First Attempt At Creating Sand Molds

So the time came to try and create an actual sand mold. There where too many variables and unknowns in this attempt, and ultimately was a failure. We learned a lot though and our next attempt was MUCH better.

In this attempt we are trying to replicate a framing triangle (hopefully to get a good feel on actual metal shrinkage), a drama face mask from a small clear plastic mold for play-doh, two emblems made of sculpey clay, a gear, and a coin. The plan was to create a gate through the molds and get all 4 pieces from a single mold.

Where we failed was assuming we could make a 2 part mold pattern from single part patterns. These kind of objects MUST be 2 part patterns so that the cope and drag both have flat tops that can be fitted together.

First the objects are placed in the bottom of the flask

Placement of the spaceholder for the sprue

Pack some sand around that sprue 

Add sand through filter to break up chunks

Cover the parts with fine sand 

Beat the shit out of the mold at every chance 

To aid my beating I made this block of steel reinforced wood, covered in duct tape. 

Using a palm nailer and beatblock to emulate a shake/jolt machine.

Remove the spacers for the sprues. 

Scrape the top level 

It's half of a mold!

This is where I should have stopped. I should have cut the gates in this sand, removed the patterns, and just made the backs flat. This would have probably done me better than the inevitable failure to come.

Coating the top of the patterns with parting poweder (talc or baking powder) to make them separate easier. Also realizing I forgot to cover the other side of the patterns. Doh

Use a brush to get it everywhere.

Throw on the top of the flask.

At this point I should have a completely flat mold. I should now be fitting the other half of the patterns to their mates, adding parting powder, and then doing it again. This would allow them to be reseperated without damaging the mold.  Instead I just added the back of the objects in sand, and when I removed the top of the flask again the patterns fell out and damaged both sides of the mold. At this point I gave up the ghost for the day and went back to considering ways of making patterns.

On a plus note, the level of detail we got in the sand was ASTOUNDING!