Overlapping
The edge of one piece of veneer is on top of the other. The veneer is not being held flat. | The pressure bar may be too high. | Check the float gauge. Lower the pressure bar. |
The front suspension bolt is too tight. This lifts the infeed end of the upper heater bar. | Loosen the suspension bolt. | |
Upper heater bar is too high. | Reset the upper heater bar. | |
The front end of the heater strip is not against the lower heater bar. | Place a slight bend in the heater strip 4″ from the infeed end. | |
The heater strip will not “float” up and down at the infeed end. | Check the lower heater bar for level. The feed chains are pulling on the heater strip. | |
The pressure setting is too light.Check for pressure marks, the shine, on the veneer. | Increase the pressure setting. | |
The veneer overlaps before entering the feed chains. | The holddown springs on the matching roll are not holding the veneer flat. | Lower the holddown assembly. |
Replace the holddown split springs. | ||
The matching rolls pull the veneer into the machine at angles. | Readjust the cant on the matching rolls. | |
Reduce the pressure on the matching rolls. | ||
The edge of the veneer curls up against the infeed guide. | Readjust the cant on the matching rolls. | |
If the veneer is curled at the edge set the holddown block as close to the matching roll and as low as is possible. | ||
The jointed edges of the veneer are not square. | Check the jointer blade for sharpness. Only use the veneer edge from the flat side of the Guillotine. | |
The veneer overlaps on one or both ends only. | The edges of the veneer are not straight or parallel. | Check the jointer. |
Mismatching
The ends of the spliced veneers are offset. | Improper feeding. The veneer is fed into the machine unevenly. | Align edges and use only one hand to feed both sheets of veneer. |
Mismatches under the matching rolls. | Too much or too little spring pressure on the matching rolls | |
Large lower idle roll not turning with feed chains. Replace bushing. | ||
Matching rolls and/or lower feed rolls worn. Replace parts. | ||
Burr on the infeed guide or table catching the veneer. Repair. | ||
Mismatching at the beginning of feed chains. | Heater strip not “floating” up and down. Check adjustments of lower heater bar. Reset machine. | |
Pressure bar is too low. Check the float gauge. | ||
The suspension bolt is too loose. Tighten the suspension bolt. | ||
Upper heater bar is too low. Readjust the heater bar . | ||
Mismatches while under the pressure bar. | Check the adjustment of the lower heater bar, the upper heater bar, and the pressure shoes. | |
Pressure bar is too low or high. Check the float gauge. |
Burning of Veneer
Dark brown scorch lines on either side of the glue line. Usually dominant on the bottom side from the lower heater bar. | Excessive heat from either the upper or lower heater bar. Also crystallizes the glue. | Lower the temperature setting. See temperature/thickness chart. |
Increase the feed rate. |
Burnishing of Veneer
Crushed and shiny surface along the glue line. | Too much pressure. | Check the pressure setting. |
Crimping of Veneer
The veneer is crimped within 1″ of either side of the glue line. | The inside edges of the feed chains are worn. | Replace the feed chains. |
Reduce the pressure. |
Marking of Stock
Indentations left by the serrations in the lower feed chains. | Improper pressure setting. | Reduce the pressure setting. |
Incorrect adjustment of the splicer. | Check the adjustment of the lower heater bar, upper heater bar, and the pressure shoes. |
Grooving Along the Glue Line
Gouges or indents in the veneer next and parallel to the glue line. Can be either top or bottom face. | Build up of crystallized glue on either the upper heater strip or lower heater bar. | Excessive glue on the veneer is the source of the problem. Clean the upper strip and lower bar. If scraping is necessary use only soft materials such as wood, brass, or bronze. Running a heavy piece of veneer crossways through the splicer will usually clean them. |
Nicks or burrs on the upper strip or lower heater bar. | Repair or replace. |
Incomplete Glue Joint
The leading end of the veneer is spliced but the trailing end is open. | The edges of the veneer are not parallel. | Check the jointer. |
Poor Jointing
The sections of the veneer are spliced but sections open. Slight openings found along the glue line. | Inconsistent or insufficient glue spread. Sections of the veneer received too little glue or none. | Check the method of applying glue to the veneer. |
Small slivers of the veneer were torn out along the edge. | Check the jointer. |
Excessive Glue Spread
A build up of glue on the surface of the veneer. | Too heavy of a glue spread on the veneer. | Check the method of applying glue. |
Tear out of the veneer along the glue line. | Build up of crystallized glue on either the upper heater strip or lower heater bar. | Check the method of applying glue. |
Crimping
The leading edge of the glue line is pushed back along the glue line. | Build up of crystallized glue on either the upper heater strip or lower heater bar. | Check the method of applying glue. |
Lower heater bar is high. | Readjust the lower and upper heater bars. |
Blue Staining
Metallic stain marks on either side of the glue line caused by condensation and moisture. More common on high humidity days. Generally exist in coarse grained oak. On veneer already stained, the ink can be removed by applying a 10% oxalic solution to the stain. | Moisture content of veneer is too high. | Dry veneer to lower moisture content. Store in humidity controlled area. |
Glue is wet when veneer is spliced. | Allow the glue to dry completely before splicing. | |
Humidity in area is high. | Reduce the temperature setting as much as possible and increase the feed rate. | |
Install a compressed air jet blowing on each pressure chain in the pressure bar. | ||
Install a hot air gun in the center hole in top of the pressure bar. | ||
Install chrome plated chains. |