Cortec publishes a one-page application guide for each of its VpCI coatings, and the guides all follow the same template: a physical-characteristics block, a surface-preparation and mixing block, spray-equipment settings, dry and cure times, and cleanup. That makes them easy to compare and hard to keep track of. This page puts the 28 guides Cortec issued for its high-performance coatings line side by side: one master comparison table, the shared application instructions written out once, a short note on what is specific to each product, and dedicated sections on removing the temporary coatings and on coating rusted steel without blasting. Where SRS stocks a product the name links to its listing; the rest are listed for reference. If you are choosing between coatings and packaging or a liquid rust preventative rather than between coatings, start with the VpCI product selection guide.
Three ways to sort the line
Temporary versus permanent. Cortec’s removable coatings (VpCI-368, 369, 372, 388, 389, 391 and the CorShield transit and strippable products) protect during shipping, outdoor storage or lay-up and then come off, by washing with a VpCI-414 solution or, for VpCI-372, by peeling. They are not painted over and do not cure hard; the wax and oil types stay soft and self-heal when scratched. The permanent coatings (primers such as CorrVerter, VpCI-373, 375, 395, 396; topcoats such as VpCI-386, 380, 382, 384; the tank lining VpCI-2026) cure to a hard film that is part of the finished product. In Cortec’s Product Consultation Guide, VpCI-368, 369, 388, 389, 391, 375, 383, 386 and 387 all carry a 4 (outside, uncovered) rating on every common metal; VpCI-395 and 396 are rated for immersion on ferrous substrates.
Water-based versus solvent-based. Cortec’s coatings training puts it plainly. Solvent-based products (VpCI-280, 368, 369, 371, 384, 396, 396Z, 398) tolerate low temperature and high humidity, forgive marginal surface preparation, and go over a light oil film. Water-based products (everything else here) have far lower VOC, clean up with water and avoid flash-point concerns, but need a cleaner substrate and are sensitive to cold and humidity during application and cure. Flash points in the table show the split: 40 °F for VpCI-280, 72 to 77 °F for the urethanes, above 200 °F for the water-based line.
One-component versus two-component. Most of the line is 1K. Four products are 2K with a mix ratio, sweat-in and pot life: VpCI-2026 (1 : 1.5, 20 to 25 minute pot life), VpCI-382 (2 : 1), VpCI-384 (3 : 1) and VpCI-395 (4 : 1), the last three with a 15 to 30 minute sweat-in and a 2 to 3 hour pot life. VpCI-396Z is a field mix of 31 lb of zinc per gallon of VpCI-396. Mix only what you will spray inside the pot life.
Master comparison table
All values are from Cortec’s published application guides. Spread rate is theoretical coverage at 1.0 mil dry film thickness, in square feet per gallon with square metres per litre in brackets; divide by your target DFT and allow for transfer loss. DFT and WFT are in mils. Dry to touch (DTT) and dry to handle (DTH) are at 70 °F and 50 percent relative humidity; force drying at 150 °F for 15 to 20 minutes is permitted for every product except VpCI-2026 and VpCI-369. Full cure is 3 to 7 days unless the recoat column says otherwise. Gloss is at 60° per ASTM D523.
