Late Anglo-Saxon Disk-Brooches. Part 2 (Enamel)

This is Part 2 of my series of blog posts about my Late Anglo-Saxon Disk-Brooch Project. In this part of the series I talk about my reasons for experimenting with Flameworking glass rods and turning them into a fine powder which can be used as Enamel.


Part 1 is a general history of the disk-brooches that my research and fabrication project centers around.

I purchased several end bits of Lampworking glass rods, which are used in bead making, in several of the colors used in Anglo-Saxon glass beads, in order to make my own vitreous enamel. Full, new rods aren't necessary since I will be crushing them. I also like the idea of recycling in this way, something I'm certain was done in period.

I only needed the end bits since I will using the technique discussed by Theophilus in, "On Divers Arts" to make my own vitreous enamel. Using thermal shock I will shatter them into smaller pieces, then crush them with a pestle with some distilled water, to reduce the dust in the air and as a bit of a lubrication, until they are finely ground. I will be wearing a good quality 3M respirator for fine particles and eye protection.

The bottom, horizontal rod is Marshmallow white which is the only full rod that I purchased that day. I have a couple dozen rods I purchased at previous EK Metalsmiths' Symposiums for making Viking Age beads, some of those rods might be the needed colors.

The dark looking rods between the white and turquoise, as well in the second picture, is actually a transparent, dark blue which is lovely.

I've been researching the sources for Anglo-Saxons enamel and so far it seems to be the same glass used for Anglo-Saxon beads. I will be writing a separate Blog entry about this section of my research.

I will also be using Thompson's lead-free enamels on several of the Anglo-Saxon brooches, though I will not mix these  on the same piece with the enamel I will make. The glass rods have a CoE* of 104 and the Thompson lead-free enamels have different CoEs depending on which series they are from.

* CoE = "Coeffecient of Expansion"

Many thanks to the discussion and helpful information from Mistress Elysabeth Underhill, O.L. during EK Metalsmiths' Symposium 17 (MSS) this month. She was generous with her time to help pull out these color rods from a large container of them to aid me in my project. I greatly appreciate it.


Links:
Late Anglo-Saxon Disk-Brooches, Part 1

My Facebook Photo Album of this project

Cloisonné, Vitreous Enameled Award Medallion Photo Tutorial

I made myself this Cloisonne enameled medallion last week at Pennsic during War week in my camp, S.O.R.D..

This is my Order of the Maunche medallion which is an Award of High Merit for Arts and Science in the East Kingdom of the Society for Creative Anachronism.


See: Getting Started: Vitreous Enameling Pennsic 2018

Late Anglo-Saxon Disk-Brooches. Part 1

This is Part 1 of my series of blog posts about my Late Anglo-Saxon Disk-Brooch Project. In this part of the series I talk about their general history as part of my research and fabrication project.

The Anglo-Saxons inhabited Great Britain from the 5th to the 11th centuries, from the end of Roman Britain, about 450, until the Norman conquest in 1066. They made a variety of disk brooches which included both inlayed garnet and glass Cloisonné pieces as well as Cloisonné enamel brooches. During the late 10th and 11th centuries the Anglo-Saxons made a variety of rarely studied Copper-gilt disk-brooches with Cloisonné enamel centerpieces, these fell into two categories:

- the Saunderton type, with several lobes and Cloisonné enamel centerpiece

- the Colchester type, with a flange and Cloisonné enamel centerpiece

The Cloisonné enamel centerpieces have a wide variety of designs, the majority of which are geometric. The brooches are under an inch in width (< 25 mm) and usually made of a Copper alloy or Copper, most were Mercury Gilded (a.k.a. Fire-Gilding), though several have been found without any traces of gilding.

Over the following year I will be continuing my research on these rarely studied disk-brooches and will make a variety of ungilded pieces. I will be using a Copper alloy, Bronze* a.k.a. Grade "C" Phosphor Bronze (CDA#521) [8% Tin (Sn) and 92% Copper (Cu)] and Copper in sheet form, and making my own Cloisonné 'wire' from sheet.

* The Anglo-Saxons used Bronze that was on average about 10% Tin (Sn) and 90% Copper (Cu). Tin was available in Great Britain through mining, but Zinc (Zn) needed to be imported, this means that they rarely used any of the Brasses which are a Copper Alloy of Copper (Cu) and Zinc (Zn).

My enameling will be done using an enameling kiln and mainly Thompson lead free enamels for both the centerpieces and the cabochons set in the lobes. I will also be fabricating a piece using the Flameworking glass rods that I will process into powder to make my own enamel, see Part 2 , Part 3, and Part 4 of this blog series for my process and results.


My Facebook Photo Album of this project

Hot Work Workstation PDF

I

I spent some time researching and putting together a resource PDF sheet for the fb metalsmithing group I run, Gaeira's Bench and is located in the File section of the group page. I found a variety of tutorials, etc. for hot work: soldering, casting, enameling, 

workstations, etc. that can be easily constructed out of bricks, kiln bricks, steel sheets, steel rods, and/or compressed charcoal blocks, etc. The collage includes the URLs next to each set of images and I added them to the comments section as well for easy access.

