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Application Guide - Above Waterline Application Systems

Priming - Fiberglass/Gelcoat

New and sound aged gelcoat

  1. After cleaning, sand the entire surface smooth with 120–180 grit paper.
  2. Blow off the surface with clean, dry compressed air while dry wiping with clean rags to remove sanding dust and residue. Wipe surface with Awlgrip Wipe­-Down Solvent (NA/AP: Awlprep T0008; EU: Surface Cleaner T0340) using the Two Cloth Method.
  3. Apply specified number of coats of 545 Epoxy Primer with the appropriate overcoating interval between coats.

Tip

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The application of the 545 Epoxy Primer in the step above (provided sufficient DFT is applied and the sanded finish is acceptably smooth) can be seen as the final priming coat. Further application of 545 Epoxy Primer prior to topcoating would not be necessary.

Finish Priming options: 321 HS Undercoat 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 Sales Representative for alternative schemes.

Following sanding, if necessary, surface is now ready for final prime and topcoat.

Surfaces with heavily crazed, cracked, broken, delaminated gelcoat and raw laminating resin and epoxy coated/laminated wood.

  1. Any areas that have been previously ground out need to be primed with Hullgard Extra. Two or three coats may be needed. Allow to dry 12+ hours.
  2. Fill and fair as necessary with Awlfair LW. Allow to cure 12+ hours.

    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 (1mm deep x 1mm wide maximum use). Polyester putties shrink and distort rapidly. Epoxy fillers are much more stable.


  3. Sand the entire surface smooth with 80–120 grit paper. Remove all gloss from the gelcoat, oxidized gelcoat and lightly crazed areas. Feather any dents or scratches. Do not sand excessively. This will create porosity in the surface that will have to be filled.
  4. Blow off the surface with clean, dry compressed air while dry wiping with clean rags to remove sanding dust and residue.
  5. 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 Sales Representative for more information.

  6. Sand the entire surface smooth with 120–180 grit paper.
  7. Blow off the surface with clean, dry compressed air while dry wiping with clean rags to remove sanding dust and residue. Wipe surface with Awlgrip Wipe-­Down Solvent (NA/AP: Awlprep T0008; EU: Surface Cleaner T0340) using the Two Cloth Method.
  8. Apply specified number of coats of 545 Epoxy Primer with the appropriate overcoating interval between coats.

Tip

The application of the 545 Epoxy Primer in the step above (provided sufficient DFT is applied and the sanded finish is acceptably smooth) can be seen as the final priming coat. Further application of 545 Epoxy Primer prior to topcoating would not be necessary.

For brush/roll & tip applications, Awlquik may be preferred in place of 545 Epoxy Primer. Contact your local Technical Sales Representative for alternative schemes.

Following sanding, if necessary, surface is now ready for final prime and topcoat.