Description
CorrVerter® is a water-based rust converter primer that turns existing rust into a hydrophobic passive layer instead of blasting it off. One coat, water cleanup, and 0.1 lbs/gal VOC. Remove loose rust first — it reduces surface prep, it does not eliminate it. The 1-gallon can covers roughly 115 to 190 sq ft at the recommended film, sized for touch-up and small repairs.
CorrVerter is for the steel you cannot blast: structures in service, equipment in a plant that cannot be shut down, rebar and embedded steel on a repair job, outdoor assets where containment for abrasive blasting is impractical. It contains a chelating agent that binds the iron oxide into a stable, hydrophobic, paintable layer, and Cortec notes it contains no tannic or phosphoric acid. Surface preparation drops to SSPC-SP2 hand-tool cleaning, the lowest of any Cortec coating. It is strictly a ferrous product: in the Cortec Product Consultation Guide it is rated 5 on carbon steel, stainless steel and cast iron and not recommended for aluminum, galvanized steel, copper, brass or solder, because there is no rust to convert.
Typical applications
- Rusted steel requiring minimal surface preparation
- Rust conversion prior to topcoating
- Maintenance repainting over corroded substrates
- Field and touch-up primer work
- Structural steel, tanks and piping that cannot be taken out of service for blasting
- Rebar and embedded steel on concrete repair projects
- Transmission towers, bridges and outdoor steelwork repainted in place
- Plant maintenance where abrasive blasting is not permitted or not practical
How to apply CorrVerter
- Surface preparation. Remove loose rust, scale, dirt, oil and grease to SSPC-SP2 hand-tool cleaning (wire brush, scraper or power tool). Tight, adherent rust stays; CorrVerter converts it. The surface must be free of grease and oil, so degrease with an alkaline cleaner such as VpCI-414 and rinse if needed. Do not apply to bare aluminum, galvanized or non-ferrous metal.
- Mixing and dilution. Power-agitate to a uniform consistency with a squirrel-cage or drill mixer. CorrVerter may be thinned with water up to 15 % by volume to adjust viscosity.
- Conditions. Apply between 45 and 90 °F (7 to 32 °C) with the surface at least 5 °F (2 °C) above the dew point. Do not apply if the surface will freeze before it dries.
- Equipment. Spray, roll, brush or dip. HVLP or conventional spray: 0.009 to 0.021 in tip, 45 to 55 psi air and 10 psi fluid, 3/8 in ID fluid hose no longer than 50 ft, dual-regulated pot kept at gun height. Airless or air-assisted airless: 0.015 to 0.035 in tip, 1,800 to 2,500 psi, 3/8 in ID hose (a 1/4 in whip end is fine) no longer than 100 ft. Tip size depends on pressure and viscosity. Brush and roller are the usual field methods; the product is a 900 to 2,000 cP liquid, so airless spray suits large areas.
- Film build. One coat at 3.0 to 5.0 mils (76 to 127 µm) dry, 8.3 to 13.9 mils wet. Theoretical coverage is 577.9 sq ft per gallon at 1.0 mil DFT, so plan on roughly 115 to 190 sq ft per gallon at the recommended film; rough, pitted rust takes more.
- Drying and topcoating. Dry to touch in 2 to 3 hours and dry to handle in 4 to 6 hours; topcoat between 6 and 72 hours, sanding after that. Force-dry 15 to 20 minutes at 150 °F (65 °C) if needed. Full cure takes 3 to 7 days. All Cortec high performance coatings can go over it; verify compatibility on a test patch before applying a solvent-based topcoat.
- Cleanup. Clean tools with water while wet; once dry use a solvent-based paint stripper, following the manufacturer’s safety directions.
- Storage. Keep the container sealed, do not let it freeze and do not store above 100 °F (38 °C). Shelf life is 1 year.
- See the Cortec coatings application guides and comparison table for the shared spray, prep and storage instructions across the Cortec coating range.
