Cortec makes several hundred VpCI products, and most of them protect “multiple metals” in “a range of environments.” That is true and not very helpful when you have a pallet of machined castings going into unheated storage for eight months, or a copper-wound motor going to a port. This guide condenses Cortec’s own Product Consultation Guide, the only place Cortec ranks its whole line on one scale, into tables you can actually use to pick a product. Every rating below is Cortec’s published data. Where a product is stocked by Solvent Recycling Systems, the name links to its listing.
How to use this guide
Start with two questions: what metal (or mix of metals) am I protecting, and how severe is the exposure? Cortec answers both with a single matrix. Each product is rated against nine metal columns (carbon steel, stainless steel, cast iron, aluminum alloys, galvanized steel, copper, brass under 30 percent zinc, solder, and epoxy-coated steel) and the cell holds a number from 1 to 5 that says how harsh an environment the product can handle on that metal. The tables below give each product’s highest rating and the metals it carries that rating on. If your metal is listed and your environment number is at or below the product’s rating, the product is a candidate. Then read the notes column, because a handful of products carry explicit do-not-use warnings.
The 1 to 5 environment severity ladder
Cortec’s key is cumulative: a product rated 3 also covers everything at 1 and 2.
- 1 – Enclosed. Non-ventilated equipment housings, control boxes, or other enclosures; parts packaged in cardboard, paper, plastic wrap, or metal containers. This is where emitters, foams, tablets and pouches live, because they only work inside a sealed space.
- 2 – Inside. Adds uncovered indoor storage. Most VpCI films, papers, water-based rust preventatives and cleaners with short-term protection sit here.
- 3 – Outside sheltered. Adds outdoor storage under a roof or cover. Oil-based concentrates and some electronics sprays reach this level.
- 4 – Outside. Adds uncovered outdoor storage. Temporary coatings, several permanent coatings, and one packaging film (MilCorr) are rated here.
- 5 – Immersion. Adds immersion service in corrosive liquids such as salt water or crude oil. Water-treatment additives, hydrotest powders, oilfield inhibitors and the immersion-grade primers are the only products rated 5.
Two more symbols appear in the guide. A check mark means “safe to use on the metal; consult Cortec for application information,” and it is used for additives, cleaners and rust removers that are not themselves rated as protectors. An asterisk means “caution, do not use with the indicated metal.” N/A means not recommended or no test data.
How VpCI works, in one paragraph
VpCI is Cortec’s trademark for its vapor phase corrosion inhibitor chemistry, much of it amine-carboxylate. The molecules have a charged side that adsorbs to metal and a hydrophobic side that faces outward, so a few molecular layers form a water-repelling film. In a package or void, the inhibitor evaporates, diffuses until the enclosed air is saturated, and condenses on every metal surface it can reach, including recesses and threads. The layer re-heals through further condensation as long as the source is present and the space stays sealed. Coatings and oils work mostly by contact; films and papers work by contact and vapor; emitters work by vapor alone. That last distinction matters when you choose a product: an emitter in an open crate does very little.
What VpCI cannot do
- It does not reverse rust that is already there. Rust removers like VpCI-422 and VpCI-426 do that job first; the inhibitor keeps clean metal clean.
- It does not work by drying the air. Desiccants are passive and VpCI is active; Cortec sells combination pouches (Desicorr VpCI) precisely because they do different things.
- It needs reasonably clean metal. Dust, dirt and grease block adsorption, which is why Cortec’s surface-prep standard for its liquids and coatings is SSPC-SP-1.
- Vapor-phase products need a seal. Cortec describes the spectrum plainly: an open package gives minimal protection, a frequently opened or poorly sealed one gives some protection with shorter emitter life, and a well-sealed one gives maximum protection and service life.