| Product | Type | Vol. solids | Gloss | VOC lb/gal (g/L) | Viscosity | Spread rate ft²/gal (m²/L) | Wt/gal lb | Flash pt | DFT mils | WFT mils | DTT | DTH | Recoat |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CorrBarrier | WB primer | 44.3 % | 15–25 | 0.2 (24) | 5,000–10,000 cP | 710 (17.4) | 10.38 | >200 °F | 2.0–3.0 | 4.5–6.7 | 20–30 min | 1 hr | N/A |
| CorrVerter | WB rust-converting primer | 34.5 % | 15–25 | 0.1 (12) | 7,000–20,000 cP | 553 (13.6) | 11.59 | >200 °F | 3.0–5.0 | 8.7–14.5 | 2–3 hr | 4–6 hr | 6–72 hr, sand first |
| EcoPrimer | WB primer | 41.7 % | 15–25 | 0.1 (12) | 5,000–10,000 cP | 668 (16.4) | 11.75 | >239 °F | 1.5–4.0 | 3.6–9.6 | 20–30 min | 1 hr | 1–72 hr |
| EcoShield 386 | WB acrylic topcoat | 31 % | 80+ | 0.6 (72) | 51 s+ Zahn #3 | 497 (12.2) | 8.58 | >200 °F | 1.5–3.0 | 4.8–9.6 | 30 min | 1 hr | 1–72 hr |
| VpCI-2026 | 2K 100 % solids tank lining | 100 % | 80+ | 0.1 (12) | 2,200–3,000 cP | 50–125 at 11–13 mil (1.2–3) | 7.38 | >200 °F | 11–13 | 11–13 | 1.5–3.5 hr | 3.5 hr | 3.5–24 hr; full cure 24 hr; no force dry |
| VpCI-280 | SB alkyd topcoat | 54–57 % | 80+ | 2.8 (336) | 27–29 s Zahn #3 | 860–910 (21.1) | 8.5–10.4 | 40 °F | 1.0–3.0 | 2.0–6.0 | 30 min | 1 hr | 1–72 hr |
| VpCI-368 | SB temporary (waxy) | 52.3 % | N/A | 2.9 (347) | 68 s+ Zahn #3 | 838 (20.5) | 7.63 | 158 °F | 2.0–3.0 | 4.0–6.0 | 30 min | 60 min | N/A |
| VpCI-369 | Oil-based temporary (non-drying) | 99.2 % | N/A | 0 (0) | 50–70 s Zahn #3 | 1,588 (38.9) | 8.24 | 234 °F | 1.0–3.0 | 1.0–3.0 | N/A | N/A | N/A (no cure) |
| VpCI-371 | SB high-temperature silicone | 37.1 % | 80+ | 3.3 (395) | 30 s+ Zahn #3 | 593 (14.6) | 8.84 | 77 °F | 1.0–2.0 | 3.0–5.4 | 20 min | 40 min | 40 min–72 hr; heat cure 500 °F 30 min |
| VpCI-372 | WB peelable | 33.4 % | N/A | 0.2 (24) | 21–70 s Zahn #3 | 536 (13.2) | 8.85 | >200 °F | 2.0–10.0 | 6.0–30.0 | 1–2 hr | 2–3 hr | N/A |
| VpCI-373 | WB wash primer | 30.9 % | 15–25 | 0.6 (72) | 18–45 s Zahn #3 | 495 (12.1) | 10.17 | 130 °F | 0.5–1.0 | 1.6–3.3 | 20 min | 40 min | 40 min–72 hr |
| VpCI-375 | WB heavy-duty primer / one coat | 39 % | 30–50 | 0.7 (84) | 58 s+ Zahn #4 | 625 (15.3) | 10.42 | >200 °F | 1.5–3.0 | 3.8–7.7 | 20 min | 40 min | 40 min–72 hr |
| VpCI-380 | WB fluoropolymer topcoat | 44.3 % | 80+ | 1.6 (192) | 58 s+ Zahn #4 | 544 (13.4) | 8.79 | 150 °F | 3.0–5.0 | 8.8–14.7 | 30 min | 2 hr | 2–72 hr |
| VpCI-381 | WB urethane-acrylic topcoat, 1K | 33.7 % | 80+ | 0.29 (35) | 57 s+ Zahn #3 | 540 (13.3) | 8.65 | >200 °F | 1.5–3.0 | 4.4–8.9 | 20–30 min | 1 hr | 1–72 hr |
| VpCI-382 | WB urethane-acrylic topcoat, 2K | 67.9 % | 80+ | 0.02 (2.4) | 70 s Zahn #3 | 1,089 (26.7) | 11.23 | >200 °F | 1.5–3.0 | 2.2–4.4 | 2.5–3 hr | 5–6 hr | 6–72 hr |
