question about helm top

[serferdude]

I posted this over on another forum and a member suggested I try this forum. I am working on a great helm and am having difficulty with the top. When trying to fold the edge over the top plates it crinkles and ends up looking like a giant soda-bottle cap. Am I attempting to do the impossible by making one circumference into a smaller one or am I just doing something wrong? I have noticed on modern repros they have spaces cut out (presumably to eliminate the stresses) and the remaining steel is folded down into a tab which then receives the rivet. The helm on the effigy I am basing this on does appear to have the crinkles but if so they are very even and smallish, something I might not be able to reproduce. Or it could just as well be the method used by the stonecarver/artist. Also, I'm planning to paint the helm. Any suggestions?

[losthelm]

slow down your trying to move to much metal at one pass.
depending on the thickness it should take about 5 passes or so.
When you see a pucker address the problem the larger it is the harder to fix.

[Milan H]

Many, smaller passes is better than one or two big ones. You are literally trying to compress the metal, which is why it puckers. Hammer them out when the pucker is small and manageable.

It would probably be magnitudes easier to do with the metal at red heat as well, if you have the equipment to do this efficiently.

What kind of tools are you using/have available?

Can you post some pics of your helmet and the effigy you are basing it on? we may have more insight in the construction to help you out.

Cheers!

[Konstantin the Red]

If he's bottlecapping, likely he's working it cold.

Serferdude, welcome and well come to the Archive.

Well, with our site's penchant for following historical models a lot, as closely as our varied abilities allow, let us inquire if you're trying to reproduce a particular historical example -- or blend two or three of them for an "inspired-by" kind of work.

Are you going for an exterior-fit top cap or an interiorly fitted one as in the later types of greats?

We tend to go "meh" at the tabbed tops. They are very difficult to do neatly. Something that in an engineering sense is between a tabbed top cap and a riveting flange that is solid all the way around is the teardrop top, that fits into a greathelm that has a center-front crease to it. A notch at the point of the teardrop relieves some of the struggle to get that flange down and mates up neatly with a center front crease. It's also perfectly fine with an interior-fit top cap.

A valuable thing to do if you possibly can is to dish the top cap some. This accomplishes some of the downward bending you want, leaving less to do at the riveting flange that makes up the edge. It also makes the helm's lines more graceful, the helm itself less of a 'mace landing pad,' and fits the helm more closely to the curvatures of your skull. Early to mid thirteenth century helms were very cylindrical and bucketish, making no attempt to do this, but about the middle of the thirteenth they were starting to round off the tops.

Do as Lostie and Milan said: don't hurry, do a bunch of laps around bending the flange in little by little, persuading the metal rather than bashing at it hard. Ripples, when they appear, go onto the flat surface of your anvil (or substitute), and you sort of bounce your hammer strokes towards the sides as you hammer the ripples flat again, blending them into the proper curvature of the edge rather than the sharper bend of a ripple. You are trying to coax the metal to flow together.

This technique is indeed making your edge circumference smaller, so that the piece must bend down.

Paint: prime all surfaces with spraypaint primer. Rust-Oleum is the favorite, and for good reason. Paint both inside and outside of the helm and your rust problems will be long delayed.

The very modern production method is likely to be fabbing up the top cap out of 12ga and a flange made of suitably bent 3/4" bar-stock/flat-stock, then grinding the weld absolutely smooth. And the sheet metal really must be dished a bit or even pent-roof creased fore and aft -- this feature is usually associated with interior-fit top caps.

[Sean Powell]

Hello and Welcome to the archive.

You've already noticed that the cheep/quick (sloppy imho) solution is to use a tap-top. Fording a consistant lip will give you a prettier seam but as you have noticed it IS more difficult. Think about the material that is cut away in a tap-top. The material that is removed in a tap top to reduce stress will have to be MOVED in a continuous seam. The easy way to move is to buckle like a soda cap. The better way to move to to stretch it like a soda CAN. Ever notice that a soda can has no lower seam like at the top? A soda can is stretched just like your helm top and starts as a disk of aluminum maybe 5" in diameter. Millions of soda cans out there say you can do this so don't worry, you will, it will just take practice.

Do you have a section of pipe, maybe 4-6 inches in diameter? If you work the helm the way you have been you will start to see wrinkles forming. Lay the helm top on the edge of the pipe with the wrinkle over the side and only a hairs width from touching the wall. Now hammer down at an angle with a cross-peen hammer. You want the metal to touch the anvil but you arn't trying to pinch the metal hard, just encourage it to go in the right direction. You want to angle the hammer strikes so the 'pull' the wrinkled metal away from the center. By pulling the metal down you will smooth out the wrinkles and get more fold at the same time.

I hope that this helps. Not certain if I explained it well without pictures.

Sean

[Pitbull Armory]

Hi there Serferdude, Welcome to the AA. Thank you Konstantin and Sean I think your advice is dead on. Another option is to weld the flange on if you cant manage bending it. Good luck and post pics.

