Monday, October 21, 2013

Backyard Casting

I like to keep a camera handy in case I see or do something interesting.  This weekend the RoadQueen was hanging out and she was excited when I suggested we take advantage of a sunny but cool autumn afternoon and engage in a little backyard casting operation.  She is a naturally curious person and firearms enthusiast to boot so I was more than happy to demonstrate this cool process for her.

In the course of my bicycle commuting and recreational road riding I have trained myself to watch for wheel weights cast off from automobile wheels along the streets and roadways surrounding my home.  These weights are made out of a lead alloy and are clipped to the rim of a car wheel to balance out the spin of the wheel and prevent vibrations at speed.  The small steel clip eventually loosens and the weights pop loose. I often find them lying alongside the road near railroad crossings and around intersections.  Any place the car is likely to hit bumps in the road these weights can be found.  I also have a theory that that a loose weight can be released from a rim by an under-inflated tire rolling during a turn and pushing off the weight.

Over the course of a year I find two or three a month.  Earlier this summer I lucked out and found two on the same commute.  The two weights were just a few feet apart.

Once I've collected up a few I'll put them in a cast iron pot and warm on my Coleman camp stove.  The melting point of lead is 621.5 degrees F or 327.5 C so it is fairly easy to get a hot enough temperature to melt this dense, heavy metal.  In the picture above you can see a couple of the weights just turning to liquid.  As the lead melts I can remove and discard the steel clips from the pot.

I have found that my cast iron patio wood burner makes an excellent crucible to do the actual casting work.  Using the rim of the wood burner's opening and a piece of fire wood as rest for my ladle and mold I have a sheltered work area that is easy to keep at a constant high temperature.  

The trick to casting is to keep the mold blocks in the perfect temperature window of not too cool and not to hot.  If the mold is too cool the molten lead will start to harden as it is being poured into the mold and not fill the cavity completely.  If the mold is too hot the ball will remain in liquid form and deform itself as it rolls out of the mold when the halves of the block separate.  When the temperature is just right the ball will harden and drop out perfect.  Doing the work as shown inside the mouth of the wood burner where a high temperature can be maintained makes the process flow smooth and trouble free. 

Over the course of the afternoon we produced 53 .54 caliber round balls from the wheel weights I scrounged from the roadways around my home.

So what do I do with these little silver spheres you ask?  Why shoot them out of my walnut stocked Rocky Mountain Hawken Rifle of course.

This afternoon I chose 10 pieces in a blind sample from the production run to check the weight of the balls using an accurate beam scale.  Here are the results measured in grains:


The maximum spread between these 10 sample is 3 grains.  Not much!  

1 ounce = 437.5 grains
1 gram = 15.43 grains


  1. I don't recall EVER seeing wheel weights on my commutes, though I saw a Swiss Army Knife once.

    1. Nice find with the Swiss Army Steve. All I've found is few odd tools mostly wrenches and screwdrivers. I did pass a carpenter's level out in the country one time. I was miles from home and didn't feel like carrying a 5' level so I never stopped for it. Keep watching for the wheel weights, I bet you see one sooner or later.

  2. You have to calibrate your mental scanner to a given object to find it. I tend to find lots of hats, bike gloves, tire levers and other bike tools, and busted blinkers.

    Good to know you're all ready for the Zombie Apocalypse.

    1. Yes you're correct about the mental calibration Dave. I surprise myself often when I am traveling at speed and think I've spotted a weight. When I backtrack sure enough I find it laying in the road. It's much harder to see them while going faster but I guess it is the slight crescent shape and dull gray against the texture of the pavement that catches the eye.

      Mostly I notice them while I'm stopped at red lights and railroad crossings waiting for a passing train.

  3. Have I mentioned you are a renaissance man? Very cool! I have a bullet mold for my 1860 colt, I'd love to give this a try sometime. Excellent post!

    1. Yeah you have mentioned that. Thanks! I appreciate it. Variety is the spice of life you know. I like to try different stuff. It keeps things interesting.

      Give it a try for sure it is really easy and you will learn as you go. Make sure you have some good work gloves or welders gloves.

    2. Great article. A point to mention is that wheel weights are too hard. Pure lead is preferred for ML projectiles.

  4. Excellent shot... or the worlds crappiest ball bearings. :)