First aluminum melt: the $90 bucket furnace and what I would do differently
Build
Steel bucket, 2" of castable refractory (not just plaster and sand, that cracks and spalls), a 1" steel pipe tuyere angled tangentially, a hair dryer on a dimmer for air, and charcoal. Crucible: a cut-down steel fire extinguisher body with a welded bail. Lid: a paver with a 2" vent hole.
Melt
Preheat the furnace and the crucible before adding metal. Add clean aluminum (cast scrap like old pistons, lawnmower decks and heat sinks is better than cans; cans are mostly oxide and paint). Skim dross, pour into a muffin tin preheated on the lid for ingots.
Safety
Moisture is the enemy: a damp mold, a damp ingot mold, or a damp scoop will send molten metal back at you. Everything that touches the melt gets preheated. Leather, face shield, no synthetic clothes, pour over dry sand, never over concrete (it spalls and pops).
Differently
Buy a real clay-graphite crucible. The steel one worked for six melts, then iron contamination started showing up and it got thin. $35 well spent.
Materials
- steel bucket
- castable refractory (50 lb)
- 1" black pipe
- hair dryer + dimmer
- charcoal
- clay-graphite crucible (A3 or A4)
Tools
- angle grinder
- drill
- leather gloves, face shield, apron
- steel tongs and skimmer
#foundry#aluminum#melting#crucible#furnace#casting
7 comments
Log in or sign up to join the discussion.
Small addition: wear eye protection for the part where you pry it. Learned that one the hard way.
The "what went wrong" section is the most useful part of this. More people should do that.
Tried this over the weekend and it worked first time. Thanks for writing it up properly.
Unplug it. Always. Takes two seconds and the worst case otherwise is a trip to the ER.
Small addition: wear eye protection for the part where you pry it. Learned that one the hard way.
Can confirm, the cheap part is the one that fails. Replaced mine twice before reading this.
Tried this over the weekend and it worked first time. Thanks for writing it up properly.