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Application Guide - Above Waterline Application Systems

Surface Preparation and Priming

Surface Preparation

There are many situations where repainting is needed but removing all the old paint is impractical. However, the cost of labor and materials for a sand and repaint is significant and there is no gain in painting over a system that is severely deteriorated or chemically incompatible with the Awlgrip Systems.

When considering such a project, carefully evaluate the surface and the condition of the current topcoat and the coatings under it all the way down to the substrate. Old paint that is peeling extensively, heavily chalked, blistered or cracked should be completely removed.

Metal substrates should be thoroughly examined for corrosion. This includes obvious corrosion damage and slight blistering which may indicate corrosion just ready to break the surface.

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Large blisters or soft spots in the film may indicate old fairing work that is failing. On fiberglass substrates these conditions may be indicative of voids in the glass system or osmotic blistering. These conditions must be repaired before applying new coatings.

After initial evaluation perform the following three tests, in the order listed, to determine the adhesion of the old system and its chemical compatibility with the Awlgrip Systems.

Performing these tests on more than one area will add validity to the results. Make notes, collect chips and take photos for the job file. If any of the following compatibility tests fail, the old coatings must be removed down to a sound coating layer or to the substrate.

Please take this testing seriously as new epoxy-urethane systems have failed because of unstable underlying coatings and fillers. While the tests are not fool-proof, if strictly followed, they can be very accurate. Diligence in performing the tests can save hours of costly labor downtime and wasted materials.

Assuming the existing paint system passes the adhesion and compatibility tests, repainting would include the following:

  • Inspection of the surface

  • Removal of coatings which fail the adhesion and compatibility tests

  • Repair of defects

  • Priming the entire surface

  • Application of an Awlgrip or Awlcraft 2000 Topcoat (above water)

Conditions and remedies should be discussed with the owner, possibly using a condition report or making notes in the painting contract. Areas that were not repaired because of time or budget must be noted on the final invoice.