| VpCI-383 | WB acrylic dip coat | 12 % | 85+ | 0.6 (72) | 22 s+ Zahn #2 | 197 (4.8) | 8.43 | >200 °F | 0.4–1.2 | 3.5–9.75 | 30 min | 1 hr | 1–72 hr |
| VpCI-384 | SB urethane topcoat, 2K | 50–55 % | 85+ | 3.5 (419) | 40–50 s Zahn #4 | 816 (20) | 9.33 | 72 °F | 1.5–3.0 | 3.0–6.0 | 30 min | 1.5–2 hr | 6–72 hr |
| VpCI-386 | WB acrylic DTM topcoat | 31 % | 80+ | 0.6 (72) | 51 s+ Zahn #3 | 497 (12.2) | 8.58 | >200 °F | 1.5–3.0 | 4.8–9.6 | 30 min | 1 hr | 1–72 hr |
| VpCI-387 | WB acrylic high-build topcoat | 30.9 % | 80+ | 0.8 (95) | 3,400–6,000 cP | 495 (12.1) | 8.58 | >200 °F | 3.0–5.0 | 9.0–16.0 | 1 hr | 2 hr | 2–72 hr |
| VpCI-388 | WB temporary | 26.7 % | N/A | 0.2 (24) | 5,000–15,000 cP | 428 (10.5) | 8.57 | >200 °F | 2.0–3.0 | 7.5–11.25 | 20–30 min | 45–60 min | N/A |
| VpCI-389 | WB temporary (waxy) | 37.1 % | N/A | 0.1 (12) | 5,500–10,000 cP | 595 (14.6) | 8.32 | >200 °F | 1.0–2.0 | 2.7–5.4 | 10–60 min | 20–60 min | N/A |
| VpCI-390 | WB alkyd topcoat | 26.2 % | 80+ | 1.12 (134) | 60 s+ Zahn #2 | 420 (10.3) | 9.83 | 117 °F | 1.5–2.0 | 5.75–7.6 | 1–2 hr | 2–3 hr | 3–72 hr |
| VpCI-391 | WB temporary (non-tacky) | 34.4 % | N/A | 0.4 (48) | 1,000–5,000 cP | 551 (13.5) | 8.32 | >200 °F | 1.0–3.0 | 2.9–8.75 | 30–60 min | 1–2 hr | N/A |
| VpCI-392 | WB urethane-dispersion topcoat | 34.1 % | 80+ | 1.1 (132) | 18 s+ Zahn #2 | 546 (13.4) | 8.34 | >200 °F | 1.0–2.0 | 2.9–5.8 | 30–40 min | 1–2 hr | 2–72 hr |
| VpCI-395 (Part B) | WB epoxy primer, 2K | 48.6 % | 15–25 | 0.2 (24) | 58 s+ Zahn #3 | 779 (19.2) | 11.88 | 122 °F | 1.5–3.0 | 3.0–6.0 | 20–30 min | 1–2 hr | 2–72 hr |
| VpCI-396 | SB moisture-cure urethane primer/topcoat | 56.2 % | 30–50 | 3.1 (371) | 57 s+ Zahn #3 | 901 (22.1) | 9.39 | 77 °F | 2.0–3.0 | 3.5–5.3 | 2–3 hr | 4–6 hr | 6–72 hr |
| VpCI-396Z | MCU zinc-rich primer/topcoat | 70.3 % | 15–25 | 2.1 (248) | 57 s+ Zahn #3 | 1,122 (27.5) | 24.34 | 77 °F | 2.0–3.0 | 3.5–5.3 | 1–2 hr | 2–3 hr | 3–72 hr |
| VpCI-398 | SB undercoat | 64.9 % | 15–25 | 2.6 (312) | 5,000–10,000 cP | 1,040 (25.5) | 5.9 | 106 °F | 4.5–5.0 | 5–7.7 | 4–6 hr | 8–10 hr | 6–72 hr |
Three notes on the table. EcoShield 386 and VpCI-386 are the same product under two names and their guides are data-identical. Cortec’s VpCI-372 guide prints the DFT as 12.5 to 25 µm, which does not match the mils column or the WFT; we show the mils figures and read the metric as a misprint for roughly 50 to 250 µm. The pre-diluted “D” versions of VpCI-368, 369 and 389 and the MIL-PRF-16173E Grade 1 version VpCI-368 M share the base product’s application guidance; they are linked in the per-product notes below.
General application instructions for Cortec coatings
This is the boilerplate common to all 28 guides, written out once so the per-product notes below can stay short.
