| Problem |
Possible Cause |
Solution |
| Stencil peels or washes away during washout |
Underexposure |
Perform a Step Wedge Test |
| Poor fabric preparation |
Degrease steel & metalized polyester, abrade & degrease synthetics |
| Residual moisture in stencil during exposure |
Under humid conditions, stencil may require additional drying after backing sheet removal |
| Washout temperature is excessive |
Stay below 40oC (104oF) |
| Silk or cotton organdy |
Use only synthetics, stainless steel, or metalized polyester |
| Air Pockets |
Fabric not wet enough |
Mesh openings must be filled with water; rinse just before adhering; check fabric preparation; use vertical, newsprint technique for thin CDF and fine mesh |
| Poor fabric preparation |
Degrease steel & metalized polyester; roughen & degrease synthetics |
| Poor fabric stretching |
Upgrade stretching method |
| Adhering surface not flat |
Use completely flat surface |
| Irregular or missing squeegee stroke |
Use sharp-edged, medium hardness squeegee with slow steady stroke, without excessive pressure |
| Stencil breakdown |
Underexposure |
Perform Step Wedge Test |
| Poor fabric preparation |
Degrease steel & metalized polyester; roughen & degrease synthetics |
| Solvents too agressive |
Coat squeegee side with 569FAST; use CDF/LX or CDF/QSR film |
| Needs mechanical reinforcing layer |
Coat squeegee side with FX88 (RLX for CDF/LX, QFX for CDF/QSR or QTX for CDF/QT) |
| Aqueous or water-containing ink |
Use CDF/LX series or CDF/QT |
| Poor definition (edge sharpness) |
Waiting too long before squeegee stroke |
Have squeegee ready after film contacts wet mesh |
| Mesh too coarse for film |
Use thicker film; stencil thickness must be related to mesh count |
| Underexposure |
Perform Step Wedge Test |
| Incomplete washout |
Wash out thoroughly from both sides |
| Poor Resolution (fine details) |
Positives lack density |
Remake positives |
| Pre-exposure |
Work under safelights; store coated screens in dark |
| Poor exposure contact |
Check vaccuum |
| Poor light source |
Upgrade light source; increase exposure distance if possible |
| Mesh too coarse |
Use finer mesh |
| Film too thick |
Use thinner film |
| Overexposure |
Perform Step Wedge Test |
| Pinholes |
Dirt and dust |
Clean positives and contact glass; remove backing just before exposure; dust film emulsion before adhering |
| Underexposure |
Perform Step Wedge Test |
| Solvents too aggressive |
Coat on squeegee side with 569FAST; use CDF/LX or CDF/QSR series film |
| Poor fabric preparation |
Check preparation' adhere as soon as possible after the degreasing rinse |
| Difficulty reclaiming |
Underexposure |
Increase exposure to fully cure emulsion |
| Wrong stencil remover |
Use only Ulano No. 4, diluted No. 44, No. 42 or No. 5 |
| Solvents too aggressive |
Coat on squeegee side with 569FAST; use CDF/LX or CDF/QSR series film |
| Thicker stencil needed |
Mesh too coarse |
Use finer mesh, if possible; use thicker CDF Direct-Film; use Direct-Indirect Method, or Lamination Technique |