Packaging: films, papers, foams, emitters and pouches
Almost everything in this family is rated 1 or 2, because packaging protects the metal inside the package, not the package itself. The exception is MilCorr shrink film, the only packaging product Cortec rates for uncovered outdoor exposure. Full wrapping instructions are on the MilCorr shrink-wrap guide.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-101, VpCI-105, VpCI-111 emitters | Electrical enclosures, control boxes, sealed crates | All metals in the guide | 1 – Enclosed | One VpCI-101 per 1 cu ft; VpCI-105 covers 5 cu ft; VpCI-111 covers 11 cu ft. Must be inside a closed space. |
| VpCI-131, VpCI-132, VpCI-133, VpCI-136, VpCI-137 foams; VpCI-170 tape | Precision parts and electronics that also need cushioning or static control | All metals in the guide | 1 – Enclosed | Static dissipative; meets MIL-PRF-81705D for ESD. Nitrite free. |
| BioPad, BioBoard, Eco Emitter | Biobased emitter inserts for boxes and crates | All metals in the guide | 1 – Enclosed | Non-woven or board carriers; same sealing rule as any emitter. |
| Cor-Pak 1-MUL pouches, Cor-Pak tablets, VpCI-308 pouches, EcoPouch | Voids where loose powder is not acceptable; tool boxes, shipping cases | All metals in the guide (pouch devices rated 1); VpCI-308 powder itself is rated 5 | 1 – Enclosed as packaged devices | Tablets conform to MIL I-22110C. The Tyvek pouch keeps powder off the parts. |
| Desicorr VpCI | Export packs where humidity control and VpCI are both wanted | All metals in the guide | 1 – Enclosed | Two-in-one desiccant plus VpCI pouch. Unopened shelf life up to 24 months or until color change. |
| VpCI-126 Blue bags, tubing, gusseted bags | General multimetal bagging for indoor storage and shipping | All metals in the guide | 2 – Inside | Heat sealable; conforms to MIL-PRF-22019D and MIL-B-22020D. Shrink-film version available for indoor wrapping. |
| VpCI-125 / EcoSonic 125 HP ESD bags | Circuit boards, sensors, anything static sensitive | All metals in the guide | 2 – Inside | Meets MIL-PRF-81705D for ESD. Combines VpCI, static dissipation and, in VpCI-125, desiccant properties. |
| VpCI-146 kraft paper, VpCI-144 barrier paper, VpCI-145, VpCI-148, VpCI-149, EcoSonic ESD paper | Wrapping, interleaving, sheet liners | All metals in the guide | 2 – Inside | VpCI-144 replaces polyethylene-coated paper and is repulpable. VpCI-149 is Cortec’s choice for sensitive metals such as copper, aluminum and cast iron. |
| Corrosorber paper | Silver, gold, tin, copper and brass parts | Copper, brass, solder only | 2 – Inside | N/A on ferrous metals. Scavenges corrosive gases rather than emitting VpCI. |
| Cor-Pak bubbles, Cor-Pak stretch film, Cor-Pak EX film, Cor-Pak linerboard and corrugated | Cushioning, pallet wrapping, box liners | All metals in the guide | 2 – Inside | Stretch film leaves no residue. Cor-Pak EX is 1.25 mil HDPE. |
| EcoWeave woven polyethylene, EcoShield fabric and paper, Eco-Corr film | Heavy or sharp-edged parts; compostable packaging programs | All metals in the guide (Eco-Corr film N/A on solder) | 2 – Inside | EcoWeave is the tear-resistant choice. Eco-Corr is BPI-certified compostable. |
| CorrLam barrier laminate | Vacuum packaging of moisture- or oxygen-sensitive parts | All metals in the guide | 2 – Inside | Foil/VpCI polyethylene laminate; MIL-PRF-131J commercial equivalent. |
| MilCorr VpCI shrink film | Outdoor shrouding of equipment, deck cargo, long-term yard storage | All metals in the guide | 4 – Outside | 10 mil, UV stabilized. The only packaging film rated for uncovered outdoor storage. |
Water-based rust preventatives and metalworking fluids
Cortec rates its water-based liquids at 2, indoor storage. That is not a weakness; these are the products that replaced oily coatings in most plants because they leave a dry, clear, paintable film and rinse off with water. Concentration controls how long they protect, which is why the refractometer and pH testing guide matters as much as the product choice.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-377 (also 377 D ready to use, EcoAir 377 aerosol) | Direct replacement for oil-based RPs on multimetal parts; dip or spray | All metals in the guide | 2 – Inside | 2–5 percent gives up to 1 year indoors, 5–10 percent up to 2 years, 10–20 percent may exceed 2 years with noticeable tackiness. Can be painted over without removal. |
