplate aren't working together nicely.

Rule one is to copy real stuff, not other people's copies, but here is a breast and back I did that are probably similar to what you are trying to make:

http://www.allenantiques.com/R-23.html

Basically the parts need to be designed to fit together at the right angle. It appears that you have an upper back plate that cups around you, but a lower that goes straight up and down.

The goal with one of these is to have the 2 plates blend together to form a single line that goes out toward the "deep" part and then back in.

I don't know how the parts actually fit you, but I expect that you need a less straight bottom plate. My guess would be that it is a little tall too, but you may be very tall and thin.

I don't know how it fits with the breastplate, or how it fits at your arms and waist, so I really don't have any idea what the "right" fix is.

Wade

[Konstantin the Red]

So could we, then, see some shots in profile of your torso, and then the plates stuck onto you, say first the lower, then add the upper? That may tell us a lot. The situation really looks salvageable.

Backplates tended not so much to perfect imitation of the wearer's back as to sketch it out a bit. Some backplates could look surprisingly like breastplates as they would be well dished out to accommodate the motions of the shoulder blades -- the giveaway would be the lack of arm cutouts scooping from the armholes in the upper half of a breast. Arms don't go backwards far enough to need that.