July 4th, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
I have been very slack with my pewter work over the last 6-8 months and as such I have gotten a little behind. In order to attempt to get back on track I’m publishing the list of pending jobs in the order that I need to complete them.
- Current project for Their Majesties.
- 80 – 100 x Radburne War Event Tokens (Annual Commission).
- 3 x Coronets for Their Excellencies of Mordenvale.
- 50 x tokens for Kotek, Kingdom Chirurgeon (Also need to ship the first 30).
- Coronet for Cortaine.
- Finish 2009 Period Archery cup for Maddog and 2010 Cup.
- Private Commission.
- Owl Tokens for Owain.
- Sun Tokens for Catherine.
- Pewter Tablero set for Myself.
- Further Experiments in Drinking Vessels.
Any further jobs or projects asked of me will need to fit in-line with this current list. I am estimating that at my current participation rate it’s going to take me at least 12 months to get to the end of this list. I will still consider bumping the list for commissioned event tokens as event tokens are the reason I got into this hobby and I’m a strong believer in events having commemorative tokens.
If you have previously commissioned a project from me that is not on this list then please contact me however I do believe that I have listed all currently commissioned projects. There is however one group that I do owe 40 tokens to, however I am still awaiting their design, and that is not listed.
Posted in: Uncategorized
July 4th, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
…’Cause it really is not the actual casting bit.
I’m finding the actual casting of these current tokens very frustrating. I would really like to know from other casters out there what the failure rate on your casts are, cause at the moment I’m getting about 2/3rds failures. I’m also not exceptionally happy with the quality of the other 1/3rd that I have been keeping and often just give up on a particular pour all together.
Is the mould meant to get so hot you can’t actually hold it with welders gloves? Does preheating the mould actually make a real difference? If so… what Temp do you preheat to? I have found that I tend to get the best results with a cold mould that has a big enough opening to allow a full pour without allowing pockets to form, though I have also found that it is very hard to get that to work when you are casting thin tokens as the pewter freezes before it can get into all the nooks and crannies.
Advice anyone?
Posted in: Uncategorized
July 2nd, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
Well… As it has been pointed out to me plaster can’t seem to cop the heat needed to be casting more than about 20 tokens. I’m sure that the size of the tokens and the size of the button required to supply the pressure needed also didn’t help. Due to the time issues I am left with only 2 choices…
- Forget the experimentation and carve a back for the mould out of soapstone, basically going with an option that is known to work
- Try again with a different medium and hope that the experiment will produce at least 25 usable tokens. If I did go with this option I would consider using clay as the main alternative medium as I believe it would hold together better.
Another option is to get some hard wax for lost wax casting and use the current mould to make wax tokens that I then add to a huge wax tree and cast 30-40 tokens in one go. I’m tempted to ask for help from a friend on this one, as I need to have the tokens made by Monday and I’m daunted by the task of having to hand carve the text. Though the idea of doing lost wax casting is also interesting.
Posted in: Uncategorized
Tags: #1002, pewter, tokens
July 1st, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
Over the last week I have been scrambling to get a mould made that was a little beyond my carving skill. The design provided was within my skill level, however the request was for a double sided token with wording on the back, and whilst my carving ability is fine for a few words in well… my best hand carved font, this required more words than I would normally be willing to carve, as it’s not just the carving of the words, but the remembering that it all has to be backwards for it to work in the mould.
With this challenge ahead of me I thought it was a good time to experiment with a slightly cheating, slightly non period method of creating the back half of the mould that I have been pondering on and off for the last few years. The complete mould would be a composite of a soapstone hand carved front piece and a composite constructed rear mould made from etched copper and plaster. This would allow me to easily create new rear pieces for any token with easily etched detailed writing or flat designs. Whilst the back piece would appear to be a more modern process, on most tokens it would only be there to provide context to the token and therefore would mostly be hidden during wearing.
After discovering a blog post several months ago about how to use a laser printer to transfer toner to a piece of copper to use as etch resist I was armed with all of the necessary skills to create my experiment, and when this job turned up with a rather short timeline I everything fell into place. Unfortunately as these tokens are to be presented I will not provide photo’s just yet, however I will go into a few more of the details of creating the mould.