| BioCorr | Ready-to-use, zero-VOC dip or spray for machined ferrous parts and aluminum | Carbon steel, stainless, cast iron, aluminum, galvanized | 2 – Inside (Cortec: aggressive indoor and mild outdoor) | Up to 2 years plus indoors. Not intended for yellow metals (copper, brass). Keep the tank covered and agitated; cleaner carry-over destabilizes the emulsion. |
| VpCI-316 | Copper, brass and other yellow metals | Formulated for yellow metals; rated 2 across the guide | 2 – Inside | Same dilution ladder as VpCI-377. Dries to a transparent film; also lubricates and cools in processing. |
| VpCI-379 | Long-term indoor storage and shipping where a paintable dry film is wanted | All metals in the guide | 2 – Inside | Multimetal; military stock number listed. Water-based replacement for oil chemistries. |
| VpCI-378 | Water-emulsifiable RP that doubles as a quenching fluid | All metals in the guide | 2 – Inside (Cortec: indoor and sheltered outdoor) | Forms a stable emulsion in water. |
| VpCI-337 (also EcoAir 337 fogger) | Fogging the inside of pipes, tanks, vessels, heat exchangers; edge spray | All metals in the guide | 2 – Inside (sealed void) | About 1 oz per cu ft of void. Vapors travel up to 100 ft through piping. Up to 2 years if the void stays sealed and dry. |
| VpCI-338 | Edge treating coil and sheet stacks; fogging enclosures | Especially ferrous, aluminum, tin plate | 2 – Inside | FDA approved for indirect food contact. |
| VpCI-344, VpCI-345, VpCI-347 | Wet tempering of galvanized and cold-rolled steel (344); machining and grinding coolant (345); drawing, broaching, stamping lubricant (347) | All metals in the guide | 2 – Inside | In-process fluids with built-in corrosion protection; VpCI-347 works at dilutions down to 1:40. |
| CorShield VpCI transit coating | Water-reducible replacement for oil-based preventives on equipment in transit | All metals in the guide | 4 – Outside | Rated alongside the temporary coatings even though it is water-based. |
| EcoLine cutting fluid, EcoLine cleaner/degreaser | Soy-based biodegradable process fluids | Cutting fluid N/A on brass and solder; cleaner N/A on solder | 2 – Inside | Temporary protection only; follow with an RP or packaging for storage. |
Oil-based rust preventatives and oil additives
Oil-based concentrates are rated 3, sheltered outdoor, one step above the water-based line. They protect by contact and, because they carry VpCI, in the vapor space above the oil level in a gearbox or hydraulic reservoir. Before adding any of them to a system oil, check the oil and elastomer compatibility charts.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-322 | Additive to lubricating systems for operation and lay-up; can be fogged into cavities | All metals in the guide | 3 – Outside sheltered | MIL PRF-46002C commercial equivalent. Typical addition rates in the compatibility chart run 10–20 percent depending on the base oil. |
| VpCI-323 | Engine systems, operating and lay-up | All metals in the guide | 3 – Outside sheltered | Higher-flashpoint version (323M) available. |
| VpCI-325 (also EcoSpray 325) | Finely machined, honed or mirror finishes; gun barrels | All metals in the guide | 3 – Outside sheltered (EcoSpray 325 rated 2) | Ready-to-use vegetable oil base. MIL C-81309 commercial equivalent. |
| VpCI-326 | Hydraulic systems | All metals in the guide | 3 – Outside sheltered | Passes through a 1-micron filter, which is why it is the hydraulic choice. |
| VpCI-327 | Solvent-based indoor RP that also lifts fingerprints and stains | All metals in the guide | 3 – Outside sheltered | MIL C-15074E and MIL C-81309 commercial equivalents. |
| VpCI-329 (also VpCI-329 D ready to use) | Gearboxes, crankcases and lubrication systems; 329 D for dip, spray or brush on parts | All metals in the guide | 3 – Outside sheltered | 329 D is pre-diluted 1:9 in naphthenic oil; do not dilute further. Cortec: up to 2 years, outdoor storage not recommended. Surfaces must be dry. |
