If you have a flat, fragile part that needs to be secured against breaking, there’s a way to make it tougher. Today we’ll show you how to harden a model using resin and glass mat.

Be sure to check out the previous episode where we soldered rivet nuts into 3D printed objects: Episode 02


Necessary Tools


Prepare: a can of polyester resin, a hardener that should come in the same box, textile glass mat, a container to mix the ingredients, a paintbrush and scissors.


Cutting the Mat

Cut the proper shape from the mat. The piece should be a little bigger than the part it will cover.

Before you apply the resin, you need to clean the surface of the model and smooth it with sandpaper. You should also apply some degreaser to it.

Mixing the Ingredients

Mix the resin with the hardener. Use 100 grams of the resin for every 2 or 3 grams of the hardener.

The pot life for this mixture is 10 to 15 minutes so don’t wait too long.

Applying the Resin

Put the first layer of the resin onto the whole surface you want to harden. Stick the mat to the model and apply another layer of the resin so that it soaks through the mat.


Cutting the Excess Material

Cut the excess material. Leave the model to dry for about 45 minutes in 20°C.

The part you hardened can be further sanded, primed and painted.

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