Dog’s Head: Aluminium Furnace


The missing bit in my attempts to cast an aluminium dog’s head – melting aluminium.

First Plan

Make a gas or charcoal powered furnace: youtube video by Grant Thompson which set this idea off.

The problem with gas and charcoal (+hairdryer) are they are noisy, seem a little hit-and-miss & inconvenient and are just too ‘fiery’ for me.

Current Plan

I came across this guy TAOW who made an electronic foundry, and that is the way I have gone.

Shopping List

My design is based on the design by TAOW.

Electronics

Aliexpress shopping list as follows

  1. Heating coil (NZ$3-4) 2200W so 10A at 220V. Says its FeCrAl (Kanthal), but who knows.
  2. Fire-retardant wire (NZ$ 7-8  for 5m….I needed <  1 m). I put a blowtorch to it and it is fire-retardant. I learn my lesson already on selecting wire gauge appropriate to your current.
  3. PID and Solid State Relay. (~ NZ$20). Also came with a K-thermocouple but…
  4. I got another thermocouple (~NZ$5) with a longer prober and higher temp range. Which I just noticed was from the “Relax Yourselves Store

Hardware

  1. I went to a demolition yard for the refractory bricks. Two-bucks-a-piece. They were salvaged from a *PROPER* foundry.
  2. A tub of refractory cement and a bag of silica sand (to bulk cement out a bit since it cost more than gold).
  3. Various scraps of steel for the frame.
  4. An old metal toolbox I picked up in a charity store to contain all the electronics.
  5. Some car engine enamel spray paint to tidy things up and hide my shitty welds

My control box. A repurposed charity shop toolbox. PID on top showing current temperature (24C) and set temp (150C). Am testing it all works using the oven. Chicken Kievs.

Adjustments

…to TAOW’s design:

  • Ceramic shield. Sounds way more high-tech than it is. Sounds like something on the noise of the space shuttle – actually something built from bathroom tiles:
    • Separates the electricity from the crucible and …..er… you. This seems to be a major design flaw to TAOW’s design…one that may well be his demise.
    • Is a replaceable/ maintainable cassette design with the heating element arranged so the two terminals protrude vertically from the base.
  • DIY Crucible and tongs (I got a MIG welder!). I have just gone with a thick-walled steel crucible made from salvaged steel tube.

 

 

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