| VpCI-330 | Clear, low-viscosity ready-to-use oil RP | See data sheet | Not listed in the 2013 consultation guide | Newer product; confirm ratings on the current data sheet. |
| M-529, M-530, M-531, M-535 | Additive packages for engine, hydraulic, gear and turbine oils (M-530 includes a demulsifier; M-535 is ashless) | Check mark, all metals | Additive; consult Cortec | Compatibility is oil-specific. Chart addition rates run 2–15 percent by base oil; see the compatibility hub. |
| VpCI-705 | Gasoline and diesel storage tanks, intermittent-use engines | All metals in the guide | 5 – Immersion | 0.1–0.15 percent by volume in fuel; fog empty tanks for storage. |
| CorrLube VpCI lithium EP grease | Bearings, slides and fittings exposed outdoors | Ferrous, aluminum, galvanized | 4 – Outside | Other CorrLube fluids (hydraulic, gear oil, motor oils) are rated 2. |
| EcoLine ELP and other EcoLine lubricants | Biobased penetrant and lubricant with corrosion inhibition | EcoLine all-purpose lube rated on ferrous, aluminum, galvanized | 2 – Inside | Confirm the current product’s rating; the 2013 guide lists the earlier EcoLine names. |
Temporary (removable) coatings
This is the family for uncovered outdoor storage: rated 4 across the board. They leave a waxy, oily or dry film that is removed later with a solvent, hot water or alkaline cleaner. Application details, film builds and removal are in the coatings application guides.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-368 (also 368 D, 368 M, aerosol) | Extended outdoor storage of multimetal equipment | All metals in the guide | 4 – Outside | Solvent-based; translucent waxy film, scratch resistant and self-healing. Remove with common solvents or VpCI-414. |
| VpCI-369 (also 369 D, aerosol) | Outdoor storage where an oily, self-healing film is acceptable; doubles as a lubricant | All metals in the guide | 4 – Outside | Oil-based; can be diluted with oil. MIL PRF-16173E commercial equivalent. |
| VpCI-372 strippable coating; CorShield strippable | Physical protection plus corrosion protection; peel to remove | All metals in the guide | 3 – Outside sheltered | Dries to a tack-free rubbery skin. |
| VpCI-388 | Clear, dry, low-VOC water-based temporary coating | All metals in the guide | 4 – Outside | Custom colors available. |
| VpCI-389 (also 389 D, EcoSpray 389) | Outdoor storage with a water-reducible, low-VOC waxy coating | All metals in the guide | 4 – Outside | Dilutable with water; easily removable. EcoSpray 389 is also rated 4. |
| VpCI-391 | Medium- to long-term indoor and outdoor storage where a non-tacky film is needed | All metals in the guide | 4 – Outside | Removed with hot water or alkaline cleaner. |
| EcoLine 3690 | Biobased ready-to-use coating for severe marine and high-humidity conditions | All metals in the guide | 3 – Outside sheltered | Biodegradable. EcoLine rust preventative is also rated 3 but on ferrous, aluminum and galvanized only. |
| EcoLine 3220 | Canola-based contact and vapor protection in storage and shipment | All metals in the guide | 2 – Inside | 100 percent biobased, ready to use. |
Permanent coatings
Cortec’s permanent coatings replace sacrificial-metal pigments with organic inhibitors. The two moisture-cure and epoxy primers are the only coatings rated 5, immersion. Note that the copper, brass and solder columns are N/A for the whole family; these are steel and aluminum coatings.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-371 | High-temperature surfaces, to 1,200°F | See data sheet | Not individually listed in the 2013 consultation guide | Aluminum silicone coating; confirm on the current data sheet. |
| VpCI-373 wash primer | Replacement for phosphate and chromate pretreatments | All metals in the guide | 3 – Outside sheltered | Conforms to MIL P-15328D as a bonding primer. |
| VpCI-374 acrylic primer | Salt-resistant latex primer under water- or solvent-based topcoats | All metals in the guide | 4 – Outside | Hydrophobic; topcoat with most finishes. |
