Water-Based 2K DTM Epoxy Primer — Part A – Clear – 3.5 Gallon (Cortec® VpCI®-395 Part A)

Description

VpCI®-395 Part A is the resin component of Cortec’s two-component water-based epoxy primer. Applied direct to metal, rated for immersion service, 1,000 hours salt spray at 0.2 lbs/gal VOC. This is the clear grade in a 3.5-gallon container; order one gallon of Part B to complete the 3.5:1 clear-base kit (the white base mixes 4:1). Supplied made to order, approximately 15-day lead time, minimum order four.

VpCI-395 is the primer Cortec specifies where the steel will be wet: ballast and storage tanks, sumps, splash zones, structures that see standing water. It is one of only two coatings in the Cortec Product Consultation Guide rated 5 (immersion service in corrosive liquids such as salt water or crude oil) on carbon steel, stainless steel, cast iron, aluminum and galvanized steel; it is not rated for copper, brass or solder. Because it is water-based, cleanup is water and VOC is 0.2 lb/gal, against more than 3 lb/gal for a conventional solvent-borne epoxy. On aluminum, galvanized or plated substrates apply VpCI-373 wash primer first. Indoors, out of UV, it can serve as its own topcoat; outdoors it should be topcoated with VpCI-386 or another Cortec finish. Cortec’s brochure notes VpCI-395 is sold in kits, which is why Part A comes short-filled to take the Part B.

Typical applications

• Direct-to-metal primer on structural steel
• Immersion service conditions
• Harsh outdoor unsheltered environments
• Ballast, storage and holding tank interiors
• Pump bases, sumps and splash-zone steel
• Water and wastewater plant equipment
• Interior topcoat where UV exposure is not a factor
• Primer under VpCI-386 on outdoor structures

How to apply VpCI-395

1. Surface preparation. The substrate must be free of grease, oil, dirt, fingerprints, drawing compounds, rust inhibitors and anything else that would affect adhesion. Cortec recommends VpCI-440 or a similar phosphatizing pretreatment on production lines and a minimum of NACE No. 3 / SSPC-SP6 commercial blast on structural steel. On aluminum, galvanized or plated substrates apply VpCI-373 at 0.5 to 1.0 mil first and test adhesion before full-scale work.
2. Mixing. Mix 4 parts Part A with 1 part Part B by volume and power-agitate to a uniform consistency with a squirrel-cage or drill mixer. When spraying from a pressure pot allow 15 to 30 minutes of sweat-in time before application. Pot life is 2 to 3 hours; mix only what you will use.
3. Dilution. The mixed material may be thinned with water up to 10 % by volume to adjust viscosity.
4. Conditions. Apply between 45 and 90 °F (7 to 32 °C) with the surface at least 5 °F (2 °C) above the dew point. Water-based epoxies want a clean surface and dry air.
5. Equipment. Spray, roll, brush or dip. HVLP or conventional spray: 0.009 to 0.021 in tip, 45 to 55 psi air and 10 psi fluid, 3/8 in ID fluid hose no longer than 50 ft, dual-regulated pot kept at gun height. Airless or air-assisted airless: 0.015 to 0.035 in tip, 1,800 to 2,500 psi, 3/8 in ID hose (a 1/4 in whip end is fine) no longer than 100 ft. Tip size depends on pressure and viscosity. Cortec’s brochure lists spray, brush and roll.
6. Film build. Apply 1.5 to 3.0 mils (37.5 to 75 µm) dry, 3.0 to 6.0 mils wet. Theoretical coverage is 779 sq ft per gallon of mixed material at 1.0 mil DFT, so plan on roughly 260 to 520 sq ft per gallon at the recommended film.
7. Drying and topcoating. Dry to touch in 20 to 30 minutes and dry to handle in 1 to 2 hours; recoat or topcoat from dry-to-touch up to 72 hours, sanding after that. Force-dry 15 to 20 minutes at 150 °F (65 °C) if needed. Full cure takes 3 to 7 days; allow full cure before immersion.
8. Cleanup. Clean tools with water while wet; once dry use butyl cellosolve or MEK, following the solvent manufacturer’s safety directions.
9. Storage. Keep both components sealed, do not let them freeze and do not store above 100 °F (38 °C). Shelf life is 1 year.
10. See the Cortec coatings application guides and comparison table for the shared spray, prep and storage instructions across the Cortec coating range.

