Tuesday 17 June 2014

Saturday Strife & Sucess



 Saturday day dawned, too bright and too early given the night before's fun,  If you are near the shire and there are dice, we are likely to ask if you want to join in a simple game.   Roll the dice, take your number and hoist your glass every time it comes up and whenever double ones are rolled, Cheer and toast our fine kingdom, "Ealdormere!!!"  I'm a simple shire folk, from Trinovantia Nova, so I'm partial to the game as a good warm up before going off to other gatherings.  The mornings, however come too swiftly sometimes :)

So when I wake up bright and shiny at birdsong o'clock and began my day, it was a bit of an effort.   Wind there was aplenty, gales of it blowing off the lake, making standing down wind of the hearth a bit tricky.  The chill of it made me a bit insensible to the touch of sun that I earned own my shoulders early that morning.

The bellows stone began the day in three pieces, so I shored it up with rocks and pegs to hold it through the rest of the day.

I began first thing by relighting the hearth and starting up one crucibles packing it with of 50g copper and  setting the molds upside down in the second hearth and setting just a few pieces of charcoal in that hearth to try to gently warm the wax out of the mold, whether through it heating too rapidly or just the stress of contraction around an object 80% of the molds split.  I think this may just be a tendency as this also happened in the very controlled kiln firings earlier in the experimental process.     After all signs of the wax was gone, I began piling the charcoal on to fire the molds through,


Myself, earning my sun burn, and fussing with main hearth, while my very kind assistant (Yvette ) helped me tag off on keeping the the air flowing to begin to melt the copper.

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Working some more on my soon to be crucible tongs.
While waiting for the first crucible to get up to temp.

While working slowly up to a good heat.  1 hr at a gentle pace to get the worst of my crucibles up to temperature and then another hour at a moderate pace and  then about 20 minutes at what we could best describe as a gorilla running the bellows' pace'.    In the end we were able to melt the copper (apx 2000'f ) and then add the alloy and then I poured it off into water as casting grain to get a good look at what we had made, since the molds weren't yet ready.  It had good flow and colour and on the few stingy bits a fair bit of ductility. 
Fiddling around with it, checking on the crucible,  the hairline crack that had begun to open up, the fluxing on the outsides, it's contents and generally learning more about charcoal fires.

The first successful pour was just slightly after this picture and then we took a break for lunch after piling some more charcoal on the mold hearth.

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After lunch I inspected the now glazed and abused crucible and it's top and made the call that the next two would go in but should probably be turned every time we changed bellows operators, every 15 minutes or shovel full of charcoal apx.  That way the damage and stress of the blast side of the hearth could be mitigated.

In the crucible, closest to the bellows I put the freshly alloyed copper alloyed with 10% lead free pewter (rio grande) and in the second I packed another 50 g of copper. 

At a full 1 bellows per second speed (about) this sort of fire can be achieved, hem and only slight scorching of the cabinet occurred :)

My first, start to finish viking cast ever, immortalized, way too hot glove, hitting the guyline, cursing, and all :)

Petov, another of my excellent bellows volunteers, also of note are the lady AJ and Jobjorn (sp) who each spelled in for a while as their days allowed. many others helped through the days by bringing me food and water, and taking pictures and video and generally keeping company with us and helping talk to the curious when I was too focused to do that good work.
It looks a right mess but this is a day well done, with the ashes scattered, crucibles cooling and my worker bees and myself just chilling on the lawn and wondering about dinner and massages.



My wee little Upsalla birds!  Both have significant but clear and obvious problems.
1- both of them had charcoal bits and or ash  fall to the lowest part of the mold.  Tamping gently upside down just prior to casting and or adding a relief spot for this should solve  the problem.
2- neither of the molds and or the metal was hot enough to give sharp detail.  I think the molds were too cold, but being quicker on the pour by being able to be on the right side of the forge  (baring inconvenient winds again) should in combination, make for a very nice, crisp well filled mold. 


This above is the first crucible I alloyed in. It was the only one that had a hairline fracture and I wanted to
know how it would hold up, the answer is, surprisingly well, it's not in great shape, but it did the job.

The other two faired better, in part because we knew at what colour of heat things would be melting and I also think that the turning helped distribute the abuse.   I am interested to see if these external cracks continue to develop or if they will stabilize at some point.  Others who have done this sort of casting have said that they can get about 10 firings from stoneware molds, time will tell.



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A sad end to a cute bellows stone, much more grog next time, but really I'll try some soap stone if I can get my hands on it reasonably. I'll need about 20-25 cam square and about 3-5 com thick

Some very crude glass/ fluxy material was attached to two stones that were just below the outlet pipe of the bellows.


