Reclaiming Usable Metals




About: I like to think of myself as a Renaissance Man... But I think I just have too much free time.

When you are working with metal, whether casting, on the lathe, or by hand you will get slag and flash. This is a simple way to reclaim those leftovers back into useable metals.

Step 1: This Is Slag

Slag is oxidized metal or impurities that must be scraped off the top of melted metals. If left in it is both unpleasant in appearance and can weaken the finished product significantly.

Step 2: Collect All of the Slag Into a Pile

Using an old stainless steel bowl or steel pie plate. Pile all of your slag into a loose pile.

Step 3: Borax

Add about two tablespoons of anhydrous borax into the mix with the slag. This will both lower the melting temperature of impurities (such as iron), accumulate much of the slag in a molten glass-like substance.

Step 4: Get Your Torch

I prefer to use MAPP (a fuel gas based on a stabilized mixture of methylacetylene aka propane and propadiene) you can also use propane alone but it will take longer since propane burns less hot.

--- Warnings ---
Please only allow adults to handle or use torches or open flames.
Do not try to use these products in bright direct sunlight, the flame is blue and is not visible in some conditions.
Use in a well ventilated area and have a CO detector.
Follow all safety instructions on the bottle / MSDS.

Step 5: Caution

Be careful as you begin to melt the borax, if you point the flame directly at it the borax will blow all over the room. Be prepared because it will happen some regardless but it's the difference between a little and almost all of it.

Step 6: Melt

As the borax begins to dissolve move in with the flame more. Get the entire pile to red hot.

Step 7: Shift It

Using stainless steel tongs carefully tip the plate to one side. Soon a small stream of metal will begin to run away from the slag.

Step 8: Finished

Carefully remove the leftover slag and allow it to cool before disposing of it. Pour the useable metal into a crucible or form to allow it to cool. You can then remelt and refine further if you wish.

This method has worked well for me in the past. It usually yields 4-6 ounces out of a pound of slag.

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    5 Discussions

    Captain Tight-Pants

    2 years ago

    Is there a better way to do this is you have pounds of slag from doing cans?

    I have actually used this with silver, zinc, tin, pewter, and aluminum. Aluminum produces ALOT of slag because there is plastic coating inside and out of most cans.


    4 years ago on Introduction

    Cool! Thanks for sharing. This 'ible could prove useful as my family has begun the process of making a mini foundry.

    1 reply