No Fear of Failure

"I incorporated the idea of failure explicitly in all the courses I teach. I emphasize that virtually every engineering calculation is ultimately a failure calculation, because without a failure criterion against which to measure the calculated result, it is a meaningless number. "  

                                      ~ Henry Petroski, Duke Professor of Engineering & History

I've never met Dr. Petroski, but for his writings alone he is one of my favorite engineers. (Not my favorite, that spot is reserved in perpetuity, but maybe a close second.) Not least of all because he wrote two wonderful books on the history and design of two of my favorite things in the world: bookshelves and pencils.

He also teaches his Duke engineering students from the writings of Vitruvius and Galileo to underline for them the fact that failure is nothing new, and is something to be embraced and learned from.

All of which leads us from the heights of engineering to my humbling and bumbling attempts at thimbling.

It has occurred to me repeatedly the past couple weeks that it has been a long time since my high school "metal arts" class. The class was woefully misnamed because it was almost wholly devoted to preparing students for careers in the sheet metal and HVAC industries.

That I nevertheless managed to convince the teacher to let me make armor and two swords instead for class credit is almost beside the point. Nerds probably shouldn't be allowed to take metal shop. We're nothing but trouble. (The look on the face of the assistant principal when he caught me walking a broadsword to my locker was priceless, though nothing compared to when he found out I'd only brought it to school to be graded... but that's another story.)

Suffice to say, that the word "dapping" was never uttered in that metal shop and if I'd asked how to make a thimble, I'm not sure I'd have received an answer.  So I wasn't as prepared for some of the silliness that has cropped up between me and the sewing notions as I'd hoped.

The middle American high school just does not adequately prepare you for life in the real world of 1580. We should do something about that.

Here's where we stand on this project:

I've reached a standstill on the thimble making project. Now that I've solved my metal problems, I can adequately troubleshoot things enough to see that my tools are inadequate to the task. Even with a metal face attached, the hardwood dapping block is still not making the grade.

I need a better setup.

One of my failings in planning for this project was acknowledging that, pinners notwithstanding, most of the craftspeople in the 16th century didn't make their own tools. I don't know why I thought making my own dapping tools would be either easy or necessary. I won't be making my own anvil for the blacksmithing section of the show any more than I plan to make my own hammers.

My wife talked to some of her friends at work out in the metal shop and they agreed that the tools were the most likely hook on which to hang blame for my failures. Unfortunately, none of the commercially-available dapping pins and blocks look to be quite right for creating the shape of a period thimble.

So I'm sort of stuck for the moment on this project.

Inspired by a comment Maggie Secara made on the Facebook page, I made this topless thimble (wolf whistle) out of a bit of copper pipe I had lying around. It's a valid stopgap moves things along to the forming and dimpling stages. It's a bit of a cheat, admittedly, but it is the type of thimble I prefer when sewing since I tend to push the needle with the side of my finger instead of the tip.

It isn't pretty, but it is effective.  In the meantime, I'm exploring having a proper dapping block made if I can't find one that will work on the commercial market. (Any leads on that front would be most welcome.)

As I mentioned in the last post, I've also begun working on the Worshipful Company of Coopers and since the weather has turned, will have a parallel project that will keep me inside until it turns again.

More to come, as always!

~Scott

Thimbles: Reloaded

So the consensus opinion here and on the Facebook page is that annealing the brass is the cure for most of my ills.

I really should have thought of that. You may remember when I mentioned that the difference in stiffness between the modern wire and the 16th century wire for pinmaking was the result of work-hardening because of the way that their wire was drawn as it compares to the modern methods of wire drawing.  The folding of the metal in the 16th century style combined with the effort involved in forcing it through the die stiffened the crystalline structure of the metal.

Caple says that in order to wrap the heads, they had to anneal the wire first because the stuff didn't bend.

It's much the same problem with modern brass sheets. Brass, like all sheet metal, is rolled out to the desired thickness in a machine press that compresses the brass between massive wheels. This has the same effect as drawing wire through a period die.

In my sheets of brass, the crystalline structure is aligned and as stiff as it gets. In order to get more play in the metal, I need to excite the molecules by heating the brass and mess up that crystalline structure once more before it will ever suffer the hammer.  It's much the same as doing anything with iron.

The plan for today is to go out and get a thicker piece of brass and then heat it to a dull red heat using a propane torch and work it from there. I have high, cautious, hopes.

Thanks to the Wayne at Leatherworking Reverend, Louise Pass of Woodsholme, and Andrew Williamson for their advice on this.  I'll let you know how it goes!

~Scott

Sidenote: Because it's been so long since I was in high school metal shop, I looked it up online to make sure there wasn't anything I've forgotten.  All of the sites and videos on brass annealing are dedicated to the community of people who reload rifle shells.

I suppose it's the same thing, except my thimble won't explode if I do it wrong...

"So Sybil says to Marjorie, 'Well we didn't want you to come to the quilting bee any way!' and you know how Marjorie gets. She says 'I'll come to that quilting bee if I..."
ka-BOOM!! 

(Fade to black)

(Voiceover) Has this happened to you? Are you the victim of an reloaded thimble? Call Calvin & Hobbes, attorneys at law...

Failure at my fingertips: Thimble making is harder than it looks...

First of all, from one time traveler to another, happy 79th birthday to Tom Baker, better known to some as the 4th Doctor and to many as "That British guy with the hat and the crazy scarf..."

Aside from being my first Doctor, he was also a gifted Shakespearean actor and a member of Sir Laurence Olivier's company. I'd give anything to see him play Lear. Regardless of all that, to me and millions of others, he's the mad man in the blue box.

From the other crazy hat/scarf guy getting himself lost in the time stream, many, many more happy years, sir.
Seriously, folks. If you didn't realize I was geek by now, you just haven't been paying close enough attention.

It's time to talk about finger helmets.

I experienced the first abject failure of the project today. I was attempting to make thimbles based on the Jost Amman illustration of the thimble maker from his Book of Trades. I've reproduced the tools in the etching using hardwood, but the brass keeps tearing out at the bottom of the die.

"Der Fingerhueter", from Das Ständebuch by Jost Amman

Boom. Failure.

Is it that modern brass is softer than what these chaps are using? Do I need a thicker gauge? Should I make the dapping block out of iron instead of hardwood?

A book on the history of trumpet making (of all things) includes an aside on the above image, and some information on the making of thimbles, because it relates to the valves of the trumpet. The author proposes that the brass was 1 mm thick, which is roughly twice the thickness of the brass I've been using.

Ah well. Better luck tomorrow.

In the meantime, it is time to start multi-tasking or I'll never make it.  A least not with out cloning myself and the Calvin & Hobbes trick with the cardboard box didn't work. Might've needed more tigers.

Thankfully, while I was failing miserably at the fine art of thimbling, the books on coopering arrived from England. So, after I gave up on making finger helmets, I spent some time knocking together a shaving horse.

Here's a video for going on with. It's done by Kari Hultman, who is the woodworker behind the fantastic "Village Carpenter" blog. It's an extended interview and demonstration of coopering at Colonial Williamsburg, including the shaving horse I'm working on...

Here's to a more successful day tomorrow!

~Scott

Ramona Vogel: Journeyman Cooper at Colonial Williamsburg from Kari Hultman on Vimeo.