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Application Guide - Above Waterline Application Systems

Surface Preparation and Priming - Previously Painted Surfaces Compatibility

Surface Preparation: Coatings Compatibility & Adhesion Tests (Above Water Only)




Test One: Cross Hatch Adhesion (See diagram above)

  • Select test area(s) on the surface to be painted. Thoroughly clean, de–wax and degrease this area.

  • With a sharp blade, cut 6 lines vertically and 6 lines horizontally to give a box of 25 squares. The cuts must be deep enough to reach the substrate. On thick fairing systems this test may have to be done to several different layers.

  • Apply 3M #610, #895 or #898 3M Scotch Brand Filament Tape (or similar type of packaging tape) over the scribed area, making certain that the tape is tightly adhered to the test surface. Do not use masking tape.

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  • With an abrupt yank, pull the tape back parallel to the surface. Pulling the tape straight up will give no test at all.

  • Examine the test surface. If any square of old coating in the scribed area is removed, the adhesion has failed. All the failed layers must be removed.


Test Two: Solvent Resistance

  • Saturate a cotton ball or small wad of cloth with one of the Awlgrip Topcoat or Primer Reducers (T0003 or T0006).

  • Tape the reducer-saturated ball to the scribed area surface for 30 minutes.

  • After 30 minutes remove the cotton ball. If the reducer has dissolved or severely softened the old coating, the coating is incompatible and must be removed. If the scribed area has remained intact, allow a 15 minute recovery period and repeat all steps in Test One again.

  • If any square areas are removed, all the failed layers must be removed.


Test Three: Coating Compatibility

If the old coating is still intact after Tests One and Two, perform Test Three.

  • Lightly sand a small test area with 220 grit paper. Clean the sanded areas thoroughly with Awlgrip Wipe Down Solvent (NA/AP: Awlprep T0008; EU: Surface Cleaner T0340) and using clean cloths.

  • Paint a small patch of the surface with Awlgrip Topcoat. Do not use masking tape on the edges of the test application as the paint edges created by the tape will “print through” and be visible in the finish.

  • Allow the coated area to cure for 24 hours, at temperatures above 77˚F (25˚C).

  • After the area has been allowed to cure, check for intercoat adhesion with Test One – Cross Hatch Adhesion Test.

  • If there is no lifting, wrinkling or loss of adhesion caused by this cross hatch test, the Awlgrip Systems are compatible and surface preparation can begin.


If this test fails, all coatings must be removed down to a sound, well adhered, compatible coating or to the original substrate.

Surfaces that are sound and chemically compatible with Awlgrip Systems and no heavy filling or fairing is required.

  1. Thoroughly clean the surface, scrubbing with powdered household scouring cleanser. Wipe with Awlgrip Wipe-­Down Solvent (NA/AP: Awlprep T0008 or Awlprep 400 T0170; EU: Surface Cleaner T0340), using the Two Cloth Method. These procedures are outlined here.
  2. Inspect the surface for imperfections. Mark the imperfections with a pencil. Do not use felt tip marker or ink pen.
  3. Sand the imperfections with 80 grit paper creating both a feathered edge and a proper surface profile over which primers and fillers can be applied.

    Caution

    If polyester putties are used they should be kept to an absolute minimum. Only use polyester putties for pinholes and very slight scratches. Polyester putties shrink and distort rapidly. Epoxy fillers are much more stable products. Do not apply polyester putties over or under Awlfair LW.


  4. Prime these filled and sanded areas with 545 Epoxy Primer (Spray). Allow to cure 12 hours or overnight.

Note: For large filled areas, use of 545 Epoxy Primer is not recommended directly to the filler. Prime these areas with High Build.

Priming options: 345 HS Epoxy Primer can be used in place of 545 Epoxy Primer in areas with VOC restrictions. For brush/roll & tip applications, Awlquik may be preferred in place of 545 Epoxy Primer. Contact your local Technical Representative for alternative schemes.

After sanding the entire surface is now ready for priming.

Surfaces that are rough and require additional surfacing/filling.

  1. Thoroughly clean the surface, scrubbing with powdered household scouring cleanser. Wipe with Awlgrip Wipe-Down Solvent (NA/AP: Awlprep T0008 or Awlprep 400 T0170; EU: Surface Cleaner T0340), using the Two Cloth Method. These procedures are outlined here.
  2. Inspect the surface for imperfections. Mark the imperfections with a pencil. Do not use felt tip marker or ink pen.
  3. Sand the imperfections with 80 grit paper creating both a feathered edge and a proper surface profile over which primers and fillers can be applied. Note: On metal boats any bare metal exposed by sanding must be primed with Hullgard Extra or Max Cor CF before applying other primers or fillers as necessary.

    Caution

    Do not use a roller to apply the primer as the sharp metal will snag fibers from the roller. These fibers can act as wicks for moisture or other contamination to enter the paint film. This can lead to premature failure of the Awlgrip Coating System.

    For further information contact your Technical Service Representative. Also see aluminum, steel or blister repair sections for details on bare metal surface preparation and priming.

    Caution

    If polyester putties are used they should be kept to an absolute minimum. Only use polyester putties for pinholes and very slight scratches or dents. Polyester putties shrink and distort rapidly. Epoxy fillers are much more stable products. Do not apply polyester putties over or under Awlfair LW.


  4. Sand the entire surface smooth with 80–120 grit paper. Remove all gloss from the previous finish.
  5. Blow off the surface with clean, dry compressed air while dry wiping with clean rags to remove sanding dust and residue. Wipe surface with (NA/AP: Awlprep T0008 or Awlprep 400 T0170; EU: Surface Cleaner T0340) using the Two Cloth Method.
  6. Prime the entire surface with High Build. Two coats may be needed. Allow to cure 12 hours or overnight.

Other alternatives schemes, such as replacing High Build with Ultra Build, are available. Contact your local Technical Service Representative for more information.

After sanding, the surface is now ready for fairing and surfacing if necessary. (See Fairing and Surfacing section for detailed information).