Arcmetal PR 340 High-Build Anti-Corrosive Primer
A zinc phosphate pigmented, high-build one-pack primer applied at 50 to 80 microns dry in one pass, for fabricated steel that will see weather, condensation or intermittent wetting. It carries the anti-corrosive function of the system so that the topcoat can be chosen for colour and gloss.
Grade Arcmetal PR 340 | Range General Metal Finishing | Technology Solvent-borne one-pack primer with zinc phosphate anti-corrosive pigment
Technical Data Sheet
Arcmetal PR 340
Issue 2026.09
1. Product description
A zinc phosphate pigmented, higher build primer applied at 50 to 80 microns dry in one pass, for fabrication that will see weather, condensation or intermittent wetting. It carries the corrosion load of the system so the topcoat can be chosen for colour and gloss, and it is the primer specified under the Arcmetal 2K finishes on exterior work. It dries more slowly than PR 210 and needs the rack space that implies.
2. Features
- Zinc phosphate anti-corrosive pigmentation
- 50 to 80 microns dry in a single pass
- The primer specified under Arcmetal 2K finishes on exterior work
- Full performance over Sa 2 and a half blast cleaning; reduced protective life over St 3
- Force dries in 30 minutes at 70 degrees C after flash-off
3. Recommended uses
Priming fabricated steel for exterior, damp, coastal or wash-down service under Arcmetal 2K 430, 2K 560, AL or WB 270 topcoats. It is the anti-corrosive layer in the two-coat route where a single coat finish would not carry the exposure.
Substrates. Bare mild steel, best performance over blast cleaning to ISO 8501-1 Sa 2 and a half, acceptable over power tool cleaning to St 3 with a stated reduction in protective life; zinc coated steel after degreasing and abrading.
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Solvent-borne one-pack primer with zinc phosphate anti-corrosive pigment | Formulation |
| Appearance | Even primer film; colour as stated on the order | Visual |
| Anti-corrosive pigment | Zinc phosphate | Formulation |
| Volume solids | 45 to 60 per cent | ISO 3233-1 |
| Dry film thickness per coat | 50 to 80 microns | ISO 2808 |
| Through drying, air dry at 30 degrees C | Hard dry overnight, 12 to 24 hours | ISO 9117-1 |
| Adhesion | Cross-cut classification 0 to 1 on correctly prepared substrate | ISO 2409 cross-cut |
| Neutral salt spray to first rusting, primed and topcoated system | 240 to 500 h over power tool cleaned steel (St 3), 500 to 1000 h over blast cleaned steel (Sa 2 and a half) at full two-component build; a ranking test, not a service life prediction | ISO 9227, degree of rusting rated to ISO 4628-3 |
| VOC content, ready for use | 380 to 550 g/l | ISO 11890-1, difference method |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Application method | Airless, air-assisted airless, conventional or HVLP spray. |
| Surface preparation | Degrease, then blast clean to ISO 8501-1 Sa 2 and a half for full performance; power tool cleaning to St 3 is acceptable with a reduced protective life. Zinc coated steel is degreased and abraded. Apply with the substrate at least 3 degrees C above the dew point. |
| Thinning | Thin with the thinner recommended by Arctic for the grade to 20 to 25 s in a 4 mm flow cup at 23 degrees C (ISO 2431) for conventional and HVLP spray. For airless and air-assisted airless, add only the thinner needed for atomisation. |
| Film build | 50 to 80 microns dry per coat. Airless or air-assisted airless spray reaches this in a single pass; with conventional or HVLP spray, build the same film in two or more cross passes, wet on wet. Check wet film with a comb gauge to ISO 2808 during application. |
| Drying schedule | Air dry: hard dry overnight at 30 degrees C. Force dry: flash-off at shop temperature until the film has lost its wet solvent sheen, then 30 minutes at 70 degrees C; at 50 to 80 microns, entering warm air too early traps solvent and causes popping and pinholes. |
| Overcoating | Topcoat within the recoat window stated for the system; outside the window, abrade before topcoating. |
Process. Airless, air-assisted airless, conventional or HVLP spray; substrate at least 3 degrees C above dew point; air dry, hard dry overnight at 30 degrees C, or force dry 30 minutes at 70 degrees C after flash-off. Overcoat within the stated window or abrade before topcoating.
6. Storage and handling
Store in the original containers, tightly closed, in a cool, dry, covered store away from heat and direct sun, and stir thoroughly before use to redisperse any settlement. Shelf life is stated on the label and Certificate of Analysis. Handle and use the product in line with its Safety Data Sheet.
7. Safety and regulatory information
Read the Safety Data Sheet before use. Safety Data Sheets and regulatory declarations are issued by our technical centre against the product and batch supplied, so they are sent on request rather than published. Request a Safety Data Sheet or declaration.
This Technical Data Sheet is published for on-screen reference. The information is given in good faith from laboratory and application experience and describes typical values; it is not a specification and does not replace a trial on your own substrate and line. Arctic Materials may revise this sheet without notice. Issue 2026.09.
Technical Data Sheets on this site are for on-screen viewing. For a controlled copy, write to tech@arcticmaterials.com.
Other grades in this range
Need a Safety Data Sheet, a regulatory declaration or a grade specified to your line? Contact our technical centre.