Page 32 of 76
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:28 am
by Tom B.
Mac wrote:
Tom,
Do you have any more details like that? There seems to be more variation than I would expect. That calls my proposed method of construction into question.
Mac
I just started looking, there are a few more photos of the same sallet in the folders I linked to.
They are under War Gallery, 15th Century.
I was a bit surprised how different the adjacent caps were from each other.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:31 am
by Ghostpig
Jiri Klepac has made some fancy rivets from what looks like a single piece. Maybe he has some thoughts?
viewtopic.php?f=3&t=89885
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:36 am
by Mac
Thanks, Tom!
This image seems to be too big to post here
https://lh4.googleusercontent.com/_RrL6 ... w1389-h641
That rivet up near the visor would be interesting to see up close as well. I think what we can see there is a rivet which has lost its cap and has been pushed up into the helmet. If so, that tells us what the head of the underlying rivet should look like. It also suggests that the caps were tin/lead soldered, rather than brazed... at least in this case.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:41 am
by Tom B.
Mac,
I don't have time to dig up the links (real work to do
)
but here are some Goll #s to look at
1894
1885
1858
1850
1808
1761
1720
1718
1735
2094
1840
4592
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:45 am
by Mac
Ghostpig wrote:Jiri Klepac has made some fancy rivets from what looks like a single piece. Maybe he has some thoughts?
viewtopic.php?f=3&t=89885
Dang! So he has! Good on him, and thank you for pointing this out, GP!
It looks like he has done his fluting from the outside. The tool marks there are quite sharp....
... but on the inside there are not marks other than the ring down at the bottom. I would guess that he used a hollow fluted punch, and finished up by chasing with a chisel from the outside.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:46 am
by Mac
Tom B. wrote:Mac,
I don't have time to dig up the links (real work to do
)
but here are some Goll #s to look at
1894
1885
1858
1850
1808
1761
1720
1718
1735
2094
1840
4592
Thank you, Tom! I will peruse those and report back.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 8:50 am
by Tom B.
Mac wrote:Tom B. wrote:Mac,
I don't have time to dig up the links (real work to do
)
but here are some Goll #s to look at
1894
1885
1858
1850
1808
1761
1720
1718
1735
2094
1840
4592
Thank you, Tom! I will peruse those and report back.
Mac
Also this from page 94 Goll
He seems to think they are not soldered caps.
Goll Page 94 wrote:4.2.1.4 Type-d [ref_ill_riv_d]
Rivets of type-d are probably the most elaborately worked types of all. They are technically based on type-a rivets, but the head is much larger and hemispherical embossed. All examples are made of one piece. Besides simple dome-shaped examples [ref_arm_1727], the head can be decorated by ornamental embossing. Some heads appear like blossoms [ref_arm_1718] [ref_arm_1840] [ref_arm_1858], while at others ridges are spirally winding around the head [ref_arm_1704] [ref_arm_1735] [ref_arm_1837] [ref_arm_1841] [ref_arm_1843] [ref_arm_1894] (probably not all are genuine at [ref_arm_1717] [ref_arm_1720]). This type of rivet has been used merely for the attachment of the lining and the chin-straps of type-VII-helmets. In only one case also a helmet of type-III is equipped with blossom shaped iron rivets of type-d [ref_arm_1383]. A second type-III helmet has similar rivets attached, but they are made of copper alloy [ref_arm_1398]. Unique are the dome-headed examples on [ref_arm_2094]: they are made of a tin or lead alloy. At the breastplate [ref_arm_3734], dome-shaped copper alloy applications that appear like rivet-heads are visible. They are actually separate caps that were sown to the fabric to cover the washers. The copper rivets underneath, together with an iron washer (lost through corrosion) held an exterior fabric cover in place.
Goll's Type D Rivet Diagram
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 9:19 am
by Cet
tin/lead solder should be plenty strong enough for any stress these rivets would see.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 9:44 am
by Mac
I have looked up all of the refs that Tom has posted, and made a Pinterest page of them.
https://www.pinterest.com/macs_shop/dec ... -on-armor/
If anyone knows of more, please tell me, and I'll add them as well.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 9:45 am
by Mac
Cet wrote:tin/lead solder should be plenty strong enough for any stress these rivets would see.
That's probably right, Dave. I guess that's the place to start in any case.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 9:48 am
by Tom B.
There is a possibility that something like the
Portable Antiquities Scheme Database would have some rivets or caps that have become detached.
It is worth a look.
What other databased for objects like this exist, besides the Portable Antiquities Scheme?
