Water-Based Biodegradable Rust Preventative – 5 Gallon Pail (Cortec® BioCorr®)

Description

BioCorr® is a water-based, biobased, biodegradable rust preventative that leaves a dry film on the metal that is virtually undetectable. It is ready to use — apply by dipping or spraying, no dilution — and the 5-gallon pail suits a basket dip tank, a spray pot or topping up a working bath. It is a USDA Certified Biobased Product with 64% biobased content, and Cortec positions it as the environmentally sound VpCI® alternative to petroleum-derived rust preventative oils.

BioCorr is the product to specify when a rust-preventative oil is doing the job but the oil itself is the problem: oily parts and floors, a cleaning step before assembly, a disposal bill. Cortec rates it for up to two years of indoor storage, or for the length of a shipment when combined with VpCI packaging such as VpCI-126 film, and describes it as suited to aggressive indoor and mild outdoor environments. In the Cortec Product Consultation Guide it carries a severity rating of 2 (inside storage) on carbon steel, stainless steel, cast iron, aluminum, galvanized steel, copper, brass and solder; the current data sheet, however, shows shorter humidity-cabinet life on copper and aluminum (160 to 200 hours against 600 hours on carbon steel), so use VpCI-316 for copper and brass. The film is dry, so parts do not pick up dirt and in most cases need no cleaning before machining, assembly or painting. It is 64 % biobased, USDA BioPreferred certified and VOC free.

Typical applications

• Biodegradable preservative for machines and equipment
• Temporary coating for storage and shipment
• Pipes, flanges and gears
• Cast iron, sheets and coils
• Final rust-preventative dip or spray after aqueous parts washing
• Machined, stamped and cast parts held between operations or awaiting assembly
• Replacement for rust-preventative oils in dip tanks, spray booths and washer rinse stages

How to apply BioCorr

1. Surface preparation. SSPC-SP-1: free of grease, oil, corrosion, dirt, dust and mill scale. Parts straight out of a washer running a VpCI-41x cleaner (VpCI-414, 416 or 418LM) are ideal.
2. Mixing. Ready to use: do not dilute and do not heat. Mix the container thoroughly before charging the tank, agitate the tank daily (a small pump or rotary mixer prevents settling), and keep it covered; contamination destabilizes the emulsion.
3. Dip application. Charge a clean tank, submerge the part so recesses are wetted, remove and dry before packaging or further processing.
4. Spray application. Any spray equipment works; the viscosity is similar to water. Apply a light coat to every critical surface. A milky white film means over-application, which greatly extends dry time.
5. Drying. 15 to 30 minutes at 70 °F and 50 % relative humidity; drips can be returned to the tank. Forced air or heat shortens dry time, but stay at or below 140 °F (60 °C) and do not overdo the air flow, which strips the film before it forms. Dry completely before packaging.
6. Removal. Often unnecessary. When needed, rinse with water and follow with a VpCI-41x cleaner to prevent flash rust.
7. Storage and shelf life. Up to 24 months in the original sealed container.

Checking concentration

BioCorr is sold ready to use, but a dip tank still drifts as water evaporates and product is carried out on parts. Cortec’s target for a standard BioCorr bath is 4.4 to 4.8 °Brix and pH 8.4 to 9.1. Both fall over time; when they drop below range, add fresh BioCorr, not water. A pH below 8.4 leaves the bath open to biological growth and fouling. For the BioCorr SC concentrate, Concentration (% by volume) = 1.07 × Brix + 0.39 in DI water, giving targets of about 1.5 °Brix at 2 %, 4.3 at 5 % and 9.0 at 10 %. Field water, cleaner carry-over and oil shift refractometer readings, so build a site-specific reference chart from your own water. See the refractometer and pH charts for every Cortec product.

Where it fits in the Cortec line

BioCorr is the ready-to-use, biobased member of Cortec’s water-based rust preventatives. VpCI-377 is the concentrate version, diluted 2 to 20 % to tune protection length against cost; VpCI-379 leaves a dry film that can be painted over; VpCI-316 covers copper and brass. For outdoor or marine exposure step up to the oil-based VpCI-329D or biobased EcoLine 3690. BioCorr is also a natural final-rinse additive for Build-All and Magido aqueous parts washers: clean, protect and dry in one cycle, then pack in VpCI-126 bags. Browse the full Cortec VpCI line.

Field notes

A Frankfort, Indiana OEM parts maker met its two-year requirement with an oil-based rust preventive that had high VOC, dripped and created slip hazards. BioCorr was tested on production lines, used first on hub heat-treat and then replaced the oil on every line: two-year protection, product cost down 30%, safety issues gone. (Cortec Case History #363)

A Midwest OEM stored transmissions 1 to 9 months in an uncontrolled warehouse before export wrapping, and its flash-rust wash additive gave about 30 days, not enough for Midwest corrosion season. After the wash the transmissions are sprayed with BioCorr ATF, transmission-fluid compatible and near-invisible when dry, then wrapped in VpCI-126 for export. (Cortec Case History #625)

A Croatian machinery plant that bans solvent coatings ships steel cylinders to a U.S. customer with green-tinted BioCorr after machining, then a 25 by 25 cm BioPad and a 3 mil VpCI-126 film wrap. A test pallet left outdoors from April 15 to July 26, 2022 showed no corrosion after three months outside despite the system being rated for indoor use. (Cortec Case History #778)

Specifications

Protection	Up to two years of indoor storage; or during shipments when combined with VpCI packaging materials
Humidity (ASTM D1748)	Carbon steel 600 hours; copper 160–200 hours; aluminum 160–200 hours
VOC	VOC free
Appearance	Milky white liquid
pH	8.4–9.1
Density	8.3–8.4 lb/gal
Film	Dry, virtually undetectable
Form	Ready to use; do not dilute or heat; agitate before each use
Surface preparation	SSPC-SP-1
Application	Dip or spray
Dry time	15–30 minutes at 70 °F, 50% RH; forced drying not above 140 °F (60 °C)
Bath control	4.4–4.8 °Brix; pH 8.4–9.1
Tests	ASTM D4627 cast iron chip test: pass; ASTM D1735 water fog; NACE RP0487-2000
Metals	Multi-metal: carbon steel, stainless steel, cast iron, aluminum, galvanized steel; copper and brass are protected for a shorter period (see humidity data) — use VpCI-316 where yellow metals are the priority
Consultation guide rating	2 – inside storage
Removal	Usually not required; water rinse followed by a VpCI-41x cleaner
Storage	Store sealed; keep from freezing
Shelf life	Up to 24 months
USDA Certified Biobased Product	Yes — 64% biobased content (USDA BioPreferred Program)
Size	5 Gallon Pail
Shipping weight	45 lb (20.4 kg)
Availability	In stock
Cortec product number	12002968

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.