Difference between revisions of "Aluminum Recycling"

Revision as of 17:01, 23 June 2010

User tip#1 (using old soda cans)

• Collect your cans, the more the better

• Cut the tops and bottoms off. For instance use shears or scissors. You want to seperate the cans into 3 sections. The tops, sides, and bottoms. The side when cut, looks like a thin single sheet.

• Drop them all into boiling water and boil for a few minutes. This helps by cleaning and removing any varnish and soda left in the can. It also helps by removing/washing any sand/dust that tends to collect in a can left laying around or "donated". Let air dry.

• The bottoms have the most metal and can be stacked one on top of each other. Like the fake potato chips that come in a can.

This reduces the surface area quite a bit. When it begins to melt, the bottom forms a pool that gravity pulls the stack into the melt pool. Your dross will be minimal. I have used no flux, borax, wood ash, charcoal ash, pure carbon from a oxy/acety torch, etc as covers.

• When I started I made my own flux from Borax brand melted in a crucible till it goes 'glassy' and then crushing it. It was easier to

buy some from a supplier later.

• Now take a washed side and roll it into a tight cylinder, then add another, etc until you have a nice thick solid roll of sides and tie off with aluminum wire to keep it together. Add that to the melt.

• I don't usually bother with the tops, other than submerging them one at a time until they melt. It's usually too time consuming.

• Nice clean skin with very little dross and I get about 75-80 percent conversion into ingots.

• I use old quart cast iron pots as crucibles. The one with lids can be drilled to make pouring easy, and they skim the pour very nicely.

• Just before pouring I stick in a steel rod and stir it a bit. This helps to get rid of any bubbles.

User tip #2 (Using old Aluminum wheels)

Wheelium is often Al-357(?), which is excellent for casting stress parts and machines well.

HOWEVER, some wheels contain Mg in their alloy and that presents problems of explosion, flammability and reaction with a steel crucible. You must test the wheel alloy....BEFORE... you try to melt it in the furnace.

Checking for magnesium #1

Take a little chunk of the alloy and torch it with a hand-held propane torch. Look for brilliant white flame / sparks. If, present, there's Mg present, so find another source.

Checking for magnesium #2

I find the easiest sure method is to scrape off some filings or small chips, - if it melts with a propane torch then its aluminum if it flares its probably mg or alloy with mg.

Misc

Wheels are a great source and are probably in most cases 356A alloy, great for casting and machining. Cans are also good when zinc and copper are added to make ZA-? alloys.
Some see recycle as something lower on their list of 'to-do's' but any form of aluminum can be melted and made useful with just a bit of study and adding the correct materials! Wheels can be broken into smaller pieces suitable for the crucible by a methos of 'hot short' which means roasting over a fire until at the stage of crumbly like a fresh cookie