Friday, July 31, 2009

Ideas? Forms from Nature

One trend in artistic blacksmithing is duplication of natural forms from nature in forged steel.

The classic standard is making steel roses, attempting to perfectly duplicate the real in metal. Although there is no doubt of the craftsmanship involved, I personally find the creativity quite limited. My own taste (obvious in my work) is to the more imaginary lines of Art Nouveau.
That being said, Nature is endlessly inventive:

I am always amazed at how 'fantastic' real natural forms can be. Making metal roses may be difficult - but...

Wednesday, July 29, 2009

" I love it when a plan comes together..."

If you have been following my work (as described here) over the last several months, you will seen my main focus has been on the Reade/Maxwell railing project, for a custom home on Manitoulin Island.
Monday and Tuesday this week, I packed the truck and headed off to the ferry to the Island. On board were the first three completed panels, plus the two heavy support beams. The panels were the 'rushes' element of the overall 'sea to shore to sky' concept for this open layout building.

View 'south east' from the living room area.
View 'south west' from the head of the basement stairs.
View 'east' along the line of the balcony opening towards the basement.

Of course, forged work railings are notoriously difficult to photograph! These images are clearly 'in progress'.

One thing that is clear, the light lines of the interset individual rushes allows the light and view through the floor to ceiling south wall windows to clearly show through - as was the intention of the design. Another thing that these images shows is the impact of the colour. These panels are not black, but are a very dark green.

Thursday, July 23, 2009

..but can you DRAW it?

Increasingly, one of the problems I have is related to my rendering abilities (or lack thereof). As the objects I imagine become more complex, and more three dimensional, it gets harder and harder to represent them on paper. In some cases it takes almost as long to draw something as it does to actually go out and make the thing!

LEFT:'Undersea' newel post
ABOVE:'Kelp' railing layout

This is my layout for the next element on the Reade / Maxwell project. This is the terminal post for the diagonal railing that runs down to the basement.

In the overall series of designs, the concept has been 'Sea to Shore to Sky'. Inside the concept, I have been repeating the use of certain forming techniques and physical shapes. One of these is the use of angle - heavily reforged into organic forms.
The first idea I had using this material was the 'kelp' element seen on the layout for the diagonal railing seen above. One end of the material is carefully forged into a roughly oval 'stem'. The other is flattened, then here is formed into a series of reversal curves. At this point it has not been decided if the individual elements will be mounted as shown (mass down) or more like natural kelp (with the reversal curves topmost). To the point of this discussion on rendering, you will note that I used some hoodoo with Photoshop to produce the illustration - rather than tying to hand draw it.

For the newel post, the idea I had was something that suggested a whirlpool in the water. I had also wanted to have the element to spread over the basement floor. In the final design (though yet to be approved by the clients) a bundle of four of the kelp stems rise from the floor. About half way up, these flatten to leaves, which spread out then swirl into a spiral cylinder.

Ok - now the rendering. I have been carrying that design around in my head for a good month. I have been rollling the possibilities of the forms, both as individual elements and as the final combination around in my imagination. Coupled with the raw design has to come a consideration of the technical aspects. You could easily imagine an object that in end you just could not physically make!
That illustration (poor as it is) is the result of many hours of pondering. It took me roughly an hour to actually draw. Even still, it certainly is NOT a photographic or even a plan view of what the actual element will look like when it is finished. Hopefully it is detailed and accurate enough for the client to undertand. I myself do not really require a drawing, as that long considered object is firmly planted, in considerably greater detail, in my mind.

First rough concept drawingCustomer LayoutAs forged and assembled

I want to stress this last. An true artisan blacksmith will be balancing imagination and technique in each design. They also will not be slaves to the established layout. The final shape of any object is a result of a force vectors applied to the metal by the combination of each individual hammer blow. This may be the end product of hundreds of individual strokes. Yes, and experienced blacksmith should be able to both predict and control the shaping of a metal bar. The 'art and mystery' comes from working with the developing dynamic process, of knowing when to force the material to your intended design - and just as importantly, when to 'let it go'. Sometimes the metal just wants to be a different shape.

The three images above show both an object that shifted during its creation process in just this way. More importantly, the two illustrations and the finished object also indicate another important aspect of creating original art metalworks for a client. No mater how great your ideas, you do have to be able to communicate to the customer!
This is my design to finial creation of the upper newel post at the head of this same set of stairs to the basement. Here the theme is 'shore', with stylized rushes making the railing uprights. The first illustration is my own thumbnail for the newel post. It needs only be extremely rough, as the full object exists in my imagination, and this is more than enough to remind me of my intentions. Although many hours lay behind that drawing, it only took a few minutes to sketch it out. The second drawing is clearly more refined, and is the layout illustration I presented to the client to communicate my ideas. You will see it includes some technical notes, on stock sizes, forming steps, and the like. When I sent this illustration to the client, it was accompanied by a full page of written description, in even more detail than the illustration. The last image shows the element as it was finally produced (here welded to the associated hand rail and ready for paint). As you look at the sequence, you can clearly see how my original concept was refined and modified though the process. Although the exact lines of the customer layout are not duplicated in the final forging, it is clear that the illustration does represent that object.

