Not enough adhesive applied to joint area or insufficient adhesive remaining in joint area.
| CAUSE |
SOLUTION |
| Foamy Mix/ Adhesive Mix Too Thin or Too Thick
| Check equipment used to mix adhesive. |
| Check proper mixing proportions of adhesive by weight when a two part system is used. |
| Insufficient Adhesive Spread
| Recover and/or regroove worn spreader rolls. |
| Replace worn bearings on spreader rolls if needed. |
| Use proper roll grooving and the required spread rate for type of adhesive used. |
| Spreader rolls must be parallel with each other and with doctor rolls. |
| Keep spreader rolls clean of dried adhesive. |
| Be sure top and bottom rolls apply an equal spread of adhesive. |
| Fast operation of spreader may cause foaming of adhesive. |
| Apply proper spread of adhesive for porous and nonporous stock. |
| Soft and porous stock may need heavier spread rate than dense stock as adhesive can soak in too quickly. |
| Excessive Pressure
| Avoid excessive pressure on less dense stock. |
| Porous Stock
| Apply proper adhesive spread of adhesive for porous stock. |
| Porous stock may need heavier spread rate than dense stock as adhesive can soak in too quickly. |
| Low Moisture Content
| Moisture content of core and face stock should be 6% to 10%, veneers 3% to 6%, to avoid excessive soak-in of adhesive. |
| Assembly Time Too Long
| Shorten assembly time by making fewer pieces before pressing. |
| Increase spread rate. |
| Insufficient or Non-Uniform Pressure/Non-Uniform Stock Thickness
| Do not use stock when dimensions vary. |
| Press must deliver recommended pressure in order for surfaces to be brought into intimate contact. |
| Adjust planers to avoid excessive planer marks. Typically, 16 to 32 marks per inch are recommended. |
