What is Interprime 820 Base and why choose it?
Interprime 820 Base is a high performance 2-component epoxy primer from International Náutica, formulated with inert pigments and extenders. It is designed for professional and industrial use on a wide range of substrates both above and below the waterline, providing excellent anticorrosive protection and an easy-to-sand surface for subsequent coatings.
When mixed with the dedicated curing agent YPA824, Interprime 820 forms a durable epoxy film suitable for steel, aluminium, stainless steel components, fiberglass (GRP/gelcoat) and properly prepared wood and epoxy fillers/primers. Its combination of corrosion resistance, wide substrate compatibility and controlled drying/overcoating times makes it a dependable choice for high quality yacht and marine maintenance systems.
Main features
- High performance epoxy system: 2-component epoxy primer with inert pigments and extenders for demanding marine environments.
- Excellent anticorrosive protection: Suitable for use on steel and aluminium on both underwater and topside areas.
- Easy sanding: Formulated to sand easily, helping achieve smooth, fair surfaces ready for undercoats and topcoats.
- Wide substrate suitability: Can be used on steel, aluminium, stainless steel components, fiberglass (GRP/gelcoat), bare wood, lead and compatible epoxy primers and fillers.
- Versatile application methods: Can be applied by airless spray, air atomised (conventional) spray, brush or roller.
- Flexible overcoating window: Long maximum overcoating intervals with a range of epoxy fillers, tiecoats, barrier coats and undercoats.
- Professional grade formulation: For interior and exterior use as part of comprehensive epoxy coating systems.
Technical specifications
- Product type: High performance 2-component epoxy primer
- Base (Part A): INTERPRIME 820 BASE (YPA828 White, YPA829 Grey – EU only)
- Curing agent (Part B): YPA824
- Colour: White (YPA828), Grey (YPA829)
- Finish: Satin
- Specific gravity: 1.54
- Volume solids: 47–49% (depending on source sheet)
- Mix ratio: 3:1 by volume (base : curing agent)
- Typical shelf life: 2 years
- VOC (as supplied): 431–448 g/L (depending on data sheet version)
- Recommended DFT per coat: 125 microns dry
- Recommended WFT per coat: 255–275 microns wet (depending on system guidance)
- Theoretical coverage: 3.64 m²/L per coat
- Practical coverage (by spray): approx. 2.8 m²/L per coat
- Touch dry (approximate):
- 10°C: 12 hours
- 15°C: 9 hours
- 23–25°C: 6 hours
- 35°C: 5 hours
- Pot life (after mixing):
- 10°C: 12 hours
- 15°C: 6 hours
- 23–25°C: 4 hours
- 35°C: 3 hours
- Application temperature ranges:
- Ambient: 10–35°C
- Product: 10–35°C
- Substrate: 10–35°C
- Unit sizes: 5 L and 20 L (base)
- Methods of application: Airless spray, air atomised (conventional) spray, brush, roller
- Thinners: YTA910, YTA920 or YTA061 Epoxy Thinner No. 7 (AP only), as specified
- Recommended wet film thickness direct to metal (guidance): approx. 160 microns WFT when thinned 15% and sprayed
Applications and use cases
Compatible substrates
- Steel: Blast damaged or corroded areas to near white metal (e.g. Sa 2½ / Class 2.5) or grind with 24–36 grit abrasive discs to a 50–75 micron anchor profile.
- Aluminium: Low pressure grit blast using aluminium oxide or copper-free equivalent, or power disc with 24–36 grade discs to a 50–75 micron profile. Power wire brushing is not permitted.
- Stainless steel: Light grit blast to produce a profile of approx. 50 microns before applying a thinned coat of Interprime 820 as a tie coat.
- Lead: Degrease, sand with 120 grade paper or power wire brush, clean thoroughly and pre-prime with an appropriate International primer as specified in the coating system.
- Fiberglass / GRP (gelcoat): Wash with appropriate cleaner, rinse with fresh water and allow to dry. Sand with 180 grade paper, ensuring all waxes and uncured resins are removed; remove sanding debris by vacuuming and clean air blow-down.
- Bare wood: Sand with 80–280 grade paper. Remove oil from oily timbers (e.g. teak) using recommended thinners. The first coat of primer may be thinned 15% with suitable thinner. Everdure (AP only) may be used to seal timbers if required.
- Existing epoxy primers: Sweep blast or abrade with 120–180 grade paper.
- Epoxy fillers: Sand with 60–120 grade paper. Do not wipe epoxy fillers with solvent.
Typical overcoating systems
Within the specified minimum and maximum overcoating intervals (which depend on temperature), Interprime 820 can be overcoated with selected epoxy and polyurethane products, including:
- Epiglass HT9000
- Epoxy Tiecoat
- Interfill 830, Interfill 833
- Interprime 820 (itself)
- Interprime 880
- Interprotect and Interprotect (Professional)
- Microsurfacer
- Perfection Pro Undercoat
- Quick Build Sealer and Quick Build Surfacer
- YRA600 Undercoat
Marine and industrial use cases
- Yacht hulls and underwater areas: As an anticorrosive epoxy primer on steel and aluminium hulls above and below the waterline, prior to tiecoats, barrier coats and antifouling systems.
