Saturday, 31 March 2018

Playing with Pewter

At The Bushcraft Magazine  2017 Mayday Meet I was rather taken with attending a very popular pewter workshop that a chap called Allan Course was running, with the above bat and sprue (pouring spout) being the result. There's something rather elegant about pewter to my eye and indeed I could have paid extra to have some whitesmithing done on this bespoke US tomahawk of mine.

Now I've had this bat pinned up on a cork board in my garage since I made it, simply adding it onto my to do list, and with the snow having a final wintry fling  I decided a session with it was apt and hunkered down with it.  The patterning is different on the wings because Allan's first effort at casting it failed as the pewter poured out of the mold which he attributed to one of the wings not being deep enough. He quickly excavated it to make it deeper and it worked.

I decided to leave the sprue on as a handle to hold whilst I started the initial sanding with a metal file. I did this over a sheet of A4 to catch the shavings.

Pewter is quite soft so I made decent headway quite quickly. Not only was I looking to get the bat uniform, I also had to work on the size of the wings with one being larger than the other.

I removed the sprue once I felt that the shape was right and I utilised an origami container to keep the sprue, and shavings, in as I reckoned that there would be enough for me to have a crack at a second homemade casting. I weighed the off cuts which came in at 7g and the bat was marginally heavier at 8g so I reckoned I was on for another go.

And to finer sanding. I didn't save these shavings as they would be contaminated with the sandpaper dust. With the sprue gone I placed it on a small offcut of wood to make the job easier. I could have sanded it to a fine finish but I was aware that the wings were getting rather thin so I called it a day. Job done.

I filed a Cuttlefish from the pet shop smooth and cut it into two fairly similar sized pieces. I then drew the bat outline and looked for a suitable circular shape to fashion my pewter mold on. I did a rough add up of how many squares the bat covered and found that my wife's wedding ring was about right.

Actually the ring worked well as I pushed it halfway into one Cuttlefish pieces and then applied the other piece and pressed.


whilst together I sanded the base flat and level, carved three lines in for orientation and then extricated the ring. Allan issued everyone with a nail but I got a selection of screwdrivers.

Having pushed the ring half way into each part it made the perfect depth guide to scrape out the flesh evenly to. 

Once I'd done one half I sanded it smooth by blu tacking a disc of fine wet and dry paper onto the end of a lidded marker pen and abraded it with a gentle circular motion.

I was planning on carving a loop for a chain to go through but having had the flash of inspiration to use the sanding disc I opted to experiment by using a cocktail stick pushed through near one edge. I elected to make it on one side so's not to interrupt the impending flow of pewter. 

I made a hole in one side with the piece you see above, then broke a very small piece and inserted it into the hole, after that I put the two pieces together so that both sides were marked. With that done I hollowed out the two channels.

I decided on a simple design of a sun on one side and stars (formed with a torx head screwdriver) on the other.

Once a small sprue was added I found that the two pieces married up quite well by using the smoothed bases and guide lines.

I then introduced a full cocktail stick into the channels I made earlier. and then secured the mold with two tight elastic band wrappings so that I didn't have leakage like my bat one.

I made up my honey stove to accommodate some charcoal briquettes and got them fired up to receive my coke can crucible.

Once the briquettes had turned mainly grey I added another row and placed my impromptu crucible atop them. Imagine my surprise and delight to see a tiny dribble of mercury-like pewter melted in the bottom of the can which appeared to have been the sprue having succumbed. Frustratingly however the smaller shavings held out and I guess this must have just been down to a hot spot at the front so I awaited the rest of the shavings to catch up.

Sadly, in what seemed just the blink of an eye, the aluminium can also melted! To be fair there was a beautiful Red Kite overhead catching the sunlight which distracted me but my pewter had now largely disappeared (although it had melted). I salvaged a small amount but it was only a token scraping.

I'd hoped to birth a flesh of my flesh relation of the bat but as I'd made the mould and had a tiny bit of the original pewter left I decided to invest  in some more. I ordered 50g of 'shredded' pewter grain rather than an ingot from Sheffield Metal Findings and can thoroughly recommend them for their communications, speedy delivery and product.

So out came the honey stove again and this time I had a more robust bamboo shoot tin which, like the coke can, I gently squashed so that a pouring spout formed. The grains melted really quickly but one thing I overlooked was that there was a lining in the tin which burnt off and I had to try and coax it away from the molten pewter. the bit I'd saved may well have been a mix of pewter and aluminium because it didn't reduce much.

I'd secured the mold in a clamp to make the pouring process hands free  and so that I could give the cocktail stick the smallest of gentle twists to hopefully facilitate a smooth withdrawal. To be honest I was so focused on a successful pour that I didn't get to touch the cocktail stick. Whether the stick was welded to the pewter was immaterial at the moment because I was just pleased to have hopefully achieved a successful cast.

Phew, I had birthed a small pendant. I was eager to remove it but it was still a little bit warm. After a bit of cajoling the cocktail stick came out. With the three part process of getting the stick in it wasn't a 100% tight fit so there had been a bit of leakage which wasn't easy to clean up. 

The pendant was a vaguely yellow colour which I've abraded off as best I can, a bit hard given the small and fiddly patterning, and I've assumed that it was in part due to contamination from the tin can lining. I've burned the can after finishing to fully clear it up for another attempt at some stage.