Take care

Pitbull

[Konstantin the Red]

. . . to weld the flange on if you can't manage bending it. Good luck and post pics.

The very modern production method is likely to be fabbing up the top cap out of 12ga and a flange made of suitably bent 3/4" bar-stock/flat-stock, then grinding the weld absolutely smooth.

Think I had that covered there, boss. (We ain't got no stick-poke smiley on this board.) By fabbing up I mean "fabricating." If it's fabulous too, kudos to you.

The above was Kirby D. Wise's helm-top recipe. I imagine he chose 12 ga sheet was in part for convenience in welding flange to top cap. Nice deep metal that was harder to blow through with your torch.

[Konstantin the Red]

While you're working this out, there's also another very craftsmanlike thing to do that shows up primarily in later greathelms. The two upper plates may be bent inwards a little at their top edges to meet the riveting flange of the top cap, allowing for a more moderate bending of that top cap. Doing this neatly does take some care, since your bend line should not meander at all or this kind of fitting will be difficult; mark out and closely follow a neat bend line. Look at the fit of the top cap on either of the known Pembridge-pattern greathelms for good examples. So similar are these helms, right down to being maybe an ounce or two different in weight, that it's likely these helms came from the same shop.

[edited 'cos I malapropped]

[Pitbull Armory]

Howdy Konstantin, Oops yes I see now where you did mention welding the rim on, But I dont know what a stick poke smiley is. or means. Konsantin do you make armor? Your advice to people idicates that you do, If so, is there pics of it anywhere I want to check it out?

Take care

Pitbull

[Konstantin the Red]

Haven't made any in quite a while, so alas I am presently more a talker than a doer. That confessed, the sort of thing I say is the sort of thing I'd try.

Boards vary in the elaboration of their smileys... the general social-networking boards tend to the more elaborate ones, certainly more elaborate than what we have here. :Stickpoke: is an animated one, has two smiley discs and one of them is prodding the other one with a stick, poke poke, poke poke. I'm sure the implication is easy enough to read -- will he just fall dead or will a swarm of hornets come out? Or what? Stay tuned... for another exciting adventure in animated Smileydom! Brought to you by my halidom...! If I could do any poetry but magnetic poetry I'd be dangerous, I would...

[Pitbull Armory]

Hiya, Ok thank you, I get the smiley thing now. Your comments on armor seem to be dead on whether you make it at this time or not.

Thank you

Pitbull

[sha-ul]

Haven't made any in quite a while, so alas I am presently more a talker than a doer. That confessed, the sort of thing I say is the sort of thing I'd try.

Boards vary in the elaboration of their smileys... the general social-networking boards tend to the more elaborate ones, certainly more elaborate than what we have here. :Stickpoke: is an animated one, has two smiley discs and one of them is prodding the other one with a stick, poke poke, poke poke. I'm sure the implication is easy enough to read -- will he just fall dead or will a swarm of hornets come out? Or what? Stay tuned... for another exciting adventure in animated Smileydom! Brought to you by my halidom...! If I could do any poetry but magnetic poetry I'd be dangerous, I would...

something like this?

[Konstantin the Red]

It's one possible outcome.

The "beat a dead horse" smiley is another favorite.

The Flying Spaghetti Monster, well, that's merely cryptic.

[sha-ul]

I've shared the link to my smiley stash several times, but some time I just feel like I'm




http://s155.photobucket.com/albums/s294 ... ?start=all

btw if you find any good ones let me know so I can share them.

[Konstantin the Red]

Hee. I have absolutely no idea how to upload an image, particularly an animated grab, from such a thesaurus.

[schreiber]

Hi and welcome, serferdude.
Basically what you're trying to do is raising, which is an advanced technique.
If you want to get it done without raising, and want to use the tab method, then I'd suggest thinking about going with a later style helm, where you could put the tabs on the INSIDE of the skull and basically cover up that you did it that way.

I have never been able to do it cold. I have heat, and every time I try to do something like this I start cold, come to the conclusion that it's going to get mangled, and then add heat to make it work.

If you don't have an O/A torch then realize that a propane plumbing torch will do the trick, but MAPP will do the trick faster, though. Both are snail's pace compared to even a sucky O/A.

However when doing something like this I like to work locally: I don't like using venturi burners or open forges, since they heat a large area (slowly!), and if you're raising it's easier IMO to work with a small area. For turning edges like this, I find that a really small area works best. If you can heat up an area the size of a quarter to red-orange, and chase that for about 2-3", then you're in serious business.

[sha-ul]

Hee. I have absolutely no idea how to upload an image, particularly an animated grab, from such a thesaurus.

if you wish to use some from my photobucket, hover over the image, a box with 4 lines will appear,for here you want to copy& paste the bottom box, it is already formatted for these fora. then paste into the appropriate thread.