Where it fits in the Cortec line

Part A is sold in aluminum, clear and white; every kit needs one Part B. The other immersion-rated Cortec coating is VpCI-396, a single-component moisture-cure urethane that tolerates marginally prepared steel and works as primer and topcoat in one but is solvent-borne at 3.1 lb/gal VOC. For atmospheric service the water-based acrylics VpCI-386 and VpCI-375 are simpler one-component choices, and VpCI-371 covers hot surfaces. For rusted steel, derust with VpCI-422 or convert the rust with CorrVerter before priming; where blasting is possible, an abrasive blast room gets you to SSPC-SP6 fastest. Browse the full Cortec VpCI line.

Field notes

A Serbian utility’s steel power-line piers in the mountains could not be blasted or water-jetted. Loose rust was wire-brushed, CorrVerter applied at 70 to 80 µm dry film with 10 hours’ drying, then a third-party two-part epoxy mid-coat and polyurethane topcoat at 60 µm each, for a 15-year target life. (Cortec Case History #545)

A state railway in Serbia treated 200 catenary piers at two stations without blasting: wire brush, CorrVerter by brush or roller at 40 to 60 µm dry film with at least 10 hours’ drying, then two coats of VpCI-396 Aluminum at 80 to 100 µm each. The railway adopted the system as its standard. (Cortec Case History #638)

An Illinois refrigeration-coil maker’s solvent-based paint smelled, posed health hazards and under-performed on corrosion. The coils are now lowered into a large circulating dip tank of VpCI-386, covered when idle, for better corrosion performance, lower VOC and a safer shop. (Cortec Case History #616)

Watch: Cortec coatings technology

Video by Cortec Corporation.

Specifications

Salt spray (ASTM B117)	1,000 hours
Humidity (ASTM D1748)	500 hours
VOC	0.2 lbs/gal (24 g/L)
Volume solids	48.60%
Coverage	779 sq.ft/gal @ 1.0 mil DFT
Recommended DFT	1.5–3.0 mils (37.5–75 µm)
Mix ratio	3.5:1 by volume for the clear base (3.5 gal Part A to 1 gal Part B)
Dry to touch	20–30 min
Full cure	3–7 days
Limitation	Usable as a topcoat for interior applications only, not exposed to UV
Type	Water-based two-component epoxy primer, direct to metal; permanent coating
Color	clear
Gloss (ASTM D523)	15–25
Pencil hardness (ASTM D3363)	H; adhesion 5B (ASTM D3359); flexibility ½″ mandrel (ASTM D522)
Recommended WFT	3.0–6.0 mils (75–150 µm)
Viscosity	50–60 s+ Zahn #3
Weight per gallon	11.88 lb (1.42 kg/L)
Flash point	122 °F (50 °C)
Dilution	Water, up to 10% by volume (mixed material)
Sweat-in / pot life	15–30 min sweat-in in a pressure pot; pot life 2–3 hr
Dry to handle	1–2 hr
Recoat	After dry to touch (20–30 min) up to 72 hr; sand thereafter
Force dry	15–20 min at 150 °F (65 °C)
Surface preparation	Clean and contaminant-free; NACE No. 3 / SSPC-SP6 on structural steel; VpCI-373 wash primer on aluminum, galvanized or plated
Application temperature	45–90 °F (7–32 °C), surface 5 °F above dew point
Metals	Carbon steel, stainless steel, cast iron, aluminum, galvanized steel; not rated for copper, brass or solder
Consultation guide rating	5 – immersion service
Storage	Original packaging, indoors, out of direct sunlight, 40–100 °F (4–38 °C); protect from freezing; shelf life 1 year
Minimum order quantity	4
Size	3.5 Gallon
Shipping weight	52 lb (23.6 kg)
Availability	Made to order, approximately 15-day lead time
Cortec product number	12401109

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.