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MAS Epoxy

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MAS Epoxy

Over 16 years ago, two guys restoring and building boats got together and set out to develop a 'better' epoxy. Since then MAS has developed and now offers a complete line of epoxy products, including epoxy resins, hardeners, fillers, adhesives and a variety of repair kits and specialty products such as wood fillers and fiberglass repair kits. Their hardeners are available in a range of curing speeds and resins offered in low viscosity formulas as well. Some of the unique features of MAS Epoxy include:

  • No blush.
    Nobody likes washing and sanding between coats. As well, washing and sanding between coats has been found to be one of the biggest culprits of contact dermatitis and a large contributor to paint failure. As a result, MAS was developed no-blush.

  • Easy mix ratios.
    MAS Epoxies have a simply 2:1 mix ratio, that you can get close enough to when simply eyeballing the measurement. The simplicity of the ration reduces the screw-up factor, and MAS has made it even easier by featuring one-push pumps.

  • Blendable hardeners.
    The blendable hardeners allow you to customize the speed of cure based on the ambient temperature, this makes MAS Epoxies very convenient to use.

  • Lower viscosity.
    The lower viscosity helps with better saturation of wood fiber and core material without cutting off brushes and have to stab the resin into the fabric or get rid of bubbles.

  • Products

    Epoxy Resin

    • MAS Flag Epoxy Resin - This is the premiere resin for Filleting, Laminating, and Gluing. This resin is highly recommended for general purpose gluing applications where wet-out of fiberglass is not a consideration, as well as for all of your filleting and fairing needs. Its medium body resin was specifically designed to perform as an adhesive and structural laminating foundation, and its medium viscosity allows for the incorporation of fillers when fairing putties, gluing slurries and filleting systems are required. The thicker formula are helps to resist sagging in vertical applications, yet still allows quick wet-outs of light to medium weight fabrics. MAS Epoxy Infusion Resin
    • MAS Infusion Epoxy Resin - Formulated for high performance composite construction, this resin features filament winding, wet pregnation, RTM and pultrusion manufacturing processes which will all benefit from the easy handling, high strength and exceptional toughness of the InfuCure Systems.
    • MAS Low Viscosity Epoxy Resin - This is a superior blend of low molecular weight epoxy resin and reactive dilutents, it offers some great features, including easy wet-out of your material and no blush when you're done. It can be used in a huge variety of applications including boat hulls and structures which need to completely exclude moisture, as well as lamination and bonding of nearly all material. Can be used with MAS fillers such as wood powder or Colloidal Silica to be used as a filling and fairing compound.


    • MAS Slow Epoxy Hardener - Special features of the MAS Slow Hardener include blush free surfaces, good ultraviolet stability, smooth finishes in cured films, excellent osmotic resistance, and the ability to cure under high humidity. The Slow Hardener is intended for use with MAS Epoxy Resin and can be applied in a diverse range of conditions where increased working time is required. It is highly recommend when large surfaces are to be coated or laminated.
    • MAS Medium Epoxy Hardener - Recommended when "overnight" sandibility is more important than continuous laminating and open time (as provided by MAS Slow Hardener) MAS Medium will also provide a beautifully smooth void free finish, with great resistance to milking out during application and fogging in critical clear coating applications.
    • MAS Fast HardenerMAS Fast Epoxy Hardener - Appropriate applications for Fast Hardener include: bonding hardware, spot filling, and fairing. Additionally, the superior bonding strength of Fast formulas is ideal for high strength secondary bonding applications such as structural tabbing and repair of lamination's.
    • MAS Infusion Epoxy Hardener - Formulated for high performance composite construction, this hardener is a 2 component system that features filament winding, wet pregnation, RTM and pultrusion manufacturing processes which will all benefit from the easy handling, high strength and exceptional toughness of the InfuCure Systems.

    Fillers and Fibers

    • MAS Epoxies Milled Fibers - MAS Milled FiberThe Milled Fibers Adhesive Filler is designed for use when epoxy must fill a void and provide extremely high strength and resistance to cracking, applications include bonding and enhance strength fillets.
    • MAS Epoxies Phenolic Micro Balloon Fillers - This filler is designed to be used when low density, lightweight sandable paint ready surfaces are required (organic phenolic hollow spheres). Application uses include fairing and filling.
    • MAS Epoxy Wood Flour - This Wood Flour Fairing Filler is composed of finely ground and filtered wood bark. Designed for use when a hard solid for filling, filleting and bonding is required. Wood Flour resists sagging and running.

