Arcshield MR 420 Deck, Boot Top and Topside Finish
A finish range for above-water areas, supplied as an acrylic polyurethane or polysiloxane topside and superstructure finish, or as an abrasion-resistant deck grade that accepts anti-slip aggregate. The boot top is coated with the abrasion-resistant grade over the anti-corrosive scheme.
Grade Arcshield MR 420 | Range Protective and Marine Coatings | Technology Acrylic polyurethane or polysiloxane finish, with an abrasion-resistant deck grade
Technical Data Sheet
Arcshield MR 420
Issue 2026.09
1. Product description
A finish range for the above-water areas, supplied either as an acrylic polyurethane or a polysiloxane topside and superstructure finish with gloss and colour retention, or as an abrasion-resistant deck grade that accepts anti-slip aggregate for working decks, gangways and cargo areas. The boot top sits between these duties and takes alternating immersion, wash and impact from berthing and ice, so it is coated with the abrasion-resistant grade over the anti-corrosive scheme. Antifouling is a separate, biocidal product category whose supply depends on registration of the actives at the point of sale, and it is not covered by this grade.
2. Features
- Acrylic polyurethane or polysiloxane grades for gloss and colour retention on topsides and superstructure
- Abrasion-resistant deck grade that accepts anti-slip aggregate
- Abrasion-resistant grade also used at the boot top for alternating immersion, wash and berthing or ice impact
- Applied over Arcshield EP or MR anti-corrosive coats
3. Recommended uses
Topsides, superstructure, working decks, gangways, cargo areas and boot tops. Antifouling is a separate biocidal product category and is not covered by this grade.
Substrates. Over Arcshield EP or MR anti-corrosive coats on carbon steel, over aluminium superstructure with the appropriate etch or epoxy primer, and over sound aged polyurethane finishes after preparation and adhesion testing.
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Acrylic polyurethane or polysiloxane finish, with an abrasion-resistant deck grade | Formulation |
| Finish | Gloss or semi-gloss for topside grades; deck grade plain or with broadcast anti-slip aggregate | Visual, supplier protocol |
| Colour | Shade to the specification | ISO 3668 |
| Specular gloss, topside gloss grades | Typically 70 to 90 units at 60 degrees; semi-gloss and deck grades lower, stated per grade | ISO 2813 |
| Gloss and colour retention | Assessed comparatively after artificial weathering | ISO 16474-3 exposure, gloss to ISO 2813, colour difference to ISO 11664-4 |
| Volume solids | Typically 50 to 65 per cent for acrylic polyurethane and 65 to 80 per cent for polysiloxane | ISO 3233-1 |
| Dry film thickness per coat | Typically 50 to 75 µm for acrylic polyurethane and 75 to 125 µm for polysiloxane; deck grade to the specification | ISO 2808 |
| Abrasion resistance, deck and boot top grades | Typically 60 to 150 mg loss, CS-17 wheel, 1000 cycles, 1 kg load | ISO 7784-2, ASTM D4060 |
| Surface drying | Typically 1 to 4 h at 20 °C, slower at lower temperature | ISO 9117-3 |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Method | Airless or conventional spray for finish quality; roller for decks and for aggregate broadcast work. |
| Substrate | Over Arcshield EP or MR anti-corrosive coats on carbon steel, over aluminium superstructure with the appropriate etch or epoxy primer, and over sound aged polyurethane finishes after preparation and adhesion testing. |
| Thinning | Thinner as stated on the product data for the grade, added only as needed for the application method. |
| Applied film thickness | Typically 50 to 75 µm dry per coat for acrylic polyurethane and 75 to 125 µm for polysiloxane, verified to ISO 2808; deck grade and aggregate to the specification. |
| Application conditions | Substrate temperature at least 3 °C above dew point (ISO 8502-4) and relative humidity normally 85 per cent or less during application and cure. |
| Recoat and colour control | Applied inside the recoat window of the coat beneath. Colour-critical work is applied in a single continuous operation across a visible area to avoid banding. |
Process. Airless or conventional spray for finish quality, roller for decks and for aggregate broadcast work. Application is closed out inside the recoat window of the coat beneath, and colour-critical work is applied in a single continuous operation across a visible area to avoid banding.
6. Storage and handling
Store all components in their original closed containers in a dry, covered store, typically between 5 and 35 °C and out of direct sunlight, and keep containers of curing agent tightly closed against moisture. Shelf life is stated on the label and the 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.