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 9:49 am
by Mac
Here's another one that I would like to examine. It looks like the second rivet back from the visor has lost its cap.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:02 am
by Lorccan
Mac wrote:Lorccan,
Of course, nothing we ever do is really authentic. Our materials and techniques are wrong, but we all have to draw our "authenticity lines" somewhere. For me, a solid rivet cast in copper alloy just does not make the cut when the originals were clearly hollow constructs of iron. You might say "but, there you are, thinking about turning your preforms on a modern lathe!" It's true. I was contemplating techniques that they would never have used, but they would have produced a similar product.
In the end, it's the product I'm interested in. I want to make something that looks and acts like the real thing, even if I did not get there the right way. I want the person who wears my armor to have something of a medieval experience, even if I did not have a medieval experience making it.
Mac
That all makes perfect sense - my question arose from a misunderstanding on my part. I knew that the hollow, constructed decorative rivet was a commonplace around the time frame for this harness, but I thought that it existed alongside cast ones. If I understand you now correctly, there are no existing examples of the spiral rivets in question cast in one piece. As such, I can certainly see why you'd reject casting them for this project.
Iron rivets with decorative latten heads always made sense to me as a way to combine strength with decoration, particularly for articulations. For decorative lining rivets, it seems like casting would be easier, and suitably strong - probably the way to go for a less conscientious modern build, but our forebears must have chosen as they did for their own reasons.
I admire Jiri's approach (which, to judge from your sketches, you have also considered), and I wonder how well it could work with a shaped female die, to sharpen things up.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:10 am
by Tom B.
Mac wrote:Thanks, Tom!
This image seems to be too big to post here
https://lh4.googleusercontent.com/_RrL6 ... w1389-h641
That rivet up near the visor would be interesting to see up close as well. I think what we can see there is a rivet which has lost its cap and has been pushed up into the helmet. If so, that tells us what the head of the underlying rivet should look like. It also suggests that the caps were tin/lead soldered, rather than brazed... at least in this case.
Mac
Mac the link does not work for me?
What image are you linking to, I assume it is one of mine?
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:14 am
by Tom B.
Mac wrote:Ghostpig wrote:Jiri Klepac has made some fancy rivets from what looks like a single piece. Maybe he has some thoughts?
viewtopic.php?f=3&t=89885
Dang! So he has! Good on him, and thank you for pointing this out, GP!
Mac
I know Jiri has handled Goll 4592, I wonder if he gained some info from that.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:17 am
by Mac
Tom B. wrote:Mac wrote:Thanks, Tom!
This image seems to be too big to post here
https://lh4.googleusercontent.com/_RrL6 ... w1389-h641
That rivet up near the visor would be interesting to see up close as well. I think what we can see there is a rivet which has lost its cap and has been pushed up into the helmet. If so, that tells us what the head of the underlying rivet should look like. It also suggests that the caps were tin/lead soldered, rather than brazed... at least in this case.
Mac
Mac the link does not work for me?
What image are you linking to, I assume it is one of mine?
Yes. It's one of your RA pics., the 3/4 right back view of IV.427
https://lh4.googleusercontent.com/_RrL6 ... w1389-h641
Strangely enough, the link works OK for me. Computers are a strange sort of magic.
I have tried to pin it here
https://www.pinterest.com/pin/464715255276508898/ but I only get a small image.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:34 am
by Tom B.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 11:14 am
by Mac
Thanks, Tom! I was able to pin up a bigger image from there.
Ah! The Rhodes book. I should have thought of that.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 11:17 am
by Tom B.
Mac wrote:Here's another one that I would like to examine. It looks like the second rivet back from the visor has lost its cap.
Mac
Added a few more photos to my
Sallet Research Picasa Album
Missing Cap Side and top views
Crushed Visor Pivot
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 12:17 pm
by Mac
Has this rivet lost its head? or is is a replacement?
A look inside the helmet is inconclusive. I think I see a projecting rivet shank, but it might be wishful thinking.
Here's another rivet on the same helmet that I would like to have a closer look at.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 12:27 pm
by Mac
This is a nice blow up that Tom has made. I wish we has this from a couple of angles.
This pic of the visor pivot is pretty straightforward, though. I think we can be pretty sure that where was no internal step on the shank like Barbanegra postulated. This is the sort of armor failure that can ruin your day. I suspect that it's easier to do this to a pivot than to a lining rivet because of the relative thicknesses of the shanks. The thinner lining rivets are more likely to get cocked in their holes and bend before they can be pushed very far into the helmet.