| VpCI-375 one coat | Harsh, unsheltered outdoor exposure with one product as primer and topcoat | All metals in the guide | 4 – Outside | Water-based acrylic; keep from freezing. |
| VpCI-383 thin film | Clear acrylic direct-to-metal or finish coat | All metals in the guide | 4 – Outside | UV stable, medium to high gloss. |
| VpCI-386 / EcoShield 386 (also 386 Aluminum) | Water-based acrylic primer/topcoat for harsh outdoor service | All metals in the guide | 4 – Outside | Cortec: competes with most paints and zinc-rich primers. Aluminum-pigmented version adds UV and abrasion resistance. |
| VpCI-387 high build | Heat, humidity and salt air | All metals in the guide | 4 – Outside | |
| VpCI-394 moisture-cure urethane topcoat; CorShield Gold | Topcoat over VpCI-396 on marginally prepared structural steel | Ferrous, aluminum, galvanized; N/A copper, brass, solder | 4 – Outside | Apply VpCI-394 over VpCI-396. |
| VpCI-395 2K water-based epoxy primer | Highest-performance primer in most environments, including immersion | Ferrous, aluminum, galvanized; N/A copper, brass, solder | 5 – Immersion | Two-component kit (Part B sold separately). Spray, brush or roll. |
| VpCI-396 moisture-cure urethane primer | Structural steel, including surfaces that cannot be blasted to white metal | Ferrous, aluminum, galvanized; N/A copper, brass, solder | 5 – Immersion | Aluminum filled; hard, flexible; topcoat with most urethanes. The conductive version is rated 4. |
| CorrVerter rust converter primer | Painting over rusted steel without full rust removal | Carbon steel, stainless steel, cast iron only; N/A all other metals | 5 – Immersion | Chelating agent converts rust to a paintable surface. Ferrous metals only. |
Cleaners, degreasers and rust removers
Cleaners are rated for the short-term flash-rust protection they leave behind (1 or 2), and rust removers get a check mark meaning “safe on this metal.” The metal columns are where the cautions hide, so read them before you put a mixed-metal load in a dip tank or a parts washer. The clean-then-protect article covers how these pair with rust preventatives, and the full range is in the cleaners and degreasers category.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VpCI-408 | Foam-free, neutral-pH cleaner for high-pressure and spray parts washers | All metals in the guide | 1 – Enclosed (short-term protection) | Light to medium oils; short-term protection after cleaning. |
| VpCI-411 / 411 Gel | D-limonene degreasing, gel for vertical surfaces | All metals in the guide | 1 – Enclosed | Flash-rust protection only. |
| VpCI-414 (also EcoAir 414) | Removing temporary coatings (368/369/389/391), waxes, heavy grease | All metals in the guide | 1 – Enclosed | Strongest cleaner in the line. Cortec advises against long exposure of yellow metals. |
| VpCI-415 | Aircraft and general degreasing where MIL-PRF-87937D and biodegradability matter | All metals in the guide | 2 – Inside | Heavy-duty alkaline; readily biodegradable. |
| VpCI-416 (also EcoSpray 416) | Neutralizing after acid cleaning or pickling; best post-clean protection of the cleaners | All metals in the guide | 2 – Inside | Cortec: up to 6 months indoor protection after cleaning. Stable through freeze-thaw. |
| VpCI-417 powder | Power washers and ultrasonic tanks | All metals in the guide | 2 – Inside | Low foaming; available in water-soluble 5 lb charges. |
| VpCI-418 L, VpCI-418 LM, VpCI-418 powder | Non-foaming cleaner for industrial spray washers | All metals in the guide | 2 – Inside | 418 LM is the sodium- and silicate-free, no-residue version. |
| VpCI-419 | Foaming cleaner for industrial, oilfield, refinery and marine equipment; best cast-iron protection | Carbon steel, stainless, cast iron, aluminum only | 2 – Inside | N/A on galvanized steel, copper, brass and solder. |
| VpCI-422 / VpCI-423 gel (also EcoAir 422, EcoClean 423) | Organic rust and tarnish removal that will not attack the base metal | Check mark on all metals except aluminum (N/A) | Rust remover; consult Cortec | Soak 15 minutes for light rust to 1 hour plus for heavy. Rinse, then dip in a VpCI cleaner to stop flash rust. |
