Biobased Rust Remover Gel for Vertical Surfaces – 5 Gallon Pail (Cortec® VpCI®-423)

Description

VpCI®-423 is the gel grade of Cortec’s organic rust remover: a thixotropic, 91 % USDA-certified biobased formulation that clings to vertical and overhead surfaces where a liquid just runs off. It is NSF A3 registered, uses natural organics to remove rust, scale and oxides, and will not damage most paints, plastics, wood, textiles, ceramics or rubber. The 5-gallon pail is used as supplied, by brush or roller.

VpCI-423 is for the rust you cannot bring to a dip tank: a press frame, the inside wall of a tank, the flank of a large gear, a rusted weldment on a machine base, a structural member, the underside of a platform. The gel stays where it is brushed, keeps the surface wet long enough to do its work, and lifts rust without aggressive attack on the base metal because it carries VpCI inhibitors that also prevent flash corrosion while it works. It is completely organic, readily biodegradable and non-flammable, and it is far safer to handle than an acid gel. In the Cortec Product Consultation Guide VpCI-423 is approved for carbon steel, stainless steel, cast iron, galvanized steel, copper, brass and solder; it is not rated for aluminum, where a VpCI-426 product is the correct choice. As with any derusting step, the freshly exposed steel should be neutralized with a VpCI cleaner and protected before it is stored.

Typical applications

• In-process rust removal for parts and metal stock
• Rust removal in hard-to-reach, vertical and overhead locations
• Automotive and marine restoration
• Manufacturing equipment maintenance
• Large gears, shafts and machined components too big for a dip tank
• Press frames, machine bases, tanks and structural steel in place
• Spare-parts preservation programs (derust, neutralize, protect, package)
• Rust stains on concrete walls and floors

How to apply VpCI-423

1. Pre-clean. Remove grease, debris and loose flaky rust with a rag, wire brush or pressure wash.
2. Apply the gel. Brush or roll VpCI-423 as supplied over the rusted area in a generous coat. Typical coverage is 200 to 600 sq ft per gallon (5 to 15 m² per liter) depending on rust depth.
3. Keep it wet. Do not let the gel dry. On long dwell times wrap the part or area in clear plastic stretch film to hold the gel wet; on heavy rust agitate the gel with a brush and re-apply as the rust releases. Light rust releases in about 15 minutes, medium in about 30 minutes, heavy rust in an hour or more.
4. Rinse. Rinse with water to remove dissolved rust and residual gel. On concrete, rinse and neutralize with MCI-2060.
5. Neutralize and protect. Wash with a 10 % solution of VpCI-414 or VpCI-416 (or spray 5 to 10 % VpCI-418 LM), rinse, and blow off or air dry on a clean surface. The dry inhibitor film prevents flash rust; for storage follow with a VpCI coating, rust preventative or VpCI packaging.
6. Storage. Keep the pail closed. Non-flammable; store at room temperature and keep from freezing.

Compatibility

Cortec’s elastomer testing rates VpCI-423 fully compatible at 100 % concentration with neoprene, nylon, PET, acetal and fiberglass; nitrile was not reported for the gel, and it is rated not compatible with the liquid VpCI-422, so use neoprene or Viton gloves and test brushes and containers. The gel will not damage most paints, plastics, wood, textiles, ceramics or rubber, but test any finish you want to keep. See the full oil and elastomer compatibility charts.

Where it fits in the Cortec line

VpCI-423 is the vertical-surface member of Cortec’s organic rust removers. VpCI-422 is the same chemistry as a liquid for dip tanks and spray; VpCI-426 is the heavier rust and scale remover that is also rated for aluminum; VpCI-429 is the pH-neutral chelating remover that needs no neutralizing step. Neutralize with VpCI-416 for the longest post-clean protection or VpCI-414 for the strongest cleaning, and note that parts that do fit a tank are usually faster through the immersion and spray stages of Build-All and Magido aqueous parts washers. For structures that cannot be derusted at all, CorrVerter rust converter primer is the alternative. For spot work, EcoClean 423 puts the same gel in a 16 oz bottle. See the full rust prevention range for what comes after.

Field notes

Severe rust on the machined mounting pads of gas-turbine base plates would have prevented seating and caused vibration. VpCI-423 gel was left to dwell and cleaned off with 10% VpCI-414, about one hour per plate with 15 to 20 minutes hands-on, removing all corrosion in far fewer man-hours than grinding. (Cortec Case History #681)

A Houston air-cooler manufacturer found its nitrogen-purged bundles leaked as the steel blinds contracted in temperature swings. It switched to fogging VpCI-337 into the bundles and sealing with PVC bumper gaskets, with flange faces de-rusted with VpCI-423 gel, degreased with VpCI-414 and sprayed with CorShield VpCI-368. No hermetic seal is needed. (Cortec Case History #823)

A St. Paul, Minnesota plastics molder had machine cooling chambers nearly closed off by rust. The chambers were cleared by circulating an 8% descaler for about three hours, corroded parts dipped in VpCI-422 and VpCI-423 for eight hours and rinsed, then sprayed with EcoSpray VpCI-389 for a waxy protective film that also eased reinsertion. (Cortec Case History #050)

Specifications

pH	2.3 neat
Registration	NSF A3 registered for indirect food contact
Density	9.6–10.0 lb/gal (1.16–1.19 kg/L)
Form	Dark brown gel that clings to vertical and overhead surfaces
Compatibility	Will not damage most paints, plastics, wood, textiles, ceramics or rubber
Performance	Prevents flash corrosion
Application	Brush or roll as supplied; keep wet, wrap in plastic film on long dwell times
Dwell	Let stand 10–15 minutes, then rinse; heavy rust may need more than one treatment
Coverage	200–600 sq ft/gal (5–15 m²/L)
Neutralize	Rinse, then 10 % VpCI-414 or VpCI-416 wash, or 5–10 % VpCI-418 LM spray
Chemistry	Organic, readily biodegradable, non-flammable
Metals	Steel, iron, brass, copper
Not recommended	Aluminum (use VpCI-426)
Elastomers	Compatible with neoprene, nylon, PET, acetal, fiberglass
Shelf life	2 years
Storage	Original packaging, indoors, out of direct sunlight, 40–100 °F (4–38 °C)
USDA Certified Biobased Product	Yes — 91% biobased content (USDA BioPreferred Program)
NSN	6850-01-482-4536
Size	5 Gallon Pail
Shipping weight	52 lb (23.6 kg)
Availability	In stock
Cortec product number	11600105

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.