b'482 $ All Prices inOsmosis Prevention and CureCanadian Dollars $Gel Coat Blister Repair1. Remove all coatings down to clean gel coat by sanding or professional sand sweeping. Surface should be left with a finish that looks and feels like the surface has been sanded with 80 to 100 grit sandpaper.2. Break open all blisters. If a power tool is used be sure it does not burnish the bottom of the blister site. A rough surface will assure adhesion of a fairing compound.In Canada this is best done in the fall so that the hull has the winter to dry out.NOTE often small blisters will disappear by the spring!Inspect your hull every liftout, not in the spring! 3. Survey the bottom area to determine the extent of blister damage. Should disbonding of gel coat or active laminate disbonding be suspect, seek a professional opinion. Small blistering generally involves gel coat only. Extensive blistering may involve laminate disbonding and radical procedures will be necessary.4. Wash entire surface to remove salts and residue of blister sites.5. Allow hull to dry. Be sure to dry out bilges, empty integral tankage, provide ventilation to all voids, cabinets, compartments and cabin areas. Vacuum bagging can be considered. Examine hull periodically for unbroken blisters. Frequently blisters will swell or shrink during drying. Mark or break them as soon as you see them as they may not be apparent at the time of your next examination.When in doubt seek a professional opinion. Should any barrier system be applied over entrapped moisture or unstable laminate reblistering will be sure to follow.6. Clean surface. When positive hull is dry and stabilized, wash the hull of dust and contaminants and allow surface to dry.7. Seal Surface. Brush coat entire surface with one coat of Pettit 4700/4701Barrier at 420 sq. ft. Gal. Be sure to brush in bottoms of all blister sites and voids. This procedure will ensure wetting down and sealing to fill minor irregularities.8. Fair hull with an Epoxy Compound.9. Clean surface of all dust and sanding residue in preparation for coating with epoxy. The Pettit 4700/4701Barrier must be applied by brush, roller or spray at the recommended rate to achieve the necessary film thickness and water impermeability. Calculate the square footage of the area to be coated and divide that by 140 square feet per gallon to determine the quantity of Pettit 4700/4701Barrier that will be needed. Each coat at 140 sq. ft. per gallon will yield 7 mils dry film. Plan to apply three coats to yield 21 total mils dry film thickness. Apply primer following label directions.10. Apply two coats of anti-fouling paint.482 email: hmp@hollandmarine.comwebsite: www.hollandmarine.comfax:905-891-7972tel:905-891-1639'