| VpCI-425 neutral rust remover powder | Low-dosage removal of rust, oxidation and scale | Ferrous and aluminum; N/A galvanized, copper, brass, solder | Rust remover; consult Cortec | |
| VpCI-426 (liquid, gel, powder) | Heavy-duty rust, scale and oxidation removal from virtually any metal | Check mark on all eight metals | Rust remover; consult Cortec | Cortec singles out aluminum, carbon steel, stainless steel and copper as where it is especially effective. |
| VpCI-427 | Dissolving oxides and scale from aluminum | Aluminum only | Cleaner; consult Cortec | |
| VpCI-429 | pH-neutral rust removal on mixed-metal assemblies | Check mark on all eight metals | Rust remover; consult Cortec | Prevents further rusting during the cleaning process; no neutralization step. |
| VpCI-432 / 433 paint strippers | Alkyd, acrylic and urethane removal | Ferrous, aluminum, galvanized; N/A copper, brass, solder | Stripper; consult Cortec | 433 is the gel. |
| VpCI-440 | Pretreatment replacing phosphatizing and chromating | All metals in the guide | 2 – Inside | |
| Corwipe 300, Corwipe 500 | Wipe-down of tools, molds and parts before packaging | All metals in the guide | 1 – Enclosed | Removes oil, grease and light rust; leaves an antistatic film. |
Water treatment products and VpCI powders
These are the immersion-grade products. Powders are dusted or fogged into voids, dissolved into hydrotest water, or dropped into boilers in water-soluble bags. The water treatment liquids are the only Cortec products routinely rated 5 across every metal column.
| Product | Best for | Metals | Highest environment rated | Notes and cautions |
|---|---|---|---|---|
| VmCI-307 | Dusting or fogging voids where a low depletion rate is wanted | All metals in the guide | 3 – Outside sheltered | Low water solubility. Meets MIL I-22110C. |
| VpCI-308 (powder; see pouches above) | Fast-acting multimetal fogging of enclosures and piping | All metals in the guide | 5 – Immersion | High volatility and water solubility; about 0.5 oz per cu ft of void. |
| VpCI-309 / 309 SF / 309 pouch | Ferrous voids, boilers and tanks where copper components are present | Ferrous, aluminum, galvanized | 3 – Outside sheltered | Cortec notes it is not aggressive to copper and yellow metals, unlike VpCI-609. |
| VpCI-609 (also 609 S anti-clumping) | Wet or dry lay-up of ferrous equipment and aluminum; hydrotest water | Ferrous, aluminum, galvanized | 5 – Immersion | Caution: do not use with copper or brass. N/A on solder. Cortec describes it as high volatility and possibly aggressive to yellow metals. |
| VpCI-608 | Double bottoms of storage tanks | Ferrous, aluminum, galvanized | 3 – Outside sheltered | |
| VpCI-611 | Hydrotesting, wet blasting and flash-rust prevention on ferrous metals | All metals in the guide | 5 – Immersion | |
| VpCI-641, VpCI-644, VpCI-645, VpCI-649 | Closed loops and hydrotesting (641); brines and chloride water (644); seawater and sulfide-bearing water (645); low-dosage closed-loop cooling (649) | All metals in the guide | 5 – Immersion | VpCI-649 also comes as a powder. |
| VpCI-615, VpCI-617 | Low- to medium-pressure boiler protection and scale control | All metals in the guide | 5 – Immersion | Phosphonate based. |
| Boiler Lizard, Cooling Tower Frog | Dry lay-up of boilers and cooling towers | All metals in the guide | 3 – Outside sheltered | VpCI powder in water-soluble PVA bags. |
| Cooling Loop Gator, Closed Loop Toad | Seasonal lay-up and operating closed cooling systems | All metals in the guide | 5 – Immersion | PVA bags; drop in and circulate. |
| M-645 | Ballast tanks, offshore platforms, hydrotesting in seawater | Check mark, all metals | Additive; consult Cortec | |
| M-640 / 640L | Water and glycol engine coolants | Check mark, all metals | Additive; consult Cortec | Passes ASTM D-1384 glassware test. |
Choose by situation
Indoor storage, under 6 months
For clean, dry parts going onto a shelf or into a box, VpCI-126 Blue bags or VpCI-146 paper alone are usually enough. If the parts come out of a washer, a final dip in VpCI-416 at 5 to 10 percent gives up to six months indoors with no separate RP step. For bare-metal shelving, VpCI-377 at 2 to 5 percent leaves an almost invisible film good for up to a year.