- Surface. Free of grease, oil, dirt, fingerprints, drawing compounds, rust inhibitors and any other contaminant that would affect adhesion. For production lines, Cortec recommends a VpCI-440 or similar phosphatizing pretreatment. Structural steel is prepared to a minimum of NACE No. 3 / SSPC-SP6 commercial blast for every coating except CorrVerter, which is designed to go over hand-tool cleaned (SSPC-SP2) rusted steel. A VpCI-41x cleaner such as VpCI-414 or VpCI-416 handles the degreasing step and leaves a flash-rust inhibiting film that Cortec’s coatings adhere to.
- Wash primer. On aluminum, galvanized or plated substrates, apply VpCI-373 at 0.5 to 1.0 mil DFT first and test adhesion before committing. The per-product table marks which coatings call for it; the temporary coatings and VpCI-398 do not.
- Mixing. Power-agitate to a uniform consistency with a squirrel-cage or drill mixer. Reduce only with the stated diluent and only up to 10 percent by volume; VpCI-2026 is not reduced at all.
- Conditions. Apply between 45 and 90 °F (7 to 32 °C) with the surface at least 5 °F (2 °C) above the dew point. Moisture-cure urethanes (396, 396Z) need 20 to 80 percent relative humidity; VpCI-2026 needs below 75 percent.
- Methods. Spray, roll, brush or dip; VpCI-2026 is spray or roll only and VpCI-383 is formulated as a dip coat.
- HVLP or conventional spray. Fluid tip 0.009 to 0.021 in; 45 to 55 psi atomizing air, about 10 psi fluid pressure; 3/8 in ID fluid hose to a maximum of 50 ft; dual-regulated pressure pot at gun elevation.
- Airless or air-assisted. Tip 0.015 to 0.035 in; 1,800 to 2,500 psi; 3/8 in ID hose minimum (a 1/4 in whip is acceptable) to a maximum of 100 ft.
- Cleanup. Water for water-based products and butyl acetate for solvent-based products while wet; butyl cellosolve or MEK (MIBK for VpCI-2026, 389 and 391) once dry.
- Storage. Sealed container below 100 °F (38 °C); one-year shelf life. Water-based products must not freeze.
Product-specific application notes
Only the details that differ from the general instructions are listed. Diluent maximum is 10 percent by volume throughout.
VpCI-368
Solvent-based waxy temporary coating for extended outdoor storage; translucent, scratch resistant and self-healing; QPL listed. Diluent: mineral spirits. No wash primer needed. Not freeze sensitive. Wet cleanup with butyl acetate. Removal: see the VpCI-414 procedure below. Also available pre-diluted as VpCI-368 D, in a MIL-PRF-16173E Grade 1 grade as VpCI-368 M, and as the CorShield VpCI-368 aerosol for touch-up.
VpCI-369
Oil-based, non-drying temporary coating; oily translucent film, self-healing, zero VOC; QPL listed, MIL-PRF-16173E commercial equivalent. Diluent: mineral oil or mineral spirits (Cortec notes it can be cut with oil). No wash primer. Not freeze sensitive. No cure, so no force dry and no recoat window. Removal: VpCI-414 procedure. Pre-diluted version: VpCI-369 D; aerosol: CorShield VpCI-369.
VpCI-372
Water-based peelable coating; dries to a tack-free, rubbery film that protects against corrosion and surface damage. Applied thick (2 to 10 mils DFT) so it can be peeled as one sheet. Diluent: water. No wash primer. Freeze sensitive. Removal: peel; no cleaner or solvent.
VpCI-388
Water-based temporary coating, clear dry film for indoor and outdoor use; custom colors. Diluent: water. No wash primer. Freeze sensitive. Removal: VpCI-414 procedure.
VpCI-389
Water-reducible waxy temporary coating for outdoor storage; translucent, low VOC, custom colors. Diluent: water. No wash primer. Freeze sensitive. Dry cleanup with butyl cellosolve or MIBK. Removal: VpCI-414 procedure. Pre-diluted: VpCI-389 D; pump spray: EcoSpray 389.
VpCI-391
Water-based non-tacky temporary coating for medium to long-term indoor and outdoor protection; available in colors. Diluent: water. No wash primer. Freeze sensitive. Dry cleanup with butyl cellosolve or MIBK. Removal: hot water or an alkaline cleaner; the VpCI-414 procedure applies.