Where it fits in the Cortec line
CorrVerter is sold in a 1-gallon can and a 5-gallon pail. It is the third option in Cortec’s surface-prep workflow of clean, strip, derust, protect. If the part can go into a tank, the rust removers VpCI-422, VpCI-423 gel and VpCI-426 take the rust off entirely and leave bare metal for any coating; if the steel can be blasted, an abrasive blast room gets to SSPC-SP6 and opens up the whole coating line. CorrVerter is for the steel that can do neither. Over it, VpCI-396 moisture-cure urethane is the brochure’s partner for marginally prepared structural steel, VpCI-386 and VpCI-375 are the water-based acrylic finishes. Browse the full Cortec VpCI line.
Field notes
A Minnesota collector treated the rusty underbody and floor of a 1947 sedan in a heated garage over the winter: scrape and degrease, just enough CorrVerter to stop the rust, dry and cure, then VpCI-386 Black as topcoat. Almost 14 years later there is no rust creep at the nuts and bolts. (Cortec Case History #769)
A Spooner, Wisconsin aerosol filler had rusting tanks and piping feeding its line, and NFPA rules require tank farms be protected from corrosion. The crew degreased with VpCI-415, pressure-washed, brushed CorrVerter on the rusted areas and sprayed VpCI-386 White as the topcoat, finishing four tanks and 200 ft of piping in about three days. (Cortec Case History #365)
A Wisconsin forklift-leasing company saw trucks leased 1 to 2 years into a brine and sauerkraut plant come back with slashed resale value. Now CorrVerter goes on rusted areas as needed, EcoShield VpCI-386 on all painted metal, CorShield VpCI-369 on unpaintable moving parts and ElectriCorr VpCI-239 on exposed electrical connections, touched up monthly. The trucks stay resalable and the program was copied for a foundry lease. (Cortec Case History #737)
Watch: Cortec coatings technology
Video by Cortec Corporation.
Specifications
| Salt fog (ASTM B117) | 336 hours (3 mil CorrVerter on lightly corroded steel, topcoated with 2 mil VpCI-386 White) |
|---|---|
| Humidity (ASTM D1735) | 250 hours |
| VOC | 0.1 lbs/gal (12 g/L) |
| Volume solids | 36.0% |
| Coverage | 577.9 ft²/gal @ 1.0 mil DFT |
| Recommended DFT | 3.0–5.0 mils (76–127 µm) |
| Pencil hardness | F |
| Adhesion (ASTM D3359) | 5B |
| Dry to touch | 2–3 hours; dry to handle 4–6 hours |
| Full cure | 3–7 days |
| Topcoating | All Cortec High Performance Coatings can be topcoated over it; verify compatibility before applying solvent-based topcoats |
| Type | Water-based rust-converting primer with chelating agent; no tannic or phosphoric acid |
| Gloss (ASTM D523) | 4–10 |
| Recommended WFT | 8.3–13.9 mils (210–353 µm) |
| Viscosity | 900–2,000 cPs |
| Weight per gallon | 11.5 lb (1.38 kg/L) |
| Flash point | >200 °F (93 °C) |
| Dilution | Water, up to 15% by volume |
| Recoat / topcoat window | After 6 hours (dry to handle) |
| Force dry | 15–20 min at 150 °F (65 °C) |
| Surface preparation | SSPC-SP2 hand-tool cleaning; remove loose rust, oil and grease; applies over tight rust |
| Application temperature | 45–90 °F (7–32 °C), surface 5 °F above dew point |
| Metals | Ferrous only: carbon steel, stainless steel, cast iron. Not for aluminum, galvanized steel, copper, brass or solder |
| Consultation guide rating | 5 on carbon steel, stainless steel and cast iron; N/A on other metals |
| Cleanup | Water while wet; solvent-based paint stripper when dry |
| Storage | Original packaging, indoors, out of direct sunlight, 40–100 °F (4–38 °C); keep from freezing; shelf life 1 year |
| CE marking | Yes — CE marked (EN 1504 scope) per Cortec’s certified-products page |
| Size | 1 Gallon |
| Shipping weight | 12.5 lb (5.67 kg) |
| Availability | In stock |
| Cortec product number | 12402881 |
Solvent Recycling Systems is an authorized Cortec® distributor. See the full Cortec VpCI line, browse the VpCI product selection guide, or contact us for volume pricing and lead times.
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