Join Date: Jul 2000
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Gelcoat repair discoloration
Could be just absorbtion of atmospheric pollution, tannins, etc. into a porous gelcoat repair.
Try removing all the old dead wax with a strong alkaline detergent, rinse well, then bleach the staining with oxalic acid.
Oxalic can be obtained in a paint or hardware store.
If that''s the cure, be sure to ''close'' the surface by high speed power buffing and then making sure you keep a good wax on the surface to seal the surface.
Hope this helps.