Thinking about it some more, though, I wonder if that's a valid conclusion.... I think it's likely enough to be true of modern straight sided holes, but the period ones are going to be wider on the outsides, and that might well make the rivets less likely to cock and bend. Hmmmm.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 1:00 pm
by Tom B.
Mac wrote:Has this rivet lost its head? or is is a replacement?
A look inside the helmet is inconclusive. I think I see a projecting rivet shank, but it might be wishful thinking.
Here's another rivet on the same helmet that I would like to have a closer look at.
Mac
Added details to the same Picasa folder,
Sallet Research (file names hopefully indicate vie angle and helmet section of the details)
This is Goll# 1727
1727 Left side - Side View
1727 left side - back 3/4 view
1727 LEFT side - Inside view
1727 right side - Side view
1727 right side - 3:4 Front view
1727 right side - Inside view
1727 back right side of ctr - Inside view (this is just to show the inside washer and peened rivet of some intact decorative rivets)
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 1:32 pm
by Jason Grimes
It's starting to look like they had many different ways to do the same thing. Exactly like Mac said before, it's not how you get there as long as the end result is good. I'm starting to lean towards that last method as the easiest and safest. I wouldn't put a step on it either, just draw down the rivet shank until it fits the hole with enough to peen over. Cut the shank off so it fits in the cap, then solder it in.
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 2:43 pm
by Mac
I'm still not sure exactly what to make of this. The color suggests brass, so maybe it's what's left of the brazing for a cap. There are conditions under which high tin allows of lead will turn this color as well. It has lead to some pewter castings being described as copper alloy or even gilt.
This, on the other hand tells us quite a bit. Do you see how the peened end of this rivet shank has split? This is typical of wrought iron rivets. It seems pretty unlikely that the other end of this rivet could have been successfully forged into the dome it currently possesses. I count this as very strong evidence that the domes are soldered onto, rather than forged in one with, the shanks.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 3:13 pm
by Zanetto
Mac,
So far I have a spiral rivet cap punch filed to shape, hardened and tempered:
http://i186.photobucket.com/albums/x171 ... zqoalm.jpg
I made some test caps from .015" brass and dapped them into lead. I realized that the caps are not tall enough so
I will have to start with a bigger disc. They ended up having to be pried out of the lead. Also the sharp flutes on the punch sheared through the brass:
http://i186.photobucket.com/albums/x171 ... lqw2ea.jpg
I then made up a bottom block that fits into the hardy hole of my colonial anvil. I hogged out some material with a 5/16" drill bit, heated the whole thing up and drove my punch into the hot steel to create the negative die. I am waiting on a set of dapping punches to test out the steel die. I will report back (with photos) after I am able make some test caps out of .032" 1050 discs.
Rob
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 3:21 pm
by Johann ColdIron
Zanetto wrote:Mac,
So far I have a spiral rivet cap punch filed to shape, hardened and tempered:
http://i186.photobucket.com/albums/x171 ... zqoalm.jpg
I made some test caps from .015" brass and dapped them into lead. I realized that the caps are not tall enough so
I will have to start with a bigger disc. They ended up having to be pried out of the lead. Also the sharp flutes on the punch sheared through the brass:
http://i186.photobucket.com/albums/x171 ... lqw2ea.jpg
I then made up a bottom block that fits into the hardy hole of my colonial anvil. I hogged out some material with a 5/16" drill bit, heated the whole thing up and drove my punch into the hot steel to create the negative die. I am waiting on a set of dapping punches to test out the steel die. I will report back (with photos) after I am able make some test caps out of .032" 1050 discs.
Rob
Neat work Rob! The world needs more capped rivets!
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 4:13 pm
by Mac
Splendid, Rob!
When I made my tools for the Jello-Mold caps, I did basically the same thing. I ended up grinding out a lot of material to accommodate the thickness of the cap. I recommend making up a good cap in steel, using the lead (or better yet, tin), and than take the punch with the cap still in place and use that to finish out the die. That will make your die big enough for the cap thickness. This is what I wish I had done, and swore that I would do next time.
I also rotated the punch to all six (?) orientations to average out the inaccuracies. That way I don't have to keep track of which gadroon is which. I just give the punch a whack and a turn till I've used all the orientations.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 5:23 pm
by Zanetto
Mac,
Good idea about rotating the punch. I made punch marks so I could locate the the male punch in relation to the female die. I will try your idea in one of my test blocks after I forge them up.
Here is a picture of my block with the test pieces in .032" steel. I think I lost some pictures along the way. i'll take some more tomorrrow:
http://i186.photobucket.com/albums/x171 ... dv2vdi.jpg
http://i186.photobucket.com/albums/x171 ... fqdxy6.jpg
This experiment has shown that I definitely need die clearance for this method to work. I will do this with the mark II bottom block.