The end...... of the day,  but not of the adventures.  Bigger better and more to come.
Orla

Sunday 15 June 2014

Forging Ahead Friday

I have had an incredible weekend, Progress, struggles, frustration, joy and successes all in small measures.
To begin the weather was quite windy all weekend but bright and mostly dry :) I had been gifted a canvas tarp by the Lady AJ that had been used to shelter many a girl guide fire so it was tried and tested against sparks and all I needed was to hunt for the right wood to make a nice light sunshade. 


Shelter secured and permission to set up the forge (above ground only due to site concerns) had me scrambling all week to cobble together a small 'pit forge'/ sand table out of an old corner cabinet and some determination.    

I went into the scrap bins I have, and every piece of copper 'too' small, bent, twisted abused or failed scrap that I have kept over the years was cut up finely to use to make the bronze.  

 I portioned up a series of bags each with 50 grams of copper and then poured off a number of ingots of lead free pewter to hack up into 5 g bars.    I used a counter weight balance scale,  a small step away from the Norse versions but low tech all the same.  I had some fun distracting myself from the possible ideas regarding another avenue of "hey I could make one of those..."  In the end practicality won out and contented myself with thinking through the steps to use one to weight and portion out alloys while I continued the monotonous task of hacking up copper bits.
There's a ton of really good info out there on norse and anglo weights and measure but I fount this authors brief post especially interesting http://vikingmetalwork.blogspot.ca/2012/11/standardised-viking-weights-part-1.html  She has written a few books on the subject of viking jewellery and I hope to have some more book purchasing power soon to indulge my curiosity beyond the teasing peaks I can get with google books.




So in short order I had a nice display area set up and roped off.  The sand and stones were acquired and laid out in a small pit about a hand-span wide and half that deep lined with rocks and with the bellows set on only one of the pits.


Starting up the charcoal fire with some handy teasels, 
Now there's not much more to show in images on this day because I spent most of it forging a pair of tongs and was kept too busy to remember to take more shots.  The only blacksmithing I had done prior to this was by using a torch for small projects like chasing tools, working this way was completely foreign to me and a great adventure. Learning how and where the heat was and keeping the iron in the right spots in the fire was enough to keep us playing till dinner.   The bellows preformed reasonably well though the valve on the 'lefty' is a bit slow to close and requires a wrist flick to get to work well.  

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It was around an hour or two in when some of the hairline cracks in the ceramic stone succumbed to the internal thermal stresses and gave up the ghost.  Two main brakes were visible, but since they were well keyed into each other I left them and just ensured that the stone was well staked up so that if parts fell it wouldn't be into the hearth.  It was a sad event but not unexpected in the grand scheme of things.  I will have to get a line on a slab of soap stone or some other fire resistant stone when I have the time to make a nice one again, In the meantime I learned that the size and shape of it did indeed work very well. 


At the end of the night when everything was cooled off and put to bed we made a trip out to get more charcoal just in case because it looked like, by the consumption so far it would be a good idea, and boyo was I right, the brand I bought the first time was the big blue bag, Royal king I think, and it was a bit of a pain because there was a huge range of piece sizes and some of then weren't even charcoal yet!  At the local grocery we found a different brand and it worked very well and was in nice small and even pieces.  So much better,  I understand that bag to bag there'll be some differences, but to boot, this other stuff (Duraflame lump charcoal, 100% natural) was a few bucks cheaper so I will keep my eye out to pick up another few bags for my next demo at an upcoming event (Trillies).

Wednesday 28 May 2014

Waxy, Windy & Shiny

As usual the making of objects is way more fun than the writing about them, so this update's going to start in the now and slide backwards to our kingdom's spring arts and sciences event.

I just washed up and got all the last of the clay off my hands from making a ceramic bellows stone.   Most of these in this period were made of soapstone or shale that would over time flake and spall under the heat of the forge, but they were often still decorated.   The ceramic ones were often augmented with grog and other additives.   On a side note I am not ashamed to say that I will be pleased to try adding horse manure to some of my future molds now that I will have a friend with easy access to the goods.  This pattern is from a paper in which I can only read one word in ten, but metric measurements and a helpful article summary make a world of a difference when reading resources in another language. :)    



 Went hunting last week for a few more simple shapes and designs to carve. I'd say we're getting out of the season of bees wax carving unless I keep a bucket of ice water handy, it's just too mushy to work well for me.

http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=85089&partId=1&searchText=strap+end+anglo+tinned&images=true&page=1 

This one below worked up relatively quickly and will be a good test run for 'filigree' to see how well it will fill.


I made a few little three sided scrapers/ borers to work on the waxes and these helped though I also used a fine knife an awful lot.


There it is, up in the top right on top of the photocopied template... I like them enough that I'm going to temper them so that they will keep a better edge.

And then.... There came a great wind... and it was good and it involved many, many many tacks (275+) and a fair but of hammering.  Really this is almost the kind of woodwork I could get behind.


