Aluminum melty, from styrofoam to end result

TechNinja's picture

At long last the summer has given me another chance to redeem myself in aluminum (Why the summer.. when it would seem that copious amounts of heat and fire go better with winter).

Here I've finally documented almost the entire setup, from carving to placing in the sand, to pouring.. the only part I've left out is the finishing.. which really is just grinding and wire brushing.. not exactly prime time interesting...

I had a number more projects for this burn than the last.. and unfortunately raised the bar a little too high for one project: the Thing.

The idea was meant as a present for my Dad's birthday, but not for anything other than to try and do it. First a wide-ish base about the size of a good thin novel, two vertical stands that each hold two gears. those gears inter-mesh and allow you to turn the one on the far right side with a handle, to turn the furthest left gear, with something silly on it to spin (deely-bopper?)

During pour, the large mass of aluminum melted and caved in more than half of the structure before it set (not pictured). So sad! Also the multiple structure pour resulted in the two large gears for the thing melting and caving in before being set as well! Awful...

BUT! Sylvia's little guy, two gears and at least two things made by the D worked great! So not a total failure.

When I can, I'll add pictures of the finished (wire brushed) items, and the total monstrosity of a failure (it's like 4 pounds of aluminum).

The bottom of the "thing" with (over)complicated sprues protruding from the bottom
A chockload of styrofoam, harvested from my Dad's cave.. One or two boxes worth is all you need.
Gear 1 of 4, closeup. Using a stencil made in Inkscape, printed, cut-out then edged into the styrofoam
The Stencil and tools used to do the fine work. I don't have a wire foam cutter, but the tiny edge file and rasp worked great
I decided the best way to make two gears that will be guaranteed to fit together, is to make a thick one and cut it in half!
Sylvia, picture here using her Dad's sandpaper he got for his birthday. A semi-fine grit does an awesome job at shaping
I saved all my sprue work for on site (so they don't break off getting there) and it's always a good idea to size up your pours.
My youngest daughter now get's her name in aluminum! The red on the A is candle wax after a mishap with the knife...
The D goes in for the pour
Talulah's name right after 2 mins of cooling. Worried it might have leaked, we poured the sand off quickly. But, it worked great! Whew...
After a quick dip in the pond... With these pieces I'm always stuck wondering if I should saw off the sprues or not... they make such neat stands
Sylvia took this little guy from idea to drawing to this. All I had to do was dremel out eyes and the happy smile.
A monopoly piece drawn and for my mother in law. The smallest piece I'd ever attempted
The final four gears, with sprues in place ready to be placed under the sand
Sprues for the gears, dragonfly piece and Sylvia's little guy poke through the sand
The furnace.. she be a hot one...
Styrofoam smoke.. Don't breath that!
Right after pour.. and something is definitely wrong! The black edging shows that the sand got too hot and melted one of the sprues away from one of the gears, destroying it before the aluminum could touch it
From the remaininf blob, the only things that could be saved: The dragonfly without the base, the little guy perfect, and the two gears, also just fine