After carving the front face of the token into a rather nice piece of soapstone, I then drilled three locating nipples around the carved mould so that the back mould can be located each time. I then proceeded to construct the back mould. The back mould will consist of a copper plate that is etched suspended in the correct location by a plaster block. After etching the copper plate with the lettering on it I soldered some anchor tabs into the back of it so that it would be held firm to the plaster once it set. I then mounted the copper plate in the correct position on the soapstone front face mould using bluetak, this allowed me to position it correctly and have it sit the correct distance from the face of the mould. I then constructed a mould around the soapstone so that I could pour in wet plaster. Once the plaster had set I removed the mould and the plaster from the soapstone and let the plaster sit for a few days drying. Plaster is very good at retaining water, so it’s best to either leave it for at least another 24 hours after the first 24 hours it takes for the plaster to set, or artificially dry the mould in an oven on very low for 3-6 hours.
In a few weeks time I shall update you on how successful the process is and how well the plaster and copper mould works, for now I can only tell you that initial testing is promising and that future un-hurried testing may produce much better results.
Posted in: Uncategorized
Tags: pewter
March 31st, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
The token I was having so much difficulty with. As you can see the technique I described below doesn’t completely stop the artefacts, however to completely get rid of those I need to control the temperatures and humidity a lot better than I can in a shed when it’s raining.
Posted in: Casters Note's
Tags: sveinn, token
March 30th, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
Recently I had some difficulty in pouring a one sided two-piece soapstone mould that I had carved because I had forgotten some of the “best practices” rules I have been slowly working out over the last few years. These best practices I shall consolidate into a post later, however for now lets just consider the solution to fixing this particular mould without having to entirely re-carve it.
As the mould was not generating enough pressure from the weight of molten pewter in the button I needed to find a solution that would allow more height in the button whilst not adding significantly to the cooling effect of the Soapstone. I achieved this by laying the carved mould flat and creating two extra pieces out of wood to pour through. The advantage of this was that the wood is quite a good insulator and allowed the heat of the molten pewter to remain until it spread evenly on the surface of the soapstone below. As the mould was flat this also allowed for a more even pressure spread across the face of the token.
I am tempted to create a generic RTV Silicon version of this method as the wood does tend to char and disintegrate over a number of castings.
Posted in: Casters Note's
Tags: observations, solution, sveinn
February 14th, 2010 / No Comments » / by Sveinn inn kyrri Grimsson
Greetings All,
I have recycled this blog in an effort to unit all of the Pewter Casters of Lochac and share our experiences.
I shall shortly be cross-posting all of the Metal Madness posts from my own blog over into this blog so that we can have at least some posts for people to read, however if you are a pewter caster in Lochac and would like to contribute to this blog, we would love to hear of your experiences, have you show off your latest works, read any documentation or just discuss the processes you went through to achieve you latest piece. This blog will work in conjunction with the Lochac Network forums casting forum, so feel free to join us in there for some general discussion and introduce yourself. For those of you new to casting pewter there will be some beginners documentation up shortly to help you get started.
Please feel free to get involved, as this is a resource for everyone not just me. 
If wish to contribute to this resource, or use it as your own means of keeping a project diary, then feel free to register and then email me to get your status changed to a contributor. Posts are to be kept to the subject matter of Pewter Casting and Medieval techniques. I look forward to hearing from some of you who might be interested in participating.
Posted in: Lastest News
December 15th, 2009 / No Comments » / by Sveinn inn kyrri Grimsson
I have just posted an article about creating a pewter drinking vessel to the Casting forum of the Lochac Network. For those of you who follow my Pewter casting, you can check it out by clicking on the picture.
Direct link to Lochac.net
It worked out great, and I look forward to making more.
Posted in: Casters Note's
Tags: cup, drinking vessel, sveinn
October 9th, 2009 / No Comments » / by Sveinn inn kyrri Grimsson
Finally! it’ been a while since I posted a pewter project post, but I have now got a few projects on the go so there will be a number of them coming in the next month or two.
This weeks project has been a personal token for an SCA member to give to those they favour. It is a simple medallion with initials on one side, and a raised representation of a logo/device on the other side.
Usually my medallions are carved into one side of the mould for depth and then the other side is smoothed and has the detail carved into that. For this particular token I wanted to attempt a fully symmetrical moulding process by carving half the depth into each side of the mould. I did this for two reasons, firstly, the one sided method I used previously whilst it makes for a nicer edge, usually needs alot more work to clean up. Secondly it allowed me practice in aligning the two halves of the mould, whilst the old method allowed for misalignment, it meant that the main image was not centred on the finished token, and it would look kind of wrong.
After some experimentation in attempting to get a good quality pour each time (see last post), I managed to find the best combination of temperature and mould tapping that resulted in a great amount of detail showing. This further experimentation also made me realise the importance of the mould tapping and the continuation of it until the entire button* has solidified. It seems that during the freezing process pewter can sill move past other parts that have frozen solid. I suspect this would be similar to the crystals of ice that form in water, they allow water to pass around them, but still hold their shape.
