---
title: Make a box to cast your mould
slug: make-a-box-to-cast-your-mould
step: 3
howto: make-plaster-moulds-for-large-products
tags: ["product","injection","extrusion","mould"]
category: Moulds
difficulty: Medium
time: < 1 week
location: 
---
# Step 3: Make a box to cast your mould
Construct a box around your model, ensuring everything is sealed and secure to prevent it from floating when pouring the plaster. Melamine is an effective material for the box, though plywood is also suitable.

Consider using a mold release, such as petroleum jelly, to facilitate easier separation of the plaster mold.

Incorporating reference pins can be useful for aligning the molds accurately in future stages.
![IMG_3594.jpg](/resources/howtos/make-plaster-moulds-for-large-products/img_3594.jpg)
![IMG_3537.jpg](/resources/howtos/make-plaster-moulds-for-large-products/img_3537.jpg)
![IMG_3529.jpg](/resources/howtos/make-plaster-moulds-for-large-products/img_3529.jpg)