Indoor storage, 6 to 24 months
BioCorr ready to use (ferrous and aluminum, up to two years plus), VpCI-377 or VpCI-316 at 5 to 10 percent (up to two years), or VpCI-329 D where an oil film is acceptable (up to two years). Pair any of them with a VpCI-126 bag and a Desicorr VpCI pouch for the full term.
Export and ocean shipping
Seal the metal in VpCI-126 Blue or EcoWeave for heavy or sharp parts, add Desicorr VpCI for the humidity swings, and apply BioCorr or VpCI-377 under the film if the transit is long or the parts are high value. For deck cargo or equipment that will sit in a yard at the destination, shroud in MilCorr and treat fuel, oil and hydraulic voids with VpCI-705, VpCI-322 or VpCI-329 first. CorShield transit coating is the water-based option rated for outdoor transit.
Outdoor, uncovered
Coat with VpCI-368 (waxy, solvent-based), VpCI-369 (oily, also a lubricant) or VpCI-389 (water-reducible, low VOC), then shroud in MilCorr if you can. Electrical gear and connections outdoors get ElectriCorr VpCI-239. None of the water-based rust preventatives are rated for this exposure.
Immersion, hydrotest and wet lay-up
VpCI-609 dissolved in the hydrotest water protects ferrous vessels and aluminum during the test and after draining, but not if copper or brass is in the circuit; there, use VpCI-611, VpCI-641 or M-645 (seawater). For permanent coatings that will see immersion, VpCI-395 and VpCI-396 are the two rated 5.
Electronics and electrical enclosures
Drop VpCI-101 or VpCI-111 emitters into cabinets (one per 1 or 11 cu ft), spray contacts and boards with ElectriCorr VpCI-238 indoors or VpCI-248 for sheltered marine and tropical exposure, and pack boards in VpCI-125 ESD bags or VpCI-131 foam. VpCI-286 is the conformal coating. None of these alter electrical resistance or magnetic properties, per Cortec.
Copper and brass
Use VpCI-316 as the liquid RP, VpCI-146 or VpCI-149 paper for wrapping, and VpCI-426 or VpCI-429 for tarnish and scale. Do not use VpCI-609, BioCorr or VpCI-419, and keep VpCI-414 contact short.
Aluminum
VpCI-377, BioCorr and VpCI-379 all carry aluminum in their ratings; VpCI-386 Aluminum is the outdoor coating. For oxide and scale removal use VpCI-426 or VpCI-427 (aluminum only). Do not use VpCI-422 or VpCI-423 on aluminum.
Galvanized steel
VpCI-344 for wet tempering in process, VpCI-377 or VpCI-379 for storage, VpCI-368 or VpCI-369 outdoors. Do not use VpCI-419 or VpCI-425 on galvanized; VpCI-426 and VpCI-429 are the rust removers that carry a check on it.