I made pretty and fiddly handles. Nice, but good odds I'm just going to wrap them in leather for comfort. I was feeling the need to make the tools appealing to use, I find if I love a tool, I'm more likely to enjoy using it.

Temporarily wire is wrapped to a board that could be staked down. I'm not settled on how I'm going to use these, I'll do a ground level test run , and frankly if it works and all my helpers are comfortable it may a more period way to go about it than using a raised sand table.   Though I do suspect the latter to be more comfortable for working.  I have an old corner cabinet I made in grade 9 shop that has no home in my house and is really, really likely to make a very nice upright forge.  
Using door hinges as recommended for durability under *hem* volunteer 'usage'.

 Oh look! I finished some things.  :) Good thing too, I've begun converting my friends to be 'Camp Norse' and needed to loan out my old brooches.

A&S went well, good feedback from the judges and I picked Sylard and Ragnar's brains about the bellows.  It more or less boiled down to " Have you been to the DARC Website?"   "Yes..."  "Good, do that, the measurements should all be there"   Succinct and true enough.  I hope these pages help some one think they can take on these adventures too some day.  See, it's not too crazy.... right?

Monday 24 February 2014

Five by Five

So I've been shoehorning in an hour here and an hour there between paying work to get my waxes in good shape for a day of casting.  Then to my good fortune I had a full weekend at home and some paid castings to do for work as well.

Waxes, ah how I love them, so much potential, with such a humble materials.  Modeling the details back into the copied waxes is really best done in a cool room which in the case of my basement is nooooo problem (concrete floors suck). 
In this first picture, from left to right is the "master wax" and then the copies starting from 
untouched, fresh out of the clay, to 100% finished up.
\Here are the finished waxes with little tapered sprue nubs for where the metal will be poured in.
And then there was grog.... Grog you say? This doesn't look like rot gut booze... It looks like smashed up earthen ware.... Why yes! It is :) and all this smashing fun in an effort to temper the clay to reduce the shrinkage rates and stress during drying and firing.
I sieved it because I could and also 'cuz too large particles will cause troubles.



You can actually see the colour difference in the two types of clay here. The grog-ed was added at 1/10th by weight of dry grog to workable clay.    I used it for the crucibles and one each of the two types of models.
 
 There were some drying issues, mostly along a seam on one brooch and at random along the middle of a belt end, the first is predictable and can be moderated by better blending seams. The second may be a result of not enough support when drying. The lip of the sprue collar stands out by about a cm leaving a long span unsupported in the middle when it was drying.  I'll try drying it on its end and more slowly next time, perhaps 3-4 days in plastic as opposed to 2.
I did try patching the one break...


Clearly to no avail. One mold broke cleanly along it's seam and the other broke in two parts after being fired up to 1800'f .  Really the molds didn't need to go up to nearly that high but I wanted the crucibles well fired and the molds were along for the ride.

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After letting the kiln cool down over night I pulled everything out and wired the broken pieces together.  In small batches I alloyed my bronze 4 parts Copper scraps to 1 part lead free pewter (from rio grande)
Till I had as much as would fit, 75 grams, this is also about the max that I can get liquid in any reasonable time with my wee jewellery torch set up. 


Not knowing how the wiring would hold up, but game to try I heated up the kiln with all my molds in it to 250'f  and let them soak up the heat for about a half hour.   Then to test with pewter first...




A clean pour with some drippy-ness out of the cracks, but not too bad.



Then to brave the bronze in a slightly less broken mold.  


And while that cools it's time to start chipping away to see if the first pewter one succeeded.

" Oh! How cute! Aloo' little wolfie... Please be all in one piece."

 VICTORY!   And ooooooohhhhh,shiny!
 You can see where the break was there is some flashing and fins, but these are easily taken off with pliers and snips.
Next UP! Bronze, the batch alloying went much better so this mix had really good fluidity and it went into the mold without even a leak.

 A few more pours later, while still bouncing with the joys of successful casting (failure would mean all the hours carving the waxes would be lost so I am a Happy Goldsmith)  it was time to figure out how to crack these nuts. When to quench, and where to strike to get useful cracks and breaking was a bit of fun figuring out, but by the third one they were coming out with very little fuss, 




  
I kept this one's clay front as a good sample/example for when we do demonstrations and talks with the SCA. 


 A fast, dirty and very period way to cut through metal. 


A few months work made real in a day, never minding the time it will take to clean them up and install their pins.  On a side note, though I didn't take any image of their undersides all of the pin hooks and hinges turned out and I made them in three thickeness' in case the reason the first ones didn't cast was that, and they all turned out exactly as carved. So I'm going to guess that the earlier trouble were caused by the slugishness of my first botched try at alloying bronze.  . 

What's Up Next... ?


Patience... I haven't a hope of casting these without a forge setup so I had best get to making and finding all the parts I need. In the mean time, I'm sure I'll find something to keep me busy.   


Sincerely, Orla.