Sunday 17 May 2015

Thing of the week - Casting Tools.


Hey everybody what is going on?
I'm Roger in Technology and this is a quick project update on the Foundry.

Since I want to cast some bronze, I've got to make some tools on a budget. The bucket foundry cost next to nothing, is lightweight, completely portable, clean-burning and far exceeds a thousand degrees. So far my efforts have been met with nothing but success I'm staring down the barrel of two significant purchases.

Metal Ingots
The first is the metal stock. Copper and Tin ingots can be bought, and are going to cost around £30 per kilo including postage, I think tin is more than that. I'll shop around and get slightly cheaper but that's the ballpark. I'm going to need one tin ingot, and I guess that means ten copper ones but I'm reluctant to make eleven kilos of bronze. It feels like a lot for the small projects I've got in mind.
Buying copper in smaller (than 10kg) quantities is more expensive, and the cheapest option is about ten kilos of copper and one of tin - but that's around a £300 materials cost. I guess I could soak up the cost but its a huge outlay this early on.

Recycling aluminium drinks cans is a good idea. It'll continue the thrift-shop philosophy I've adopted so far and allow me to make a casting flask, practice to process, learn how to make casting sand and generally run the whole process start to finish before I start ruining home-made bronze.

Anvil
Astute observers will notice that I haven't talked much about anvils. Until I have a forgehouse built, there is nowhere to put an anvil but I'm not going to be able to work steel, or even work harden bronze, without one.  The anvil is a versatile tool that so much smithing relies on.

An affordable cast iron anvil just isn't worth owning, you can buy cast anvil on amazon for fifty quid but they look terrible and frankly thats a lot of money for something thats just going to be used as a doorstop.
I've found a wide faced farriers anvil for £450 that looks perfect. But this alone costs more than I want to spend and it'd be a shame to come this far only to divert all my budget into a block of steel - no matter how fancy.
To this end I've managed to get a sledge hammer, its light - only 7lb - but once set into a block it'll give me a hard enough surface to make a few small tools and to work harden bronze on. I could buy a 14lb hammer very cheaply, but the 7lb head is light enough that I may actually use it later on so there should be no waste.
I'm going to back this up with a granite block from the garden centre. Its not too costly and will be equal or better than what was available to my bronze age predecessor. It'll probably be fine for work hardening bronze on, and in combination with the sledge head I think I'll do fine.

Crucible Tongs and other casting tools.
I've bought screws and some timber to make a flask, a couple of clamps and some more sandpaper. The costs there are low but mounting up and I do want to keep an eye on the spend. My makeshift hammer-anvil will be sufficient to make some tongs, and with those I'll be able to make some crucible tongs, a ram, rap and all some other trinkets for casting.  The overall cost here is very little. I could use scrap steel, and I've got a couple of mild steel bars including my thermometer that I could turn into tongs.

Lastly, I've spent some time carving a couple of patterns to cast. This was done with some timber and a stanley knife, and then 60 grit paper.  I can see myself making a steel whittling knife as a very early project once I start working steel because this was a lot of fun.
The most interesting of these is a pattern for a bronze dagger. Its in the style of a bronze age Wilberton, just a smaller blade - probably about ten inch. This was cut from cheap timber and is about the shape I wanted but I don't think I've left enough excess for shrinkage and finishing so the end product might be a bit small.
When I scale up, I'll probably try a full size Wilberton, or a Ewart Park style sword which I can cast and finish in bronze.

I've started carving a wooden ram and rap, and I'll be collecting aluminium this week.  I also need to carve some ingot casts for excess material but after that I'm ready to run through the whole process with my wilberton style dagger in aluminium.

That's a roundup of the project status, and my thoughts on tools and materials. I'm also arranging to borrow a video camera so should be able to start videoing the process from here on in.

If you have any questions on metal work, wood carving, or smithing then leave a comment. I'm not staying a hundred percent authentic to traditional methods, but everything I'm doing is with simple tools available to the everyman.

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