- Superstructures and topsides: As a high build, easy-sanding epoxy base for fillers, surfacers and polyurethane undercoats.
- Stainless steel fittings: For trim tabs, stern drive gear and other stainless steel components, used with a light blast and thinned tie coat.
- Repairs and refurbishment: Over compatible epoxy fillers and primers where strong adhesion and recoat flexibility are required.
- Wooden structures: As part of an epoxy priming system on suitably prepared and, if required, sealed timber.
FAQ – Interprime 820 Base
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Is Interprime 820 Base suitable for underwater areas?
Yes. The product is described as suitable for use on a variety of substrates above and below water when used as part of an appropriate coating system.
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Which substrates can I apply Interprime 820 Base to?
It can be applied to suitably prepared steel, aluminium, stainless steel, lead, fiberglass/GRP (gelcoat), bare wood, compatible epoxy primers and epoxy fillers.
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What is the correct mixing ratio?
The base (Interprime 820) must be mixed with curing agent YPA824 at a ratio of 3:1 by volume.
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Can I apply it by brush and roller?
Yes. It can be applied by airless spray, air atomised spray, brush or roller. Brush is typically recommended for touch-ups; spray methods are used for larger areas and higher build.
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What thinners should be used?
Depending on region and application method, YTA910, YTA920 or YTA061 Epoxy Thinner No. 7 (AP only) are specified. The choice depends on application temperature and spray method.
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At what temperatures can I apply Interprime 820?
The ambient, product and substrate temperatures should all be between 10°C and 35°C during application.
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How thick should each coat be?
The recommended dry film thickness is 125 microns per coat, corresponding to approximately 255–275 microns wet film thickness, depending on system guidance.
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How long can I wait before overcoating?
Minimum and maximum overcoating intervals depend on temperature and the next product. As an example, at 25°C typical minimum overcoating times range from 8–24 hours and maximum times are generally up to 3–6 months for many compatible epoxies. Consultar ficha técnica del fabricante.
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Can I thin the product more than recommended to improve flow?
No. The documentation warns not to excessively thin when applying high-build coats, as this can affect film build and performance.
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Is Interprime 820 for professional use only?
Yes. The safety data sheet specifies that it is for professional use only.
Section 14 – Transport information
According to the safety data for Interprime 820 White Part A, transport information relevant to Interprime 820 Base includes:
- UN number / ID number: UN1263
- UN proper shipping name: PAINT
- Transport hazard class: Class 3 (flammable liquid)
- Packing group: II
- Environmental hazards: Not classified as marine pollutant under ADR/RID, IMDG or IATA in the provided data.
- ADR/RID special provisions: 640 (C), Tunnel restriction code (D/E)
- IMDG emergency schedules: F-E, S-E
- Special precautions for users: During on-site transport, always move the product in closed, upright and secure containers, and ensure that personnel know the actions to take in case of accident or spillage.
- Bulk transport according to IMO instruments: Not applicable.
Section 8 – Individual protection measures
The safety data sheet for Interprime 820 White Part A (base) provides the following guidance on personal protective equipment (PPE) and exposure controls:
- General hygiene measures: Wash hands, forearms and face thoroughly after handling and before eating, drinking, smoking or using the lavatory. Contaminated work clothing should not leave the workplace and must be washed before reuse.
- Eye/face protection: Use chemical splash goggles or equivalent safety eyewear complying with an approved standard whenever there is a risk of liquid splashes, mists, gases or dusts.
- Hand protection:
- Wear chemical-resistant, impervious gloves complying with relevant standards whenever handling the product.
- For prolonged or frequently repeated contact, gloves with protection class 6 (breakthrough time > 480 minutes according to EN374) are recommended. Recommended materials: Viton or Nitrile, thickness ≥ 0.38 mm.
- For brief contact, gloves with protection class ≥ 2 (breakthrough time > 30 minutes according to EN374) are recommended. Recommended material: Nitrile, thickness ≥ 0.12 mm.
- Gloves must be replaced regularly and whenever there are signs of damage or deterioration.
- Body protection: Select protective clothing based on the specific task and associated risks. Where there is a risk of ignition from static electricity, use antistatic protective clothing (e.g. antistatic overalls, boots and gloves) in accordance with EN 1149.
- Other skin protection: Use appropriate protective footwear and any additional skin protection measures as required by the work being performed.
- Respiratory protection:
- Where ventilation is inadequate or exposure limits may be exceeded, wear a respirator conforming to EN140 with type A/P2 filter or better.
- During dry sanding, flame cutting and/or welding of the dry paint film, wet sanding/flatting should be used where possible. If exposure cannot be controlled by local exhaust ventilation, suitable respiratory protection must be worn.
- Engineering controls: Use only with adequate ventilation. Process enclosures, local exhaust ventilation or other engineering controls must keep airborne concentrations below recommended or statutory limits and below the lower explosion limit. Use explosion-proof ventilation equipment.
- Environmental exposure controls: Emissions from ventilation or process equipment should be checked to ensure compliance with environmental regulations; fume scrubbers, filters or process modifications may be required to reduce emissions.
*Contenido generado por IA