Rob
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 7:00 pm
by Mac
That looks nice, Rob!
Here are the tools I made about ten years age for the Jello-mold rivet caps. There were some spares and some blanks in the drawer with the tools, so I put them in the pic as well. I used them as "washers" and peened the rivets up on the outside, but they could just as easily be soldered on to the rivet heads.
Just for the photo shoot, I put one of the spare domes in teh header and gave it a few whacks.
And, not surprisingly, it still works.
The die has a tang to fit the hardy hole of my smaller anvil.
I guess I will use some of these to experiment with, and see if I can come up with a soldering procedure.
Mac
Re: Dusting off the cobwebs
Posted: Tue May 05, 2015 10:36 pm
by Mac
Here's the smoking gun.
Object S-30 from Churburg shows several examples where brass caps have come away revealing the impression of the cap in what is almost certainly tin/lead solder.
This detail shows where the solder has partly pulled away from the iron rivet head,revealing that the underlying head has been shaped up to more or less match the inside of the cap. This surface preparation would have minimized the thickness of the solder lines and improved the strength of the joint. In the case of the lower rivet, it's clear that the solder did not wet properly to either the rivet or the cap.
Mac
Re: Dusting off the cobwebs
Posted: Wed May 06, 2015 1:15 am
by Jason Grimes
I found some more examples:
Late 15th century Spanish helmet with one of the caps missing, or maybe the top of the cap has been taken off?
- Hispano Mauresque Sallet.jpg (93.05 KiB) Viewed 422 times
This next one is fragmentary sallet that looks to have the same type of rivets that Jiri is making?
- DSC07942_sized.JPG (52.04 KiB) Viewed 422 times
- DSC07981_sized.JPG (72.83 KiB) Viewed 422 times
Re: Dusting off the cobwebs
Posted: Wed May 06, 2015 1:17 am
by Jason Grimes
Another image of the inside:
- DSC07986_sized.JPG (92.36 KiB) Viewed 422 times
I had to severely resize these and I have several more images of the helmet so if you want better resolution or the other images let me know and I can email them to you.
Re: Dusting off the cobwebs
Posted: Wed May 06, 2015 3:48 am
by Zanetto
Mac,
So Churburg S-30 shows us that at least with copper alloy spiral caps, they are soldered onto an iron rivet. The rivet also has a smaller spiral shaped head to provide a matching surface for soldering on the cap.
Do you think the iron spiral caps are soldered onto iron shanks or made in one piece like Jiri is doing?
Rob
Re: Dusting off the cobwebs
Posted: Wed May 06, 2015 7:40 am
by Mac
Rob,
It's true. My smoking gun example only proves that they soldered bras caps onto iron shanks. It does not prove that they soldered iron caps onto iron shanks.
Jiri K has demonstrated that you can make fluted, dome headed rivets all in one, but there are two thing that make me think the soldered on caps are probably the norm. The first is the nature of wrought iron. I think it would be difficult or impossible to treat wrought iron that way without it splitting. We have seen one example (Goll 1727) where we can see that the inside end of the shank splits readily, like typical wrought iron rivets do. In that case it seems almost certain the the dome is separate.
The other thing that makes me think the spiral domes (at least) are soldered on is how the fluting continues across the center of the dome. That's easy if the dome is separate, but next to impossible is it's formed up out of one piece.
Although we can not rule out one piece constitutions, I thing we can conclude that soldered-on domes are typical and usual.
Mac
Re: Dusting off the cobwebs
Posted: Wed May 06, 2015 8:02 am
by Tom B.
Mac wrote:Rob,
It's true. My smoking gun example only proves that they soldered bras caps onto iron shanks. It does not prove that they soldered iron caps onto iron shanks.
Jiri K has demonstrated that you can make fluted, dome headed rivets all in one, but there are two thing that make me think the soldered on caps are probably the norm. The first is the nature of wrought iron. I think it would be difficult or impossible to treat wrought iron that way without it splitting. We have seen one example (Goll 1727) where we can see that the inside end of the shank splits readily, like typical wrought iron rivets do. In that case it seems almost certain the the dome is separate.
The other thing that makes me think the spiral domes (at least) are soldered on is how the fluting continues across the center of the dome. That's easy if the dome is separate, but next to impossible is it's formed up out of one piece.
Although we can not rule out one piece constitutions, I thing we can conclude that soldered-on domes are typical and usual.
Mac
All of that combined with these images from Goll 1850 (looks like a rivet head shaped for a soldered on cap), make a pretty good case.