Links:

https://www.facebook.com/groups/GaeirasBench/

https://www.facebook.com/groups/GaeirasBench/permalink/1091437530995621/

Riveting or...drill, hammer, repeat. Part 1

This is Part 1 of my series of blog posts about the different types of drilled holes and Rivet styles. It about my two days of experimentation and practice with riveting; I worked on three different methods of using annealed, solid Brass Escutcheon pins as well as learning to use a Nail Set tool instead of a ball peen or riveting hammer as I was use to. 

For a couple of afternoons this week I practicing several different riveting techniques. I used 18 gauge, solid brass escutcheon pins as "rivets" with two 26 gauge sheets of copper. For all of the techniques I either used a 2/32nds Inch nail set (when striking the 18ga wire) or a 3/32nd Inch nail set (when striking the dome of the 18 gauge Escutcheon pins), to leave a rounded button end instead of using a riveting hammer directly on the rivet's head. Using a nail set ensured there was much less chance of damaging or marking up the surface of the piece/sheet.

The first afternoon I used the Escutcheon Pins as they came from my supplier, work hardened, most likely half-hard. I found that it took many more hammer blows than I thought I'd need especially for brass. This had me thinking about the hardness of the pins so I decided to test out my theory by annealing a dozen plus pins as an experiment on my second afternoon. I had much better results with my annealed escutcheon pins.


The three riveting techniques I tried, all using annealed solid brass escutcheon pins (18ga/1mm) and a nail set:

1. pin dome on the bottom, touching the anvil (hidden from sight inside/underside of the piece)
2. pin dome on the top, struck by the nail set (seen from the outside of the piece)
3. just the wire section of the pin, the dome was removed with end-cutters

I cut the wire using end-cutters so that the top surface of the cutters were held firmly against the surface of the copper sheet and the butt end of the wire or the dome was pushed up flush against the bottom of the sheets I am riveting.

All work and look good though give a different look on both sides. I will be using the method that works best for the strength of the section I'm riveting, #1 or #3 mainly.

1B: The bottom row of rivets and the two rivets on the top left corner are the solid brass escutcheon pin that have the domed heads left on the back/bottom/inside of the piece. The closing of the rivet is done on the front/outside using a 2/32nds Inch nail set. The pins were annealed before hand.

The other rivets...are the leftover lengths from using the end with the dome as a rivet. I flattened the cut end using a snap-on sanding disk to grind/sand it flat. This removed the V left by the end-cutters and I found that this extra step gave me better success and a better looking rivet. They look flat and just about flush with the sheet's surface.

The flattened circles are the squashed pin heads/domes that are the anvil's surface when the wire is hammered from the top. The force of the hammering flattened the dome a bit.


TOOLS:

- Solid Brass Escutcheon Pins at least 3/8" or longer. Choose the Gauge/diameter you prefer.
http://www.leevalley.com/us/hardware/page.aspx?p=40385&cat=3,41306,41325
OR use wire of the Gauge/diameter and metal type that you prefer

- Center Punch, to make a dimple for the drill bit
https://www.riogrande.com/product/european-fine-center-punch/113329

- Drill Bits, the same Gauge/diameter as the Escutcheon Pins or wire. It is vital that the wire fits snugly in the hole and that it doesn't have wiggle room. The better the fit, the better your results.

- (optional) Round Bur, 2-3 times wider than the drill bit's diameter, to debur the drilled holes
https://www.riogrande.com/product/lynx-round-burs/344338gp

- Nail Set, 2/32nd Inch (when striking the wire) and 3/32nd Inch (when striking the dome) of 18 gauge Escutcheon pins. You might need different sizes based on your wire gauge choices, experiment to find the correct match.

- Anvil

- (optional) Rubber Bench Block, larger than the anvil

- End-Cutters
http://www.canadiantire.ca/en/pdp/maximum-high-leverage-end-cutter-8-in-0584311p.html#srp

- Hammer, I used a 8 oz. Stubby Ball Pein Hammer, Pittsburgh
https://www.harborfreight.com/hand-tools/hammers/8-oz-stubby-ball-pein-hammer-95930.html

- a torch and proper set up for heating/soldering metal for safety due to heated pins. I didn't pickle or polish them before riveting, they will get polished once I do a final touch up polish on the whole piece.


For filing the wire ends you have a choice between using a file OR

- medium or course, E.C. Moore Brass-Center Snap-On Snap-Off Paper-Backed Aluminum Oxide Sanding Discs
https://www.riogrande.com/product/e-c-moore-brass-center-snap-on-snap-off-paper-backed-aluminum-oxide-sanding-discs/337823gp

- Snap-On Mandrel for the sanding discs
https://www.riogrande.com/product/snap-on-mandrel/333127