CorShield VpCI Transit Coating and EcoAir outdoor coating
CorShield Transit Coating is a zero-VOC water-reducible temporary coating positioned as a replacement for oil-based preventives in transit; the EcoAir biobased outdoor coating is a compressed-air aerosol for small parts and touch-up. Neither has a numbered application guide; follow the general instructions and the product data sheet.
CorrBarrier
Water-based primer. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive. Not recoat rated (single-coat primer under a topcoat).
CorrVerter
Water-based rust-converting primer with a chelating agent that converts remaining rust to a paintable surface. The one Cortec coating specified over SSPC-SP2 hand-tool cleaned steel rather than a blast. Ferrous only: the Product Consultation Guide rates it 5 on carbon steel, stainless and cast iron and not applicable on anything else. Applied heavy (3 to 5 mils DFT). Diluent: water. Freeze sensitive. Recoat 6 to 72 hours, sanding before the topcoat. See the rusted-steel system below.
EcoPrimer
Water-based primer, 1.5 to 4.0 mils DFT, flash point above 239 °F. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-373
Water-based wash primer, the adhesion layer for other Cortec coatings on aluminum, galvanized and plated substrates; replaces phosphate and chromate pretreatments and conforms to MIL-P-15328D as a bonding primer. Apply 0.5 to 1.0 mil only. Diluent: water. Freeze sensitive.
VpCI-375
Water-based heavy-duty acrylic primer that also serves as a one-coat primer and topcoat for harsh, unsheltered outdoor exposure. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-395
Two-component water-based epoxy primer, direct to metal, rated for immersion on ferrous substrates. Mix 4 parts A to 1 part B, sweat in 15 to 30 minutes, pot life 2 to 3 hours. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive. Flash point 122 °F. Part A is sold in white, clear and aluminum; Part B separately.
VpCI-396
Solvent-based, aluminum-filled moisture-cure urethane that works as a primer or a stand-alone primer/topcoat on structural steel, and tolerates marginal surface preparation. Diluent: xylol or t-butyl acetate. Wash primer on aluminum, galvanized or plated. Not freeze sensitive. Apply at 20 to 80 percent relative humidity. Purge partial containers with nitrogen before resealing; moisture in the headspace will start the cure. Topcoat with most conventional urethanes, including VpCI-384 or Cortec’s VpCI-394.
VpCI-396Z
Zinc-rich version of VpCI-396, field mixed at 31 lb of zinc per gallon of VpCI-396; 24.34 lb/gal mixed. Same diluent, humidity window and nitrogen-purge rule as VpCI-396.
VpCI-398
Solvent-based undercoat, applied at 4.5 to 5.0 mils DFT; slow drying (4 to 6 hours to touch, 8 to 10 to handle). Diluent: xylol or t-butyl acetate. No wash primer. Not freeze sensitive.
VpCI-280
Solvent-based alkyd topcoat with the lowest flash point in the line (40 °F); store and apply accordingly. Diluent: xylol or t-butyl acetate. Wash primer on aluminum, galvanized or plated. Not freeze sensitive.
VpCI-371
Solvent-based aluminum silicone coating for high-temperature service. Air dries in 20 to 40 minutes but requires a heat cure of 30 minutes at 500 °F to develop full properties. Diluent: xylol or t-butyl acetate. Wash primer on aluminum, galvanized or plated. Marked freeze sensitive in the guide.
VpCI-380
Water-based fluoropolymer topcoat, applied thicker than the acrylics (3 to 5 mils DFT). Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive. Flash point 150 °F.
VpCI-381
One-component water-based urethane-acrylic topcoat, very low VOC (0.29 lb/gal). Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-382
Two-component water-based polyurethane topcoat; high gloss, near-zero VOC (0.02 lb/gal), high solids. Mix 2 parts A to 1 part B, sweat in 15 to 30 minutes (pressure pot), pot life 2 to 3 hours. Longer dry (2.5 to 3 hours to touch). Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-383
Water-based acrylic clear dip coat at 12 percent solids for a thin (0.4 to 1.2 mil) UV-stable film; usable as a DTM primer or finish. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-384
Two-component solvent-based aliphatic polyurethane topcoat, typically over VpCI-396; no aromatic solvents. Mix 3 parts A to 1 part B, sweat in 15 to 30 minutes, pot life 2 to 3 hours. Diluent: xylol or t-butyl acetate. Wash primer on aluminum, galvanized or plated. Not freeze sensitive. Flash point 72 °F.
