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POR-15 Application Process

Simple tips on getting the most out of using POR-15 through the application process.

Rusted surfaces are best; seasoned metal and sandblasted surfaces are also good.

First, wire brush loose rust and scale. Then remove any grease or oil with POR-15 MARINE-CLEAN and prep with POR-15 METAL-READY. DO NOT USE SOLVENT- BASED CLEANERS.


To coat smooth metal surfaces:



Use POR-15 METAL-READY to prepare surface before painting. Surface must be dry and free of grease, oil, or other foreign substances. Use of 'rust converter' products is not recommended as they may affect bonding of POR-15 to metal. POR-15 likes to adhere to surfaces with 'tooth' rather than smooth, glossy surfaces.



Stir contents thoroughly before painting. Do not shake.

Refrigerate unused portion of POR-15 for longer shelf life.



Apply in thin coats, 1 to 2 mil thickness. Minimum 2 coats.



Topcoat when first coat is dry but with slight finger-drag remaining, usually 4-5 hours.



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Spray Gun Application:


Use 30-35 lbs pressure for normal gloss. Reduce pressure for lower gloss (20-25 lbs). Thin only with POR-15 Solvent, if necessary, but do not thin more than 5%.

To topcoat a fully cured POR-15 surface:



Wet sand with 600 grit until gloss is dull, then paint, or use POR-15 Tie-Coat Primer directly on the cured POR-15 surface, then topcoat as desired. NOTE: Never topcoat a POR-15 surface that hasn't dried, as this will ruin the coat already down. Use POR-15 Solvent or lacquer thinner for cleanup, which must be done before POR-15 dries. NOTE: Organic vapor particulate respirators, NIOSH/MSHA approved, must be used when spraying POR-15.



Moisture will shorten the life of unused POR-15. Seal can or jar immediately after using. We recommend placing plastic wrap between lid can and storing in a cool dark place.

Application of POR-15 to new, unpainted metal surfaces:



For proper adhesion to aluminum, galvanized metal, and smooth steel surfaces, prep with POR-15 METAL-READY Rust Remover/PrePrimer. Keep surface wet for 15 minutes, then rinse off with water and dry thoroughly. This process will leave a zinc phosphate coating on the metal and insure perfect adhesion.


Standard Applications:

  • Use as a primer or finish coat
  • Automobiles: fenders, floorboards, bumpers. trunk areas, engine compartments, rockers
  • Trucks, trailers, agricultural equipment, snow removal and highway equipment>
  • Storage tanks, bridges, boats, factory machinery
  • Outdoor sign supports, fencing, metal roofs, fire escapes
  • Use to waterproof insulation or wood
  • As a filler for metal
  • Use as a bonding agent on wood or styrofoam
  • Prevents rust in refrigeration units where moisture corrodes metal
  • Use on lawnmower housing to prevent rust; keep grass from sticking and clumping in wet weather.

Which product to use?

  • POR-15 SILVER contains metal filler and should be used on badly rusted steel to fill small holes and pitted areas.
  • POR-15 BLACK is used on frames, floorboards. under fenders, engine compartments. trunk areas, etc.
  • POR-15 CLEAR dries to a perfect satin gloss, used on exterior surfaces before painting. Excellent for "touch-up".
  • POR-15 GRAY is ideal for use on concrete.

Advantages over most dual-component coatings:

Better chemical resistance, better adhesion to metals, greater ease of application, strengthened by exposure to moisture. Reasonable pot life, non-shattering, great flexibility. No catalyst required for curing. 

Container Size Availability:

  • Pint
  • Quart
  • Gallon
  • 5 Gallon Pail
  • 55 Gallon Drum

Ultra-Violet Sensitivity

POR-15 is sensitive to UV light (sun) and must be top coated for prolonged exposure to sunlight. Failure to do this may result in long-term damage to the POR-15 coating. Top coating is not required for areas not exposed to sunlight.

Laboratory Test Results

POR-15 was tested for 168 hours at 97°F in a condensing humidity salt spray (ASTM B117). At the end of the test period, coated steel was free of rust or pitting. Acid and alkali resistance tests performed found panels coated with POR-15 to be impervious to gasoline, oil, Chromic acid, hydrochloric acid, phosphoric acid, sodium hydroxide, caustic soda, 50% sulfuric acid, and 50% hydrofluoric acid. POR-15 was applied over a rusty substrate as a finish coat (approximately 23 mils dry film thickness). The coating showed essentially no undercutting at the scribed area after 2000 hours in a weatherometer

A 2 mil thickness of POR-15 was applied to lightly rusted steel and then exposed for 1000 hours to a salt spray. At the end of the test period, no undercutting was observed at the scribed area. Recoatability is excellent. Laboratory tests have shown very good adhesion when applied up to 14 days after application of the first coat. In an actual Field test, a topcoat was applied 6 weeks after the first coat had been applied, and the intercoat adhesion was excellent as determined by a crosshatch tape test. A metal box used as a filter for raw sewage was coated with POR-15 and placed in service within a few hours after the interior and exterior were coated. No visible rusting occurred at the welded areas after a six month exposure.

A POR-15 coating was subjected to 700°F for 10 hours; it remained hard and showed no apparent loss of adhesion. A panel subjected to elongation was pulled beyond the yield point of the base metal without affecting the POR-15 coating.

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