Great article, I love his detailed explanations of <i>why</i> he does things the way he does them (the boots without laces, the natural fibers) when it comes to safety.<p>Don't be fooled by the low-tech appearance, this guy is top notch, he's been doing a ton of research and has quite a bit of experience. You don't set this up the first time out of the gate like this and if you plan on doing any aluminum casting yourself this would be a great starting point.<p>I also like how he evaluates what he's done, notices what could be improved and makes notes to do those things better next time. That's how you get to where he's gotten in the first place. There are other aluminum melting tutorials out there that make me cringe.<p>If anybody is wondering why concrete can explode when heated rapidly, concrete will always contain a percentage of water and when you heat that up faster than the steam can escape from the material it will cause a steam explosion.
This is an excellent article, and shows why you need to do all the fussy finicky things that you need to.<p>It touches on two stories of personal interest to me. First, my maternal grandfather spent a fair amount of his time in a silver mine in the blacksmith shop. This was a small enough mine that mining was done with picks, shovels and the like. They would wear out, and need to go to the blacksmith shop to be refurbished. We had an old open coal forge that had been used by the previous owner sitting unused in one of our sheds. Grandpa came by one day to fix up one of his pickaxes. The forge had a blower powered by a hand crank. He first scooped the coal out from the hole in the middle of the bottom of the body of the forge. Then took a coffee can, placed it over the hole, and packed coal around the can, and sprayed water on it. He had me turn the crank as he lit the coal, gently at first, then stronger.<p>Once the heat was up, he began heating the tip of the axe. As he heated, he told stories of how you heat, then cool the tool. Too much heat could burn the tool. And when to take it out to shape the tool on the anvil. And how there was different types of quenching--water, oil. Depending on what the tool was to be used for.<p>The other story is that my brother (now retired) was a professional welder and instrument maker. He made instruments for telescopes. As a gift, he once gave me a pair of dice made of aluminum. Not particularly fancy, but he noted that the trick with aluminum is that it will suddenly melt on you without turning red.
Of course, having a bucket of sand handy to put fires out does raise the question as to what would make the sand burn (at least if you are in the habit of reading <i>Things I Won't Work With</i>):<p><a href="http://pipeline.corante.com/archives/2008/02/26/sand_wont_save_you_this_time.php" rel="nofollow">http://pipeline.corante.com/archives/2008/02/26/sand_wont_sa...</a>
Lionel Oliver has put together a great resource for this kind of thing for others who are interested [1]. When I was in high school I built a foundry (basically a stack of bricks with a draft hole and a place to put a small cast iron pot). I used it to melt aluminum and make castings in sand, and it was tons of fun. Looking back, I had no concept of safety at all but amazingly I didn't burn down our chicken coop, which is where it was built. The fuel I used to melt the aluminum was leftover lumber from our house remodel that I cut into cubes, and I had an old double squirrel cage blower set up to provide the draft.<p>1. backyardmetalcasting.com
That reminds me of the legendary Nils Provos and his blacksmithing ambitions: <a href="http://www.wired.com/2013/02/provos/" rel="nofollow">http://www.wired.com/2013/02/provos/</a><p>His videos: <a href="https://www.youtube.com/user/mintwart" rel="nofollow">https://www.youtube.com/user/mintwart</a>
If people find this interesting they might also like the myfordboy channel on youtube: <a href="https://www.youtube.com/user/myfordboy" rel="nofollow">https://www.youtube.com/user/myfordboy</a><p>There's tons of material in there on machining and especially metal casting at home.
Nice article. As an unsafe counter-point, a few years ago I came home to my (then) 16 year-old son in the backyard tending to a pit he'd dug, full of a blazing stack of sticks that he was stoking with my leaf blower... sparks flying everywhere. He used this to first melt pennies, then my wife's aluminum cake pans. When I arrived he didn't have a shirt on, because he didn't want to burn his clothes. Ah, youth!
Just read the entire series (seems he was inspired in the summer of 2012, and recently returned to this backyard project). I found it really engrossing, and as he wrote in his first post, the spirit of hacking with tools outside the metaphorical software application.
Suggestion for next time - long sleeves. If a hot spatter lands on your arm, you could flinch and drop the crucible. And now you have a bigger problem.