VpCI-386 and EcoShield 386
Water-based acrylic direct-to-metal primer/topcoat for harsh, unsheltered outdoor exposure; Cortec’s 2017 data cites 1,000 hours salt spray at 1 mil DFT. Weldable, UV resistant, available clear, white, black and aluminum; custom colors. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive. EcoShield 386 is the same formulation.
VpCI-387
High-build version of the 386 acrylic chemistry, 3 to 5 mils DFT per coat, for heat, humidity and salt-air exposure. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-390
Water-reducible alkyd topcoat suited to dip tanks; Cortec notes it is not a DTM coating for galvanized, aluminum or stainless. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive. Flash point 117 °F.
VpCI-392
Water-based urethane-dispersion topcoat, 1 to 2 mils DFT. Diluent: water. Wash primer on aluminum, galvanized or plated. Freeze sensitive.
VpCI-2026
Two-component, 100 percent solids tank-lining topcoat applied at 11 to 13 mils. Mix 1 part A to 1.5 parts B; pot life only 20 to 25 minutes. Do not reduce. Spray or roll only, below 75 percent relative humidity. Recoat between 3.5 and 24 hours; full cure 24 hours; no force drying. Dry cleanup with butyl cellosolve or MIBK.
How to remove VpCI-368, 369, 388, 389 and 391 temporary coatings
Cortec’s removal procedure is the same for all five washable temporary coatings and is built around VpCI-414, its cleaner formulated specifically to lift waxes and temporary coatings from bare metal and painted surfaces.
- Dilute VpCI-414 to 10 to 20 percent in water. Use the higher end for VpCI-368 and 369, which have the heaviest films, and for coatings that have weathered outdoors for a season or more. The refractometer target for 20 percent VpCI-414 is about 5.2 °Bx; see the concentration testing page.
- Apply the solution to the coated surface by spray, brush or dip and let it dwell for at least 15 minutes. VpCI-414 is viscous and clings to vertical surfaces, so it will stay in contact on machine frames and fabrications. Do not let it dry.
- Power wash with hot water, 120 to 180 °F, at 1,500 to 2,500 psi. The heat softens the wax or oil film and the pressure carries it off with the cleaner.
- Inspect and repeat on any areas that still show residue. Multiple coats or heavy DFT may need a second cycle.
- Because VpCI-414 leaves a flash-rust inhibiting film, the stripped surface does not need an immediate rust preventative if it is going straight to service or paint. For storage, follow with a VpCI-41x rinse or a water-based rust preventative.
VpCI-391 will also come off with hot water alone or any alkaline cleaner. VpCI-372 is not washed; it is peeled. The aerosol CorShield 368 and 369 films are removed the same way as the bulk products. For small parts, the same chemistry is available in the EcoAir VpCI-414 aerosol. Check seal and hose materials against the compatibility charts before running 414 through a parts washer or pressure washer; Cortec lists nitrile as not compatible with 414 at full strength.
Rusted steel system: CorrVerter, then VpCI-396 or 395, then topcoat
Not every rusted fabrication justifies a blast. For structural steel, tanks, frames and equipment that can be hand-tool or power-tool cleaned but not blasted, Cortec’s guides describe a three-layer system that starts on SSPC-SP2 steel.
- Clean and derust what you can. Degrease with VpCI-414 or 416, remove loose rust and scale with a wire brush or needle scaler to SSPC-SP2, and, if time allows, soak or brush the worst areas with VpCI-422 rust remover, rinse and neutralize with a 10 percent VpCI-414 or 416 solution. Do not let 422 dry on the surface.
- CorrVerter. Apply CorrVerter at 3 to 5 mils DFT over the tightly adherent rust that remains. Its chelating chemistry converts that rust to a stable, paintable layer. Allow 2 to 3 hours to touch, 4 to 6 to handle, and recoat within 6 to 72 hours after a light sand. Ferrous substrates only.
