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Casting aluminum in sand



Gadget
02-01-2010, 04:55 PM
I have had some questions on the sand casting process here so I took some photos of the process to help demonstrate how it's done.

Photo 1 is the two piece pattern.
Photo 2 is the first half in the cope ready to add sand. (sand box half)
Photo 3 is the same pattern half after adding sand (split half view)
Photo 4 is the second half of the pattern locked on the first half embedded in the sand.
Photo 5 is the two pattern halves embedded in the two piece sand box (called flask)
More on next link.

Gadget
02-01-2010, 05:01 PM
Photo 6 shows the draw pins (screws) and pouring gate cut in the mold.
Photo 7 is the sand cavity after pulling the pattern out of the cope.
Photo 8 is the sand cavity after pulling the second half pattern out of the drag.
Photo 9 is the casting with the gate and pouring sprue still attached.
Photo 10 is the casting with the gate cut off.

arandall
02-01-2010, 06:19 PM
Gadget:
Where the h-- do you learn all this stuff?

Cheers,
Art R.

Gadget
02-01-2010, 06:38 PM
I got the basics of sand casting in high school but learned the finer details from the Gingery books on foundry and the machine projects years ago.

matteh99
02-01-2010, 09:27 PM
What are the patterns made of? I was expecting wood but they don't look like wood.

Eric

KHK
02-01-2010, 09:45 PM
I learn something every day!! Thanks Gadget

Hamstn
02-02-2010, 06:41 AM
I was one that asked the question. Now things are much more clear. Thanks for the detailed post.

Gadget
02-02-2010, 05:43 PM
What are the patterns made of? I was expecting wood but they don't look like wood.

Eric

The patterns are wood but are painted with a thick latex paint to prevent moisture absorption from the sand.

bbiggs
02-03-2010, 07:00 PM
I too like those Gingery books.

Once neede a one off cast aluminum part to repair a commercial laundry extractor for a friend.

Made the form from the green styrafoam looking plastic that florists use.

Just put in a cope made from 2x6s and plywood, tamped casting sand around it and put 2 sprus, one to pour, one to let gas escape.

Made a ladle from a piece of pipe and used an old electric kiln to melt the aluminum

Worked great, guess you could call it the lost foam method.

Bill

Gadget
02-03-2010, 07:11 PM
I'm working on a lost foam pattern for a blower right now. I have the drawing but need to get the program to convert it to Gcode for my CNC router to cut it.

bbiggs
02-03-2010, 08:30 PM
What type foam are you using? The green florist foam was pretty open cell and the surface was somewhat rough.

Sure was easy to work with

I was real leery of an explosion with the hot aluminum hitting the foam so did some small scale tests. Was not an issue at all

Bill

Gadget
02-03-2010, 08:34 PM
The insulation foam is very close cells and makes a good pattern. I have some white but green and red are also used. These are all very small closed cell material.
You can do a youtube search for lost foam casting and find quite a few videos on the process.