One final note: I have just spent a further two hours (!) writing and formatting this blog post. Why?
One of the aspects of working with a client on any custom art work (especially one as large as the current Reade/Maxwell project) is communications. I balance the inaccuracies of my simple style of layout drawings with considerable effort in informing the customer just what is happening here in the shop. For this project this has included not only phone calls and private e-mails on a weekly basis, but regular commentaries on the work in progress, including video clips (posted to YouTube and duplicated here). For this project, this all has proved to be the ideal way to keep the customer 'in the loop' as I continue to work (and eat up their considerable deposit funds!)

Wednesday, July 22, 2009

IRON Mandrils - Iron Oxide bead release?

(Cross posted from the DARC Blog)
"Ancient beads were often made on cast iron tapered rods, without the use of a separating agent. Once a bead was finished, the rod was heated to red-hot and plunged into a container of salt. This created a chemical reaction, causing the cast iron to rust and the bead could be easily tapped off the rod."

Quote from

(Note: In all fairness to Jhan, her interest lies in duplication of historic beads using modern flame working tools and methods. She clearly references that someone else told her this, so I am not critical of her otherwise quite good web site!)

First, what is being referred to here are artifact wrought iron mandrils. Two have been found in the Viking Age layers at Ribe, Denmark. (This is the focus of interest of Neil Peterson's experiments with DARC.)

As an experienced metal worker, I do want to stress the actual material. There is a significant difference, both chemically and structurally, between the various different iron based metals that might have been used. This also extends significantly to the oxidation rates.
I know that 'cast' iron was not used historically. This high carbon alloy was not clearly understood or widely employed for any purposes until into late Renaissance times (varies depending on location, much earlier in the East).
Most likely is some form of bloomery or wrought iron, the low carbon material most commonly used for all forged objects up till the Industrial age.
For comparison, modern mandrills are typically a nickel alloy (stainless) which basically did not exist until fairly recently (the Modern Age - say 1900). This material is used because of its great *resistance* to oxidation.

I have made up one actual 'wrought iron' mandrill, using antique recycled metal (on a guess from the late 1800's). This specific material most closely matches the bloomery iron that would have been available during the Viking Age. The form is (loosely) based on one of the artifacts from Ribe. The shaft is about 30 cm lng and is mounted into a wooden handle. The fairly heavy cylindrical body shoulders in near the tip for about the last 3 - cm. The diameter here is roughly 3 mm, tapering slightly to the end. To date we have primarily been using a fairly standard method of coating the working area with a clay resist.

I have reservations that the theoretical salt water quench method as described would actually work in practice. There are two primary forms of iron oxide in play here. Chemically these are Fe3O4 or Fe2O3:

The first (Fe3O4) is the high temperature form - black oxide or fire scale. It is hard, brittle, and adheres both tightly and strongly to the parent metal. Its formation is fast - due to the temperatures (above about 450 C or so). I just can not see this being of any value to the bead making process, as the glass strongly attaches to this layer, then due to the bond between the oxide and the metal, it remains firmly in place.

The second (Fe2O3) is the low temperature form - red oxide or rust. This layer is soft and crumbly, and breaks away easily under any mechanical pressure. Generally this is a slower formation, taking place at room temperatures. This process is accelerated (ask the chemists why) by water, and a bit more so by salt water. Now, it might be possible to use this layer as resist, as it does easily break free from the parent metal. This layer is certainly extremely thin. This presents two problems. First - there is not much separation layer to begin with, so it would be extremely easy to scrape it completely off and expose the metal underneath. Second - the layer is so thin that it conforms closely to the shape of the parent bar. The interior of the glass wraps tightly around any irregularities in the metal mandril. Although every attempt is made to produce a mandril with a perfect cylinder, or a slight conical section, one of the functions of a thicker resist layer is to lift the glass away from any imperfections. Such a thin layer as the oxide would create would just not give enough gap between metal and glass.

I should mention that one observation I have from forging actual wrought iron is that when it is quenched from incandescent in water, often a thin film of red iron oxide will form on the surface. As suggested, the quality of the iron does effect this. However, given the problem of creating a suitable 'release gap' I still think that this natural oxide layer is just not thick enough. Even with the slight acceleration produced though the use of salt water, the layer of Fe2O3 created would far to thin to be significantly useful here.

