Any variation from a flat, true panel.
| CAUSE |
SOLUTION |
| Unbalanced Construction
| Avoid bonding diagonal grain veneers. |
| Use same species and thickness of veneers for faces and back where possible. |
| Non-Uniform Moisture Content
| Do not dry core stock below 5% or veneers below 3% moisture content. |
| Humidify plant if below 25% relative humidity. |
| Non-Uniform Spread
| Avoid wavy or warped veneers where possible. |
| Do not use veneers of unequal thickness for assembly. |
| Recover and/or regroove worn spread rolls. |
| Replace worn bearings on spreader 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. |
| Faulty Core Stock
| Avoid worm-holes, dents, knots and fillers that hold too much adhesive. |
| Do not use woods of different density or species in the same cores. |
| Do not use boards in core stock that are more than 2" (5.08 cm) wide. |
| Avoid rough, rotary cut veneer cores. |
| Avoid sunken joints in core stock. |
| Do not sand or plane cores immediately after edge bonding. |
| Press Temperature Too High
| Do not use high hot-press temperatures to attain shorter press periods unless moisture content of stock is carefully controlled. |
| Over-Curing in Hot-Press
| Avoid excess drying and over-curing. |
| Do not leave panels in hot press during lunch or breaks. |
| Always remove panels as soon as press is opened. |
| Improper Conditioning
| For gradual cooling of panels and to prevent warping, panels should be squarely dead stacked and weighted for at least 12 hours after removing from press. |
