Once you are done sculpting your form you need to bury it in sand with the attached foam pour cup sticking out of the top of the sand bed. For this we used metal garbage cans and sloped the top layer of the sand downwards towards the form to prevent metal from flowing out of the garbage can. Be sure to also pack the sand in as tightly as possible in and around the form without messing up of destroying your form in the process. Once that is done create holes connecting to the form to serve as makeshift sprues for the trapped air created by the disintegrating Styrofoam.
.Note: Be sure to allow for the overflow of metal by creating channels in the sand and to not create too large of a form as this method works best on smaller forms
The image above shows the foam forms buried and packed in sand pre-pour with the foam gates sticking out of the sand. The image to the left is a post pour pick with some of the foam forms uncovered. For this pour we used aluminum.
Embedding the Form in Sand