Arcstruct CM 380 Applied FRP Finish Coat
Two-pack polyurethane finish applied to cured composite mouldings where the part is released without a gel coat, where the gel coat has been repaired or faired, or where colour and gloss have to match adjacent metalwork. It tolerates the flexing of a thin laminate without cracking, resists ultraviolet on outdoor parts, and contains no styrene, so it can be applied outside the lay-up area.
Grade Arcstruct CM 380 | Range Industrial and Infrastructure Coatings | Technology Two-pack polyurethane, styrene-free, solvent-borne
Technical Data Sheet
Arcstruct CM 380
Issue 2026.09
1. Product description
Two-pack polyurethane finish applied to cured composite mouldings, used where the part comes out of the mould without a gel coat, where the gel coat has been repaired or faired, or where colour and gloss have to match adjacent metal work. Formulated to tolerate the flexibility of a thin laminate without cracking and to resist ultraviolet on outdoor parts. A styrene-free route to surface finish, so it can be applied outside the lay-up area.
2. Features
- Styrene-free, applied outside the lay-up area
- Tolerates flexing of thin laminates without cracking
- Ultraviolet resistance on outdoor parts
- Colour and gloss matched to adjacent metalwork
- Force curable within the heat distortion limit of the laminate
3. Recommended uses
Finishing composite mouldings released without a gel coat, gel coated parts after repair or fairing, and composite parts that must match adjacent painted metalwork in colour and gloss.
Substrates. Cured polyester, vinyl ester and epoxy laminates, faired and filled composite surfaces, gel coated parts after abrasion
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Two-pack polyurethane, styrene-free, solvent-borne | Formulation |
| Gloss | Gloss above 70, semi-gloss 35 to 70 or matt below 35 at 60 degrees, by agreement | ISO 2813 |
| Colour | To the agreed colour reference, including matches to adjacent metalwork | Visual |
| Carrier | Organic solvent blend, free of styrene | Formulation |
| Volume solids | 50 to 65 per cent | ISO 3233-1 |
| Density, mixed | 1.1 to 1.4 g/cm3 | ISO 2811-1 |
| Dry film thickness per coat | 50 to 80 micrometres | ISO 2808 |
| Adhesion, cross-cut on abraded laminate | Classification 0 to 1 | ISO 2409 |
| Pencil hardness, cured film | H to 2H | ASTM D3363 |
| Accelerated weathering | 1000 to 2000 hours fluorescent UV with condensation cycling, with gloss retention and colour change reported | ISO 16474-3 or ASTM G154 |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Surface preparation | Cured laminate abraded and degreased with release agent residues removed; gel coated parts abraded and cleaned. |
| Primer or filler | Matched primer or filler coat applied, faired and sanded before the finish coat. |
| Application method | Conventional or HVLP spray. |
| Mixing | Base and hardener mixed at the stated ratio and used within the pot life, with containers resealed and lines kept dry. |
| Film thickness | 50 to 80 micrometres dry per coat. |
| Conditions and cure | Substrate at least 3 degrees Celsius above the dew point during application and initial cure. Ambient cure, or force cure at 40 to 60 degrees Celsius held below the heat distortion temperature of the laminate. |
Process. Conventional or HVLP spray over an abraded and degreased surface with a matched primer or filler coat. Two-pack ambient cure, force curable at moderate temperature within the heat distortion limit of the laminate
6. Storage and handling
Store in the original closed containers under cover, dry and out of direct sun, at 5 to 35 degrees Celsius, and reseal the hardener immediately after use because it reacts with atmospheric 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
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