Intro: Got It Wrong on an Aluminum Melt
Everybody shows how easy it is to pour aluminum... Check youtube, I will wait... Try the Anthill pours for example...
Too slow, too fast, wrong heat, wrong materials, sun goes behind a cloud, who knows, it just didn't work even after all the prep...
The fail here is both a void which looks like a crack and a slump near the vent edge of the pour.
OK so the crack looks real cool, almost like an ancient mistake. I like it and am having a hard time destroying the piece by remelting...
Step 1: Make the Mould
Dry sand casting is perhaps the simplest of casting. when it works, it works well, when it doesn't, well you will just have to remelt and start again.
I spent several minutes getting this form in foam just right. I made precision cuts with the lathe and made sure that there was ample vents for the foam gas to escape during the pour.
The final shape was an envisioned perfection of form and function...
Step 2: Bury It in Sand
Lost foam casting means that you will take a foam structure, bury it in sand pour hot metal over it and pray for the metal to take the form left by the foam as it melts under tremendous heat.
I took the foam structure then buried it in dry sand with the foam sprue in a metal receiving cup and vent showing on the top of the sand
Step 3: MELT...
I used scrap aluminum from many sources and added borax and washing soda for flux. all is great and I am happy so far.
Step 4: Pour
The molten metal is then poured into the receiving cup at a steady rate until it flows freely from the vent foam section.
Keep water nearby to quench any overflow.
They don't tell you but the burned foam stinks! really bad!! I'm serious, it's awful!!! The sand will stink for many months afterward as well.
Despite the rank nature of the foam, so far it looks great.
Step 5: AND... FAIL!!!
Form secure... Check!
Molten metal... Check!
Flux added... Check!
Dross removed... Check!
Safety equipment worn... Check!
Steady pour... Check!
Wait for cooling... Check!
Remove from Sand... Check!
Flawless form... FAIL!!!
Now we start again! But I like the nature of the fail and will definitely keep this one as a conversation piece. Stop by my garage and I will show it to you...