Troubleshooting guide

Why Masking Plugs Fall Out

Plug fallout is usually a fit and process issue, not only a material issue. Start by checking geometry and handling.

The plug may be undersized

Nominal hole size can differ from the actual part. Measure the real diameter and test adjacent sample sizes before assuming the product family is wrong.

Insertion depth may be too shallow

A plug that seats only at the edge can loosen during handling or thermal exposure. Check usable depth and whether the taper engages enough surface area.

The wrong geometry may be selected

A through hole with removal-speed issues may need a pull plug, while a hole plus contact face may need a flange or washer style instead of a plain tapered plug.

The process may expose the weakness

Rack movement, pre-treatment, air flow, bake cycle and removal method can all reveal a weak fit. Test samples in the actual workflow before bulk approval.

Ready to narrow the options?

Use samples to validate the final fit.

Include your process, product type, diameter, temperature, quantity and drawing, photo or current part number.