Back Purge Silicone Bung Mould – 2.5in (63.5mm)

## Back Purge Silicone Bung Mould – 2.5in (63.5mm)

This is a reusable mould for casting a silicone back-purge bung sized for a 2.5" / 63.5 mm tube.

It allows you to inject liquid silicone into the cavity (via syringe) to create a flexible bung that seals the tube ID for argon back purging during TIG welding.

### Intended Use

- Cast a flexible purge bung to seal 2.5" (63.5 mm) tube

- Support cleaner internal welds by maintaining a back-purge atmosphere

### Material Compatibility

- Designed for A10 or A25 silicone (or equivalent low-durometer casting silicone)

### Basic Process (High Level)

1. Assemble/close the mould

2. Mix silicone per manufacturer instructions

3. Inject using a syringe until the cavity is full

4. Allow to cure, then demould and trim as needed

### Recommended Parts (Optional)

- 1 ml feeding syringe (for accurate, low-mess injection)

- PC4-M10 pneumatic connector (quick connection point)

### Links

• Feeding syringe (1 ml):

• PC4-M10 pneumatic connector:

• High-temperature silicone rubber kit (1 kg):