Troubleshooting Edge & Face Gluing

The following information is a summary of potential issues and recommendations. Check out our complete Edge & Face Gluing Guide for additional recommendations!

Issue: Weak joints with little or no wood failure
Possible Causes:

• ‍Poor stock machining | Recommendation: Check for mechanical malfunction, check adjustment of equipment and make sure blades are sharp
• Burnished surfaces | Recommendation: Increase feed rate on moulder /jointer and sharpen or replace cutter blades
• ‍Undercured or frosted joints caused by low temperature | Recommendation: Raise plant and stock temperatures
• ‍Undercured or frosted joints caused by short clamp time | Recommendation: Increase clamp time
• ‍Undercured or frosted joints caused by high moisture content | Recommendation: 6-8% moisture content
• ‍Undercured or frosted joints caused by thick glue lines | Recommendation: Check part fit and/or increase clamp pressure
  
  

Issue: Splits and/or open joints on ends of panels
Possible Causes:

• ‍High Moisture Content | Recommendation: 6-8% moisture content recommended.
• ‍Dry conditions in plant | Recommendation: 30% minimum relative humidity; use end sealer

Issue: Wood failure only over part of surface
Possible Causes:

• ‍Uneven pressure applied to top or bottom only | Recommendation: Apply pressure to top and bottom equally
• ‍Uneven pressure due to improper clamp spacing | Recommendation: Apply pressure near ends and 8-12" apart
• ‍Uneven pressure due to poor machining | Recommendation: Make sure that surfaces are flat and square
• ‍Uneven glue application | Recommendation: Coverage must be even over entire surface

Issue: Weak joints with wood failure along glue line
Possible Causes:

• ‍Grit of abrasive too coarse | Recommendation: 60 grit or higher recommended
• ‍Dull saw blades | Recommendation: Sharpen blades
  
  

Issue: Black glue lines
Possible Causes:

• ‍Iron contamination in adhesive | Recommendation: Isolate and eliminate contact source of wet adhesive with iron or steel

Issue: Brilliant white on glue squeeze-out and/or glueline
Possible Causes:

• ‍"Chalking" caused by low temperatures | Recommendation: Raise temperature of plant, wood and temperature above minimum use temperature of adhesive