Reduced yield and excessive shrinkage leading to stud line cracking are the more common issues that SPF applicators face. The best rule of thumb is to stop applying foam to the walls if the foam looks "different," including:
| STYROFOAM™ Brand  SPF  Troubleshooting Tips |
| Observation |
Cause |
Potential Issues |
Potential Solutions |
| Color changes |
A/B off-ratio |
- Poor foam properties
- Excessive shrinkage
- Stud line cracking
|
- Ensure drum transfer pumps are working properly (steady static pressures).
- Ensure that chemical filters are not plugged and the check valves in the displacement pumps are operating correctly (steady dynamic pressures). A low polyol level will produce foam that is brittle and darker colored. A low isocyanate level will produce foam that is spongy and lighter in color.
|
| Color swirls |
Poor mixing |
- Poor foam properties
- Excessive shrinkage
- Stud line cracking
|
- Check the drum chemical temperatures and determine if between 60ºF and 90ºF.
- Determine if the dynamic pressures are approximately 800 psig or higher.
- Determine if the chemical temperatures are between 115ºF and 130ºF.
|
| Faster/slower than normal cream |
High/low chemical temperatures; high/low chemical pressures |
- Poor yield
- Poor foam properties
- Excessive shrinkage
- Stud line cracking
|
- Verify that drum temperatures are at the appropriate temperature.
- Determine whether the heater block has the capacity to heat the chemicals to the temperature for spraying at the desired rate.
- Ensure the line temperatures are operating properly.
- Ensure that the dynamic pressures are in the recommended ranges.
- Minimize exposure of the line to direct sunlight or severe cold.
|
| Non-circular or smaller/larger than usual spray pattern |
Plugging; high/low chemical temperatures; high/low pressures |
- Poor yield
- Poor foam properties
- Excessive shrinkage
- Stud line cracking
|
- Check the drum chemical temperatures and determine if between 60ºF and 90ºF.
- Determine if the dynamic pressures are approximately 800 psig or higher.
- Determine if the chemical temperatures are between 115ºF and 130ºF.
- Clean gun tip or remove and soak gun's mixing chamber. If mixing chamber cannot be cleaned with solvents, a burn-out oven may be required.
|
| Foam Reversion |
High chemical temperatures |
- Poor yield
- Poor foam properties
- Excessive shrinkage
- Stud line cracking
|
Foam reversion occurs when the mixing chemicals exit the gun as a froth or foam and then collapse. This is often due to excessively high temperature leading to boiling of the blowing agent in the mixing chamber. |
| Poor wetting of the substrate |
Dirty substrate |
Poor adhesion |
Clean the substrate. |
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Substrate incompatible with SPF |
Poor adhesion |
Prime the substrate. |
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