Why Won’t My Glue Tabs Stick to the Panel?

One of the most common questions GPR technicians have is “why won’t my glue stick”. Following our 6C process ensures optimal adhesion every time and can resolve most common issues. Here are a few of the most common reasons for glue not sticking and how to fix them.

Contaminated Panel

Contaminates on the surface of a panel or tab can prevent proper adhesion and limit pull strength. Clean both the surface of the panel as well as the glue tab with a PDR glue cleaning solution. Simply spray the solution on and wipe with a clean cloth.

Excessive Moisture on Panel

Ambient temperature and humidity play a huge role in proper adhesion. Using a heat gun, gently warm the panel to 120°F to eliminate residual moisture from cleaning and release any condensation. This will allow for the strongest bond between the glue pull tab and the painted surface of the panel.

Irregular Paint Surface

Contaminants bonded to the paint surface such as tree sap and road tar can interfere with adhesion—especially on older vehicles that have seen significant road use. Using a rubbing compound, lightly buff the damaged area to ensure a smooth surface for adhesion.

Waxes and Paint Protectants

Similar to paint contaminants, buildup of waxes and other paint protectants can interfere with adhesion. Most waxes and finishes can be removed with PDR glue cleaning solution. Certain waxes and aftermarket paint protectants may be more difficult and should be removed with specialized wax removing compounds.

Glue is Not Hot Enough

Glue should be dispensed at 375°F to allow for adequate adhesion and setup time. Properly heated glue will have wisps of smoke. Glue that is too hot will be bubbling (essentially boiling) and will result in less than ideal adhesions.

Not Enough Glue Applied

 The surface of the tab should be evenly coated in glue. When the tab is applied to the panel, a thin bead of glue should be visible around the edge of the tab. If no glue is visible, too little glue was used and could result in premature release of the tab.

Additional Resources

6Cs Process for GPR
6C Process - Printable Guide
6C Process Cards

     

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