How to reliably restore damaged plastic gear teeth

Cut damaged teeth of a plastic gear can be restored independently without any special effort. No complex devices, tools or machines are needed for this. We will restore the gear using polymer compounds based on epoxy resin.

Let's move on to restoring the gear

The restoration operation begins with the removal of the damaged area. Considering that the part being repaired is made of soft plastic, this is not at all difficult to do. A regular knife will do the job. It's even better if you have a miniature drill with a cutting wheel.

Next, you need to make a mold to cast the damaged area. Regular paraffin from a household candle is perfect for this. To make the mold, we fix the gear on a flat surface. We fix it with a self-tapping screw. A piece of tin, for example, from a beer can, will serve as a limiter for casting. We install it on the entire side of the part using hot glue.

Heat the paraffin in a suitable container. To do this we use a hair dryer.Carefully pour the melt into the prepared mold. We distribute it evenly with a thin wire so that the paraffin penetrates inside the gear teeth. And wait for it to harden.

When the paraffin hardens, remove the tin, unscrew the gear from the surface and carefully remove excess paraffin from the part with a knife. We check the quality of the resulting casting - the teeth must be intact, the part fits correctly with the gear being restored.

Cooking epoxy composition. We apply it to the paraffin mold. We carefully and carefully ensure that the resin gets inside each tooth of our mold. Next, we connect the damaged gear with the paraffin matrix we made.

A few hours later, after the polymer has hardened, you should start finishing the restored part. It is done using sandpaper and an abrasive attachment on a microdrill.