I suspect that this whole idea was theoretically reverse engineered to explain observations of a special situation. I believe (?) some glass beads were found to have a very thin layer of iron oxide in the interiors of the holes. How to explain this? Pair this observation with the discovery of a couple of wrought iron mandrils. Presto! A working method, now enshrined in the literature (although never actually tested). Repeat that WAG, until it has become an accepted method (still not tested).

An alternative : given the wide availability of various iron oxides as ochre deposits, perhaps a well known resist material was simple red ochre mixed with water as a paste. This applied just as we do our fine clay. This is a method that would be easy to test experimentally.

Additional tests:
- As Neil Peterson has mentioned, examine only BROKEN artifact bead fragments from production sites to check for the presence of resist. We know that the thin clay layer is fragile, and relatively quickly will clean away from the interior of any bead actually worn on a string. This does tell us beads found removed from production sites may not yield useful information.
- We tend to take a very long time to make a single bead. Historic production work is sure to be much faster. The way the clay interfaces to the glass is sure to be time dependent. Is there any way to check on this?

Monday, July 20, 2009

Working / Temperatures - VA Bead Furnace

(cross posted from the DARC blog)

Peterson Mk 5 Bead Furnace - July 18. 2009Showing the overall layout of working ports on the furnace

The Mk 5 furnace is again laid out with working areas for two people, one on either end of a roughly oval furnace, which has air input and charcoal loading on either sides of the centre. At the top centre is a built in cup for annealing, for this test holding sieved wood ash. The loading port (not seen here) has a second cup which inserts into the opening. In this test this second cup held vermiculite.
Each worker has the choice of using an upper port, allowing for manipulation of the glass in the hot exhaust gasses. A second covered port in the side of the wall can be opened, allowing for working down inside the body of the furnace. This method was used for experiments with tesseri. (see the video segment posted earlier)

A thermocouple type pyrometer was employed to roughly measure exhaust gas temperatures at one of the top ports over the experiment. A roughly 6 mm (1/4 inch) diameter hole was drilled into the wall of the furnace, just down from the lip of of the port. The probe was extended into the opening about 1 cm. Although the probe was placed early in the experiment, and readings were constantly monitored, unfortunately the recorded data only extended over a relatively short time sequence:

Temperature Data (C)


charcoal fill

change method

adjust charcoal

adjust charcoal

By Darrell Markewitz

Sunday, July 19, 2009

Beadmaking - Working with Tesseri

(cross posted from the DARC blog)

Neil and Karen from DARC held a workshop / experimental session on Saturday July 18. A small group of us spent the afternoon working with the Mark 5 charcoal bead furnace, primarily working out the best firing dynamics and continuing to transfer our skills with modern torch working methods backwards into the Viking Age.

The furnace used above is based on base plates found in the excavations at Ribe, Denmark. The superstructure remains speculative, being refined in detail as our working experience increases with the equipment. With each session, the ratio of successfully completed beads increases - a sure sign that something is improving!

One note - for this last session, a modern electric blower was used to supply the needed air.

Saturday, July 11, 2009

Bead Furnace - Gas Jet 3

... referred to (why?) by Neil and Jean as the 'tea pot' style.

About the time Neil Peterson got seriously interested in compiling tables detailing just what forms, colours and shapes were common during the Viking Age, I had been introduced to the modern methods of making lampwork beads. At Dan Nickels' 'Folly in the Forge' workshop, a local glass bead maker had demonstrated the basic technique. Along with fellow blacksmiths David Robertson and Janis Book, some basic supplies and Corina Tettinger's (excellent) manual 'Passing the Flame' were purchased. Over the next several months, I had made about 100 beads using my oxy-propane torches, gaining at least a basic understanding of how tohandle hot glass in rod form.

Neil's experiments proceeded with a furnace based on the base plate remains from Ribe, Denmark, with a superstructure suggested by traditional Indian models. These used a dome like enclosure, with small working ports into the interior to contain the required heat. The glass would be manipulated inside the furnace through these ports. Neil is now working his fifth version based on this system.

