How to Prevent Bubbles in Resin Fishing Sinkers

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Bubbles are a common hurdle when casting resin fishing sinkers, but a few careful steps can help you create smooth, professional results every time. Here’s how to address and prevent unwanted bubbles.

Step-by-step bubble prevention

To minimise bubbles, begin by pouring your resin mixture very slowly into the mould. This helps air escape as the resin fills every detail. Once poured, gently tap or flex the silicone mould to encourage trapped bubbles to surface and pop naturally. If working with intricate shapes, using a toothpick or skewer can help prick visible air pockets.

Avoid stirring the resin excessively, as this introduces excess air.
Let the resin sit for a few minutes before pouring to allow bubbles to rise.
For best results, use a translucent mould like the “Pure Mould” Liquid Silicone Rubber – its clarity lets you easily spot and fix surface bubbles.

What to do if bubbles appear in your finished sinker

If you notice bubbles after demoulding, small surface blemishes can often be sanded away once fully cured. For larger internal pockets, consider remaking the sinker, focusing on slower pouring and increased tapping of the mould. Cooling the resin slightly before use can also help with degassing, but always follow your resin’s instructions.

When bubble control matters most

Bubbles can affect the sinker’s weight and durability, especially if the sinker is used repeatedly or exposed to water. Paying attention to your casting technique matters most for performance and a neat finish.

Related guides

How To Make Fishing Sinker Moulds With Resin

With some simple adjustments, you can reliably avoid bubbles and achieve polished results with your resin fishing sinker moulds. For further tips on successful sinker casting, see our main guide on how to make fishing sinker moulds with resin.