Painting
In preparation for painting
I have been doing some research on painting systems. I used MPI as a source for the results below. Some paints could be verified using search function on various boat building forums such as Paints & Coatings of MBS.
| MPI # | Desc | Top coats | Surface Prep SSPC | Application | Cloverdale/Sherwin-Williams/Sigma |
|---|---|---|---|---|---|
| 18 - Zinc Rich Organic | A solvent based, one component for marine environment suitable for immersion | Not specified | SP-5 (white metal) | Airless and spray, but brushes or rollers may be used for small work or touch-up | ClovaZinc 1/Zinc Clad V/NA |
| 19 - Zinc Rich Inorganic | For severe marine environment | MPI #77, 98, 108. #98 or 108 is recommended as an intermediate coat for #72 finish for longivity for exterior surfaces | SP-5 (white metal) | Airless and spray, but brushes or rollers may be used for small work or touch-up | ClovaZinc 2/ Zinc Clad II Ethyl Silicate/ Silguard SC |
| 20 - Zinc Rich Epoxy | Solvent-based, 2-3 component epoxy for moderate exposure in marine environment | MPI #77, 98, 108 | SP-6 Commercial blast min, hand or power tools is acceptable sometimes | Airless and spray, but brushes or rollers may be used for small work or touch-up | ClovaZinc 3/Zinc Clad IV/Simgarite Zinc Primer |
| 101 - Anti-corrosive Epoxy | A solvent based, two component, epoxy - polyamide type, for exterior and interior, ferrous and galvanized metal surfaces | MPI #77, 98, 108 | Not specified | Application methods will include using brushes, rollers, and airless and conventional spray | ClovaPrime 21 Epoxy/ Duraplate 235 Multi-Purpose Epoxy/NA |
| MPI # | Desc | Primer | Application | Cloverdale/Sherwin-Williams/Sigma |
|---|---|---|---|---|
| 72 - Two-Component Pigmented Polyurethane, Gloss | A solvent based, two component polyurethane, pigmented coating with a gloss finish... for metal surfaces where abrasion, weathering, chemical and solvent resistance is required | MPI #19 | Primarily applied by spray, but can be applied by brush or roller in small areas | ClovaThane 834 Series/NA/NA |
| 77 - Epoxy, Gloss | A solvent based, two component, epoxy/polyamide coating for heavy traffic in moderate industrial environments. Must be resistant to incidental splash and spillage of dilute (5%) sulfuric acid, (15%) hydrochloric acid, (20%) sodium hydroxide, gasoline and heavy duty cleaners and detergents | MPI #19, 20 101 | Application is generally by spray, but in areas where spray is impractical, a brush or roller may be used. Temperature: 15 - 40° C, max rel. humidity 80% | NA/Tile-Clad HS Epoxy/NA |
| 98 - High Build Epoxy, Gloss | A solvent based, two component epoxy for protection to exterior/interior steel surfaces in marine environments. Used as an intermediate coat for MPI #72 | MPI #20, 101 | Primary application is airless or conventional spray, but small areas can be touched up by brush | ClovaCoat 300, ClovaMastic/ SherTile HS Epoxy, B67-200 Series/ NA |
| 108 - High Build Epoxy, Low Gloss | A two component epoxy, high solids coating for use on interior or exterior primed metal surfaces. For increased durability, this product may be top coated with epoxy or polyurethane enamels. | MPI #19, 20 , 101 | Not specified | ClovaGuard/ Macropoxy 646 Fast Cure Epoxy/ Sigma Multimastic |
It appears that organic zinc rich primers are most suitable for the interior. Particularly ClovaZinc 1. As a single component, it is ready to be used. It can be applied over other zinc rich coatings or to cleaned to SP-6 or SP-10 metals. It touch dries in 10-15 minutes and hard dries in 12 hours. Min time for overcoat is 1 hour, normal 8 and max is indefinite. Application temperature should be above 7° C. It has excelent moisture, weather, oil, salt and fresh water resistance. If immersion or strong chemical resistance is required, then it should be top-coated with high performance coatings, which may be applicable to bilge area.