In spring 2008, I had a chance to meet with Trene Theut, an artisan interpreter at the Ribe Viking Centre, and its glass bead specialist. At that meet, Trene described her most recent experimental furnace. The next day I was able to see this furnace on my visit to the site itself.
(Trene's Experimental Gas Jet Furnace at the Ribe Viking Centre)

The initial concept behind Trene's set up was to trap and utilize the hot gasses from the charcoal fire, rather than work inside the furnace itself. The combustion gasses escaped from small vent in the top of the roughly cylindrical clay structure. In this way the manipulation of the glass was physically more like working with a modern torch flame.
Although not designed specifically for this method, those working with Neil's 'oven' design, more and more were found to manipulate the glass in the 'chimney' holes in the top of the structure. (See Video Segment)
(Mark 2 'Teapot' Gas Jet Furnace in use)

To that end, a first two attempts at a building a specifically gas jet furnace were undertaken in May and July this year. This specific layout was quickly found to be quite unsuccessful, as the upper gas jet never produced enough heat to do much more than slump the glass rods used as a raw material.
Taking a close look at Neil's first renditions of the system, I thought I could apply some of my experience with charcoal fired forges to the design.
(Theoretical Gas Jet Bead Furnace - scale 1:2)

One of the biggest problems with the Mark 2 layout was found to be the sloppy fit between the large side loading port and the inserted annealing cup. The large gaps here were found to be venting as much (if not more) of the hot combustion gasses as the top working vent. One of the largest changes in the new furnace is that instead of a side loading port for charcoal, it is designed in two sections so that the entire top can be lifted off to add fuel. The top rim of the lower section is beveled, so that the upper body would quickly slide back to the correct location when it was replaced after loading.
A second major modification, is the change in the shape of the lower section of the furnace. Rather than an elongated D cross section, this proposed furnace is more of an 0 shape. The bellows tube is placed so that the distance below the furnace is roughly equal to the side to side measurement. This will allow the air blast to completely penetrate the charcoal mass, as well as cause any piled fuel to move down and into the air blast as it is consumed. A small hole into the interior, located roughly two inches above the bellows tube opening, would allow the operator to directly observe when the top of the charcoal had dropped to a level where addition was necessary.
In this arrangement, the bead maker sits directly opposite the bellows. There would be a small port with replaceable cover at the middle level of the side wall, allowing working of tesseri inside the furnace itself. (This using the method discovered at the Trillium demo, detailed in an earlier posting.)
Most of the detailed glass work is intended to take place in a second small chamber placed at the top of the furnace, directly over the exhaust port for the combustion gasses. This would have a single small opening, placed on the side closest to the glass worker. The very top of the furnace would have a shallow cup, intended to be filled with ashes to provide an annealing area headed from below.

With luck a first prototype of this modified furnace will be built and tested later in July.
(original post modified when Karen pointed out that TWO earlier versions of this type of furnace were constructed. The first was constructed and test operated during the iron smelt weekend May 30 by Neil and Jean.)

Monday, July 06, 2009

Glass Bead Making Furnace

(duplicate post from the DARC blog)

Neil / Ragnar working with the mark five experimental bead furnace.
Trillium War, Whitby ON - July 4, 2009

This furnace is based on the base plate remains found at Ribe, Denmark, dating from the early Viking Age. There was no superstructure preserved, so a number of top designs have been experimented with. The combination of top vent and side port with cover appears to be the most flexible. Most likely a mark six design will be built, as new knowledge is gained every time a serious work session is undertaken.

One key techinque was stumbled upon (pretty much by accident).
An ongoing puzzle has been how the Norse worked with glass tiles (tesseri) as their source of raw glass:

This is a direct method (rather than involving a melting pot or creation of glass rods as intermediate step).
- work is done inside the furnace through a side port
- glass tiles placed on flat surfaced piece of charcoal (which can be used two or three times)
- wait till glass tile heats till edges just start to slump
- make sure your mandrill is well heated (to orange)
- touch mandrill to one corner of the tile to affix small corner of glass
- raise and twirl mandrill. This effectively pulls a stringer shaped finger of glass off the tile.
- now the process is like working with a rod, thickness of the stringer is controlled mainly by height the mandrill is lifted above the tile.
- This appears to reduce the amount of ash contamination, plus produce a correctly shaped bead (rather than the irregular shape produced by grabbing the entire tile at once.

Check the main DARC web site for more information on Neil's ongoing research and experimentation into VA glass beads and their production.


Wednesday, July 01, 2009

Canada Day Beaver

A surprise visitor to our small pond, June 30:


Bob and Doug would be proud, now much more Canadian can you get than a visit by a BEAVER?

Our one acre lot in Wareham has a small pond in the back corner. A bank of earth separates it from the creek which runs just back the north line of the property. There is a small but noticeable 'game trail' that leads from the NW corner of the pond for the last several years. This year I have been finding cut off leaves and torn up roots from the clump of bull rushes that grow in the shallow south end of the pond. I was a bit puzzled as to what might have been doing this.
Caught in the act was the fellow seen above.

View facing NW, the beaver was foraging in the lower left corner.

I shot the footage standing along side one of the posts in the smelter shelter. We were able to watch the beaver munching on both rushes and some small willows we had planted on the SE bank, for a good half hour. Eventually it started to rain and we went back inside. (Now I know why those willows never seem to get any bigger than knee tall!)

A real treat, especially the evening before our National Holiday...

February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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