Cautions worth memorizing
- CorrVerter is rated for carbon steel, stainless steel and cast iron only. Every other metal column is N/A.
- VpCI-609 carries Cortec’s explicit do-not-use caution on copper and brass, and is N/A on solder. Use VpCI-309 or VpCI-611 where yellow metals are present.
- VpCI-422 and VpCI-423 are N/A on aluminum. Use VpCI-426, 427 or 429 instead.
- VpCI-419 is N/A on galvanized steel, copper, brass and solder.
- BioCorr is not intended for yellow metals (copper, brass). VpCI-316 is the water-based RP for them.
- VpCI-425 is N/A on galvanized, copper, brass and solder; VpCI-427 is aluminum only.
- Permanent coatings (VpCI-394, 395, 396, CorrVerter, CorShield Gold) are N/A on copper, brass and solder.
- VpCI-329 D and the other oil-based liquids are rated 3, sheltered; Cortec does not recommend them for uncovered outdoor storage.
The remaining hubs in this series fill in the “how”: refractometer and pH concentration testing for the water-based RPs and cleaners, the coatings application guides for film builds and removal, the oil and elastomer compatibility charts for anything you add to a system fluid, and the MilCorr shrink-wrap guide for outdoor shrouding. The complete stocked range is in the Cortec category and the rust prevention category.
Frequently asked questions
What do the numbers 1 through 5 mean on a Cortec product rating?
They are Cortec’s environment severity scale from the Product Consultation Guide: 1 enclosed, 2 inside, 3 outside sheltered, 4 outside uncovered, 5 immersion. The scale is cumulative, so a product rated 4 is also suitable for 1, 2 and 3. The rating is given per metal, so the same product can be 5 on carbon steel and N/A on brass.
Which Cortec rust preventative is best for mixed steel and copper parts?
For a liquid, VpCI-377 carries every metal in the guide at rating 2 and is the safest multimetal choice; VpCI-316 is the specialist for assemblies that are mostly copper or brass. For packaging, VpCI-126 Blue film and VpCI-146 paper are rated on all metals. Avoid VpCI-609, BioCorr and VpCI-419 on anything containing copper or brass.
Can I use VpCI-422 on aluminum parts?
No. Cortec lists VpCI-422 and VpCI-423 as N/A on aluminum alloys. Use VpCI-426 (rated on all eight metals and singled out for aluminum), VpCI-429 (pH neutral) or VpCI-427 (aluminum-only cleaner) instead.
How long will a water-based rust preventative protect indoors?
It depends on concentration. Cortec’s application guides for VpCI-377 and VpCI-316 give up to one year at 2 to 5 percent, up to two years at 5 to 10 percent, and possibly more than two years at 10 to 20 percent. BioCorr is ready to use and is rated for up to two years plus indoors. In every case the parts should be clean and dry before application and stored out of direct weather.
Is any Cortec packaging film rated for outdoor storage?
One: MilCorr VpCI shrink film, a 10 mil UV-stabilized composite rated 4, outside. VpCI-126 Blue, EcoWeave, the papers and the Cor-Pak products are all rated 2, inside, and should be used under a roof or inside a container.
Do VpCI emitters work in an open crate or on a shelf?
Not usefully. Emitters, foams, tablets and pouches are rated 1, enclosed, because they work by saturating the air inside a sealed space. Cortec describes an open package as giving minimal or no protection. Close the box, seal the bag, or use a contact product such as a liquid RP or paper instead.
Can VpCI products remove rust that is already on a part?
No. Vapor phase inhibitors stop corrosion from starting or continuing; they do not reverse it. Use a rust remover first (VpCI-422 or 423 on ferrous, VpCI-426 or 429 on mixed metals), rinse, dip in a VpCI cleaner to stop flash rust, then apply the preservative or packaging you have chosen from the tables above.
If your situation does not fit neatly into one row, send us the metals, the exposure and the storage time and we will point you at the right product and concentration. Contact Solvent Recycling Systems.
Data source: compiled from Cortec application guides and technical literature (2013 to 2017 editions); confirm against the current product data sheet before specifying.