Rust & Scale Remover, Brightens Aluminum and Copper – 5 Gallon Pail (Cortec® VpCI®-426)

Description

VpCI®-426 is a heavy-duty, water-based rust and scale remover concentrate with a different dilution for each metal: steel, copper, aluminum and magnesium each get their own ratio. It removes rust, scale and oxidation from virtually any metal surface, is especially effective on aluminum, carbon steel, stainless steel and copper, and leaves aluminum with a bright finish. The 5-gallon pail makes 5 to 25 gallons of working solution depending on the metal.

VpCI-426 is the rust remover to reach for when the load includes aluminum or magnesium, when scale rather than surface rust is the problem, or when appearance matters: it is the product Cortec trialed to restore stainless steel parts that were being scrapped for cosmetic staining. It is nitrite-free and incorporates VpCI technology to limit attack on the base metal, and in the Cortec Product Consultation Guide VpCI-426 and its gel and powder forms are approved on all eight listed metals: carbon steel, stainless steel, cast iron, aluminum alloys, galvanized steel, copper, brass and solder. It is acidic, so the freshly cleaned metal must be rinsed and neutralized; Cortec specifies VpCI-414 at 1:5 or 1:10 for that step, or VpCI-416 where longer post-clean protection is wanted. Gel and powder grades and pre-measured Safe-T-Charge water-soluble bags are available for vertical work and tank make-up.

Typical applications

• Removing oxide and scale from aluminum parts
• Pre-treatment before anodizing, electroplating or coating
• Rust removal from carbon steel and cast iron
• Brightening aluminum and copper surfaces
• Descaling equipment
• Restoring stained stainless steel components and headers
• Derusting mixed-metal assemblies that VpCI-422 cannot treat

How to apply VpCI-426

1. Set up. A plastic or fiberglass tank of diluted VpCI-426 large enough to submerge the part, a water rinse tank, and a neutralizing tank of VpCI cleaner. Pre-clean grease, debris and loose scale.
2. Dilute for the metal. Sort the load by metal and mix accordingly.

3. Metal	Dilution
   Steel and cast iron	1 part VpCI-426 to 4 parts water
   Copper	Concentrate or 1:1
   Aluminum	1:1 normal; concentrate or 1:1 at elevated temperature for heavy soil
   Magnesium	1 part to 4 parts water
   Powder grade	7 % by weight in water

4. Soak or spray. Immerse the part, or spray and keep the surface wet; do not let it dry on the part. Heat and scrubbing speed removal. Cortec Technical Service puts typical soak time at 15 minutes to 1 hour or more depending on the amount of corrosion; check every 15 to 30 minutes and remove the part when the rust or scale has released.
5. Rinse. Lift, drain back into the tank, and rinse in water so no acid is carried into the cleaner.
6. Neutralize and protect. Dip in VpCI-414 at 1:5 to 1:10 (or 5 to 10 % VpCI-416), set on a clean surface and air dry. The dry inhibitor film prevents flash rust; for storage follow with a VpCI rust preventative, coating or VpCI packaging.
7. On concrete. Apply at 200 to 600 sq ft per gallon (5 to 15 m² per liter), then rinse and neutralize with MCI-2060.
8. Bath life and storage. Filter fines, add fresh product as the bath loads with metal, and cover the tank. Store at room temperature and keep from freezing.

Checking concentration

Concentration (% by volume) = 3.45 × Brix − 0.09 for VpCI-426 in DI water, valid across Cortec’s 0 to 20 % chart (R² 0.99). Target readings are about 0.6 °Brix at 2 %, 1.5 at 5 %, 2.9 at 10 % and 5.8 at 20 %; the 1:4 steel bath reads about 5.8 °Brix, and the 1:1 aluminum bath is above the chart range. Cortec’s pH chart shows working solutions between pH 1.5 and 2.5 over 0 to 20 %, with the data sheet’s 2.5 to 3.5 at 1 % marking the dilute end; pH drift is a useful sign that the bath needs fresh product. Field water and dissolved iron shift readings, so build a site-specific reference chart with your own process water. See the refractometer and pH charts for every Cortec product.

Where it fits in the Cortec line

VpCI-426 is the broadest-metal, heaviest-duty member of Cortec’s rust removers. VpCI-422 is the 92 % biobased organic liquid for steel, copper and brass (not aluminum); VpCI-423 is the same organic chemistry as a gel for vertical surfaces; VpCI-429 is the pH-neutral chelating remover for shops that want no neutralizing step. The neutralizing partner is VpCI-414 at 1:5 to 1:10 or VpCI-416 for up to six months of post-clean protection. The derust, rinse and neutralize stages run well in the immersion and spray tanks of Build-All and Magido aqueous parts washers, and for structures that cannot be derusted, CorrVerter rust converter primer is the alternative. See the full rust prevention range for what comes after.

Field notes

A stainless-steel memorial at a Minnesota taconite mine began corroding within months of dedication. VpCI-426 removed the corrosion and brightened the stainless, VpCI-418 rinsed and neutralized it, and VpCI-386 Clear went on as the topcoat for long-term protection without changing the appearance. (Cortec Case History #081)

An Indiana automotive-electrical plant had parts rusting before they left the building. Its replacement three-stage wash runs 5% VpCI-414 with 0.4% defoamer, a water rinse, then 10% VpCI-377 as the final stage; three months of testing showed no corrosion and the process was approved. (Cortec Case History #095)

Watch: Removing rust with VpCI-426

Video by Cortec Corporation.

Specifications

pH (powder grade)	2.5–3.5 (1% aqueous); Cortec does not publish a pH for the liquid
Dilution — steel	1 part to 4 parts water
Dilution — copper	Concentrate or 1:1
Dilution — aluminum	1:1 normal; concentrate or 1:1 at elevated temperature for heavy soil
Dilution — magnesium	1 part to 4 parts water at room temperature; cleans in about 1–2 minutes
Dilution — powder grade	7% by weight in water
Non-volatile content	20–26% liquid; 95–100% powder
Listings	NSN 6850-01-477-4155
Density (liquid)	8.9–9.1 lb/gal (1.07–1.09 kg/L)
Chemistry	Water-based, nitrite-free
Removes	Rust, scale and oxidation; brightens aluminum and copper
Application	Dip or spray; keep wet; gel grade for vertical surfaces
Soak time	15 min to 1 hr or more, depending on the amount of corrosion (Cortec Technical Service); magnesium about 1–2 min
Neutralize	Rinse, then VpCI-414 at 1:5 or 1:10, or 5–10 % VpCI-416
Coverage (concrete rust stains)	200–600 sq ft/gal (5–15 m²/L); neutralize with MCI-2060
Metals	Carbon steel, stainless steel, cast iron, aluminum alloys, galvanized steel, copper, brass, solder
Consultation guide	Safe to use on all eight listed metals
Concentration check	Vol % = 3.45 × °Brix − 0.09 (DI water); working pH about 1.5–2.5
Other forms	VpCI-426 Gel; VpCI-426 Powder; Safe-T-Charge 5 lb water-soluble bags
Storage	Minimum 32 °F (0 °C), maximum 120 °F (49 °C)
Size	5 Gallon Pail
Shipping weight	48 lb (21.8 kg)
Availability	In stock
Cortec product number	11600608

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.