Conversion Varnish Viscosity & Gun Setup Log
Daily verification of conversion varnish viscosity (Zahn #2 cup seconds), fluid/atomizing air pressures, fan pattern quality, and gun cleanliness. Each row represents a single station check; any parameter outside tolerance triggers a corrective action entry.
This log captures the critical parameters that directly affect conversion varnish finish quality: viscosity (measured in seconds with a Zahn #2 cup), fluid pressure (psi at the pot regulator), atomizing air pressure (psi at the gun inlet), and fan pattern uniformity. Each shift lead or finishing technician records a pass/fail for every station. Any failed reading triggers a corrective action row on the defect log below. Consistent use of this form reduces orange peel, sags, and solvent pop rejects by ensuring the material and gun are in spec before production spraying begins.
- Lockout/tagout the pressure pot and verify air supply is isolated before cleaning the gun or changing the regulator.
- Wear solvent-resistant gloves, safety glasses, and a NIOSH-approved organic vapour respirator when handling conversion varnish and cleaning solvents.
- Use a clean, dry Zahn #2 cup and a calibrated stopwatch. The cup must be free of dried varnish from the previous reading.
- Spray booth ventilation must be active and verified (min 100 ft/min face velocity) before any atomization takes place.
Inspection / Log Matrix
| Status (P/F) | Inspection Item / Task | Tolerance / Threshold | Actual Reading |
|---|---|---|---|
| [ ] Pass [ ] Fail | Varnish temperature at gun inlet | 18 – 24 °C | ________ °C |
| [ ] Pass [ ] Fail | Zahn #2 viscosity (seconds to break stream) | 22 – 30 seconds | ________ sec |
| [ ] Pass [ ] Fail | Fluid pressure at pot regulator | 20 – 40 psi | ________ psi |
| [ ] Pass [ ] Fail | Atomizing air pressure at gun handle | 40 – 60 psi | ________ psi |
| [ ] Pass [ ] Fail | Fan pattern shape (test spray on liner card) | Even oval, no tails or fingers | Visual OK? ____ |
| [ ] Pass [ ] Fail | Fluid tip / air cap cleanliness (no dried varnish) | Zero residue on disassembly | Visual OK? ____ |
| [ ] Pass [ ] Fail | Pressure pot gasket and lid seal check | No audible hiss, no drips | Visual OK? ____ |
| [ ] Pass [ ] Fail | Varnish batch ID & pot life remaining | Batch code on drum; pot life ≥ 2 hr | Batch: _______ / Pot life: ___ hr |
Defect / Corrective Action Log
| Date / Time | Item # | Issue Identified | Corrective Action Taken | WO # |
|---|---|---|---|---|
| ___/___/_____ __:__ | _______ | _________________________________ | _________________________________ | _______ |
| ___/___/_____ __:__ | _______ | _________________________________ | _________________________________ | _______ |
| ___/___/_____ __:__ | _______ | _________________________________ | _________________________________ | _______ |
| ___/___/_____ __:__ | _______ | _________________________________ | _________________________________ | _______ |
| ___/___/_____ __:__ | _______ | _________________________________ | _________________________________ | _______ |
By signing below, the inspector verifies that all items have been checked according to the manufacturer's specifications and facility safety standards. Any failed items have been transferred to the corrective action log with a corresponding work order number.