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Altex Epoxy Barrier Undercoat - 4 litre

Altex Yacht & Boat Paint Epoxy Barrier Undercoat is a high performance, sandable epoxy high build coating which is both very corrosion and water resistant.
Altex Epoxy Barrier Undercoat - 4 litreclick for larger image
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Smart VIP Card PriceNZ $199.00Save 29%Without Card NZ $279.99Product #8029049
Clearance priced items are subject to availability & stock on hand only. Please check stock with the Smart Crew or you will be advised if not available.
Item excluded from freight specials.

Altex Yacht & Boat Paint Epoxy Barrier Undercoat is a high performance, sandable epoxy high build coating which is both very corrosion and water resistant.

Epoxy Barrier Undercoat is recommended for:

  • Topside & Superstructure final sealing to provide an optimum surface for finish coating
  • As a high build surfacer to remove defects and achieve a finish suitable for application of Altex Polyurethane Undercoat or one of the Elite Polyurethane finish coats
  • As a high build barrier coat for below waterline application, used as part of an Altex Antifouling system
  • Direct application to sanded GRP, epoxy laminated wood and epoxy sealed wood
  • Direct application to epoxy faired surfaces
  • Application over Altex Epoxy Primer or Altex High Build Surfacer
  • Priming / undercoating over degreased & sanded aged polyurethanes, epoxies, fairing systems, gelcoats, epoxy laminates & fibreglass



  • Excellent build properties up to 150µm DFT in a two pass application
  • Excellent surfacing and sanding properties
  • Very good corrosion protection
  • Wide maximum self re-coat times for easy project management
  • Very good water and chemical resistance
  • Epoxy Barrier Undercoat may be top-coated with both acrylic or polyester urethane finishes and is especially formulated as an undercoat or sealer under the Altex Elite® range of polyurethane finish coats
  • May be used as a high build surfacer / undercoat for topcoating with Altex Polyurethane Undercoat
  • May be used in immersion service as part of an Altex Yacht & Boat recommended system


  • Colour: Off-White
  • Mix Ratio: 4 to 1 by volume
  • Thinner: Spray: Altex Thinning Solvent #12
  • Brush/Roller: Altex Thinning Solvent #22
  • Pot Life: 8 hours at 25°C
  • Induction Time: 15 minutes.  
  • Theoretical Coverage Rate: 4.5 sq meters per litre at 100 microns dry
  • Recommended Film Thickness Per Coat: 225-335 microns wet to obtain 100-150* microns dry (*applied in two passes)
  • Application: Air or airless spray, brush or roller
  • Dry Times (25°C / 100 µm DFT / 50% RH): Touch Dry: 90 mins. Dry to Sand: 6 hours

Recommended Recoat:

  • Min. Self Recoat: 30 – 60 mins between passes. 6 hours between coats
  • Max. Self Recoat: 5 days without sanding.
  • Min. To Overcoat: 6 hours for Altex Polyurethane Undercoat
  • Max. To Overcoat: 14 days with thorough sanding for Altex Polyurethane Undercoat Max. To Topcoat (see cure notes below).
  • Undercover with Elite® Polyurethane Finish: 12 Days max - freshly sanded within 3 days of topcoating.
  • Outside with Elite® Polyurethane Finish: 10 Days max - freshly sanded within 3 days of topcoating.

CURE TIME NOTES: Maximum cure times before topcoating are based on thorough fine sanding & dedusting within 3 days and solvent wiping of the surface immediately before application of any subsequent coats. (Dry to sand times will increase with higher film builds, and/or lower temperatures. Cure may be advanced by lightly sanding the partially cured surface with 120 grit to open the film up & allow solvents to escape.)

For more information, Product Data Sheets and MSDS. Please see

Shipping: Smart Marine uses Courier Post and Toll to deliver our NZ orders. All parcels are insured plus you will receive online trace details for peace of mind. Due to insurance and guarantee of delivery, all our parcels will need to be signed for or the courier will leave a card to collect/arrange another delivery time so please consider supplying a business address instead or another where the parcel can be signed for. Orders are processed on week days and are usually collected the next business morning by the courier, if not earlier. North Island delivery is usually 1-3 days, South Island 2-5 and the parcel size can effect this. We also ship to rural addresses and to P.O. boxes but very large/fragile/DG parcels will need a physical address.

Collect Your Order at any Smart Marine Store: Smart Marine happily allows collection of your order (pre-pay online or pay in store), 8am-6pm, 7 days a week via your favourite Smart Marine store: Westhaven, Mt Wellington, Manukau or Hamilton. Simply 'Add to Cart' as normal and select the store you want to collect from via the drop-down options at check-out. The Smart Web Crew will be in touch with when it is ready for you. Easy-peasy! Please let us know when you hope to collect so we can do our best to have it ready for you in good time. You will be required to present your own photo i.d. for pre-paid orders so please bring this with you.

Please click here to view full shipping terms and International Shipping details of required.

**Please Note: ships overseas web orders outside of New Zealand to these countries only: Cook Islands, Fiji, French Polynesia, New Caledonia, Niue, Samoa, Tahiti, Tonga, Vanuatu, Wallis & Fortuna.

Satisfaction Assured! Money Back Gaurantee!

We believe you will be very satisfied with your purchase from Smart Marine.

You are however welcome to return the item if required for exchange or refund excluding shipping costs within 10 days and in its original condition and packaging if you no longer require the item.

On the rare occasion that a product is found to be faulty under warranty or not as described, please contact the Smart Crew and we will promptly remedy the issue for you. If you have any queries regarding items on the SmartWeb or concerns with your purchase, please feel free to contact the Smart Crew for help.

Smart Marine aims to abide and exceed the requirements set by the New Zealand Fair Trading and Consumer Guarantees Act to ensure you have a Smart Shopping Experience!