- Barrier primer. For outdoor or immersion service, follow with VpCI-396 moisture-cure urethane (solvent based, forgiving of humidity and cold, 2 to 3 mils, recoat 6 to 72 hours) or VpCI-395 two-component water-based epoxy (low VOC, 1.5 to 3 mils, recoat 2 to 72 hours). VpCI-396 can also stand alone as a primer/topcoat where appearance is secondary.
- Topcoat. Finish with VpCI-386 acrylic for a low-VOC, UV-resistant finish in color, or VpCI-384 two-component urethane over VpCI-396 where gloss and chemical resistance matter. Respect the recoat windows in the table; if a window is missed, scuff-sand before the next coat.
The system trades some ultimate service life for a large saving in surface preparation, and Cortec’s training makes the same point about coatings generally: compare applied cost (volume solids, DFT and preparation) rather than price per gallon.
When to blast instead
The rusted-steel system is for tight rust on steel you cannot economically blast. Blast when the specification calls for SSPC-SP6 or better, which is the baseline for every Cortec coating except CorrVerter; when heavy scale, pitting or old coating would defeat a converter; when the part is going into immersion or continuous condensation service; or when the asset value justifies the longest coating life. For shops running that volume, an enclosed blast room with media recovery is the efficient way to reach SP6 or SP10 repeatedly; our blast rooms are engineered to your part size and throughput and pair with the workflow in our clean-then-protect article. Freshly blasted steel rusts within hours in a humid shop, so plan the primer, or at least a VpCI-41x rinse or VpCI-377 hold coat from the rust prevention category, into the same shift.
Frequently asked questions
What is the difference between VpCI-368 and VpCI-369?
Both are outdoor-rated, self-healing temporary coatings. VpCI-368 is solvent based and dries to a waxy, scratch-resistant film in about an hour; VpCI-369 is oil based, zero VOC, and never dries, leaving an oily film that also lubricates. Choose 368 where the part will be handled and 369 where it will sit, or where an oily film is acceptable and VOC is not.
Which Cortec coatings are two-component?
VpCI-2026 (1 : 1.5), VpCI-382 (2 : 1), VpCI-384 (3 : 1) and VpCI-395 (4 : 1). VpCI-396Z is a field mix of zinc into VpCI-396. All the others are single component.
Do I need VpCI-373 wash primer?
Only on aluminum, galvanized or plated substrates, and only under the permanent coatings. The temporary coatings (368, 369, 372, 388, 389, 391) and VpCI-398 go on without it. Test adhesion on a sample first.
How many square feet will a gallon of VpCI-386 cover?
Cortec’s theoretical spread rate is 497 ft²/gal at 1.0 mil DFT. At the recommended 1.5 to 3 mils that is roughly 165 to 330 ft²/gal before transfer loss. Use the same arithmetic for any product in the table.
Can I paint over VpCI-377 or VpCI-368?
VpCI-377 rust preventative is designed to be painted over without removal. The temporary coatings are not: VpCI-368, 369, 388, 389 and 391 must be washed off with VpCI-414 before any coating is applied.
Can the water-based coatings be stored in an unheated warehouse?
No. Every water-based Cortec coating is marked freeze sensitive and must be kept above freezing. Solvent-based products (280, 368, 369, 384, 396, 396Z, 398) are not freeze sensitive but should still be stored below 100 °F with a one-year shelf life.
Why does VpCI-396 need a nitrogen purge?
It cures by reacting with moisture. Humid air in a partly used container will begin to cure the product in the can; purging the headspace with nitrogen before resealing prevents that.
Want the original Cortec application guide PDF for a specific coating, or help specifying a system for a rusted fabrication, a paint line or an outdoor lay-up? Contact Solvent Recycling Systems. Related guides: VpCI concentration testing for the VpCI-414 removal bath, how to shrink wrap equipment with MilCorr for combining temporary coatings with film, and the full Cortec product category.
Data source: compiled from Cortec application guides and technical literature (28 Cortec coatings application guides, the Cortec product brochure and Product Consultation Guide, and Cortec coatings training material, 2013–2017 vintage); confirm against the current product data sheet before specifying.
