How To Build An Epoxy Resin Casting Mold

Resin Technical Center

How To Build An Epoxy Resin Casting Mold

How To Build An Epoxy Resin Casting Mold : MATERIAL USED FOR THE MOLD:

Building an epoxy resin casting mold is a very important step when creating a river table or other casting projects.

Some materials demonstrate superior insulating qualities than others. The material used to make the mold is important. Melamine, wood, polyurethane and silicone demonstrate good up to high insulation capacities, so can increase the exothermic effect. HDPE – High Density polyethylene can also be use to create a mold. The HDPE will create a better and cleaner surface compare to melamine and tape. Epoxy will not adhere to HDPE, therefore you won’t need to apply tape.

Choose Your Materials Wisely

As you may know epoxy will stick to many materials and surfaces. Among them, we include:

The cheapest and most accessible material is  melamine,  Medium Density Fiber, or plywood for the base and walls. AVOID: The metal demonstrates great heat dissipation ( Heat Sink) capacity which will greatly slow down the exothermic effect and directly the polymerization time. The metal will absorb a certain amount of heat required to cure the epoxy. Only extremely reactive epoxy systems need to be slowdown using a metal mold, meaning the epoxy solution is not adapted for this application.

REMEMBER : The epoxy solution should be working for you and not the opposite by adding extra work or costs. Using the right product for the right application is the only way to achieve better long lasting results.

Prevent The Epoxy From Sticking To Your Mold

It is essential to fill all inserts and mold cavities with “Tuck Tape” or “Tyvek” tapes to prevent leaks. Covering the bottom and walls of the mold with Polypropylene film will help prevent the epoxy from sticking to the mold and allow an easy removal of your river table or other epoxy project once the resin is fully cured.


How to seal your mold

Make sure the mold is free of dust and contaminants before sealing the bottom and edges. Use an air rifle as well as a clean cloth soaked in Isopropyl alcohol to clean the surface as well as to remove dust in the mould. All along the interior joints of the mould, apply a bead of silicone to seal the 90 degree angles to ensure that the epoxy will not seep outside of the mould. Make sure to wait 24 hours before proceeding to the next step.
Additional Tips: To add an extra layer of protection and stop any leaks, consider adding a line of silicone to the outsides of the mould.
In order to complete a project successfully, it is important to properly level your mold. Once the mold is level the epoxy will be able to level more easily.

Ready to pour your Epoxy

Then you can add your piece of wood or recessed element into the mold cavity. Be sure to stabilize your project to prevent it from floating when pouring. Use several blocks of wood covered with Tuck Tape or Tyvek tape throughout the project and then stabilize these using clamps.
It is important that your wood plank be as straight as possible to avoid movement.

Feel free to contact us if you have any questions or need guidance building your form at