Interestingly this also brings to my attention the creation of another type of artefact on an improperly cast item. This artefact is caused if the mould moves during this crystallising phase of the freeze, and creates a texture like the one in the picture to the left. It is rather a fine texture, however given the choice of all three of the artefacts described here and in the last post, I would rather this one, as the detail of the casting is almost perfect. To reduce or even eliminate this artefact I would suggest the use of either wiring the mould together tightly, or using mechanical clamps to stop the mould from moving during the tapping and pouring process. I may even attempt to make some sort of mechanical tapping/shaking jig so as to reduce stresses on the soapstone mould as well as the chances of the mould moving.
In a happy coincidence when I was checking the email to confirm that I had gotten the commission done as requested, I noticed that I was missing a vital part of the Dragons. So the above information about the tapping/shaking process was only discovered after the wings were added, and the entire batch recast. I’m sure my customer will be much happier with the better detailed casts than he might have been with the previous batch, specially as his Dragons are now actually dragons and not Lizards.
* The “Button” is the larger opening in the mould where you pour the molten pewter. It usually gets cut off and recycled.
Posted in: Casters Note's
Tags: sveinn
October 9th, 2009 / No Comments » / by Sveinn inn kyrri Grimsson
It’s about time I got back to some real Pewter casting and the reporting of, so here’s my latest. I have recently been working on a token commission and actually paid attention to the detail of the results of the castings this time, so I thought I would write about it in an effort to further muddle it through in my mind as well as help the one or two of you out there.
When casting there are two main problems that cause artefacts on the cast item. The first is air pockets, and the second is pewter shrinkage due to the freezing process. Unfortunately in period soapstone casting, the solution to one of these problems is also what causes the other, and a balancing act needs to take place to minimise both effects.
Air pockets can be caused by two reasons that I have been able to work out, though I believe the second is another issue which can be fixed separately*. The first is a lack of air escaping the mould before the molten pewter freezes, either by air flow dynamics causing restrictions in air flow out of the mould as the molten pewter enters, or the pewter freezing before it gets a chance to fill all of the detail. This can be minimised by using a hot mould that allows the pewter to run into all detailed parts of the mould before it freezes, you may need to still play with the air flow dynamics on some moulds to ensure that the pressure of the liquid pewter entering the mould isn’t causing an air pocket in the mould to be trapped.
The secondary artefacts created when the molten pewter freezes and shrinks is a little harder to control, as the easiest way to control that is to have a cold mold and a quick pour of the molten pewter into the mould. The cold mold freezes a skin of pewter allowing the detail to remain. Freezing the pewter from the outside just a touch faster than it would with a hot mould this allow a harder skin to retain the detail whilst the pewter freezes and shrinks. Another way to stop the shrinking from effecting your finished casting is to have a large enough sprue connecting the pouring button with the cast product so that there is enough room for the shrinking pewter to pull down more molten pewter from the button, however this is not always easily possible, as this sprue needs to large enough to allow the sides to freeze before the centre.
Another method of minimising the effect of shrinking on the casting is to rapidly tap the mould on a wooden surface as you are pouring the pewter. This has the effect of increasing the pressure in the mould and effectively hammering the molten pewter into the details. It needs to be done as you are pouring, and you need to be very careful as you don’t want to move the mould parts, or splatter molten pewter.
These details leave me with the conclusion that in order to get a perfect casting each time from a gravity fed, non-pressurised soapstone mould casting there needs to be a very delicate balance between the temperature of the soapstone mould and the temperature of the molten pewter. If I were more serious about this process I would attempt to investigate this further with more period techniques for estimating the temperature of both mould and metal, however I believe that knowing that the balance exists and some means of minimising it’s effects are enough for me to continue. The art of getting a perfect casting from each pour is one that whilst very rewarding, is not necessary with the ease of turning out pewter castings it is often better to do the best you can, and recast the ones that don’t work. Of course, if it’s the techniques that are causing the artefacts in the first place, then these techniques do need to be addressed.
*The second cause is moisture in the soapstone turning into steam when contacting molten pewter. This is easily identifiable as it looks like shiny inverted bubbles on the surface of the pewter casting. It is also easy to avoid by pre-warming your mould before casting in an oven, however I find the easiest method is to just heat the mould over the heat source for melting your pewter, and then just keep casting in quick succession until it stops.
Posted in: Casters Note's
Tags: observations, sveinn