    Kits and Specialty Products

    • MAS Handy Epoxy Repair Kits - These epoxy kits come in a handy take-along size, great for quick repairs and bonding. They are small enough to keep on board but have enough epoxy to make most quick repairs.
    • MAS Rapid Cure Epoxy Repair Kits - Great for making quick repairs and bonding, no more than 1/2 oz. of each of the resin and hardener is needed at a time. This product is fast, permanent, and waterproof. The mini sized kits are ideal for leaving on board or at home and useful for quick kayak and canoe, or home repairs.
    • MAS White Gelcote Kit - With this gelcote kit you can permanently repair nicks, gouges and scratches in fiberglass hulls and decks. Can be used immediately over repairs made with polyester and vinylester. When using over repairs with epoxy, the epoxy must first be full cured.
    • MAS Flexbond 5000MAS Flexbond 5000 - This is a high quality, elastic, one component adhesive and joint filler ideal for bonding, caulking, bedding and sealing. Suited for adhesive bonding of different materials in building, interior construction and exterior decoration.
    • MAS Gluzilla Polyurethane Adhesive - This is a one-component, high-bond-strength, moisture-curing adhesive. This adhesive film is 100% waterproof, and it will not dissolve in water, as well it offers excellent resistance to repeated wet/dry cycles.


    What are the differences between Epoxies, Vinylesters and Polyesters?

    These three products represent two resin families. Epoxies can be cured with amine agents as room temperature to form excellent adhesive and composite resins. Vinylesters and Polyesters contain an unsaturated polyester or hybridized vinylester backbone which is catalyzed with a peroxide to condense into cross-linked solid resin.

    Tips and techniques for filler use and selection; filleting and fairing?

    It is no longer necessary to have many different resin systems around for laminating, filling, filleting, fairing and adhesive bonding.MAS Fast Hardener One simple MAS Resin and two hardeners (MAS Slow & MAS Fast), will provide you with all the flexibility required to make different thickened putties for standard build and repair operations.

    Can I apped up the mix by adding more Hardener?

    Absolutely not! Adding more hardener throws off the ratio and you will end up with a gooey mess that never cures.

    How much mixing is required?

    Mixing is the key to a thorough cure, good films and strong bonds. One and a half to two minutes of aggressive mixing, swiping the sides and bottom is recommended. Be sure the mix ratio is two parts resin to one part hardener. Use clean plastic or un-coated paper cups or buckets and a clean mix stick.

    What is blush, and how do I remove it?

    Blush may form over the fast mix hardener and resin. The slow mix generally will not blush. Blush is noticeable as a slippery film formed over the cured surfaces. It can be removed with warm water and a sponge (rinse and wipe).

    What is the re-coat time?

    Since the epoxies developed by MAS are 100% solid (created with no solvents), re-coat time can be as short as it takes to achieve surface tack. If more than 12 hours passes between coats, do a light scuff sand. Use a cotton ball to test if a light scuff is needed, if the epoxy holds the hair of the cotton ball you can re-coat without sanding. However, if it doesn't hold the hair a light scuff sand will help adhesion between coats. Always check for blush on surfaces and remove if present before re-coat. Remember the "Rule of Thumb" test and that warmer conditions make for a faster set.

    What is the "Rule of Thumb" test?

    The "Rule of Thumb" test is if you can press your thumbprint in the epoxy, but there's no tack, then it's ready for a re-coat.

    What are the temperature requirements?

    For a clear coating it is ideal to see the resin remain in temperatures over 55° to 60°F. For bonding, anything over 45°F is adequate.

    How should I clean up after use?

    Latex gloves and other personal protection should always be used when working with epoxies. If you should get any epoxy on your skin, it should immediately be cleaned off with a waterless soap, then followed by a thorough washing with soap and water. Tools can be washed with white vinegar or isopropyl alcohol. Semi-gelled epoxy can be removed with acetone.

    What tools are used to apply the epoxy?

    For coating and fiberglass, a short nap 1/8" nylon bristle roller, plastic squeegee, or 4" disposable brushes should be used. For bonding, a glue brush or a squeegee with notches cut into the edge is ideal.

    How should I protect the epoxy?

    Epoxy surfaces should be protected from sun exposure, clear coats may be protected by a good quality varnish or urethane with UVA protection additives. Paint is always considered a 100% filter. Indoor pieces do not need varnish over epoxy.

    Can a stain be used on the project?

    To use a stain on an epoxy project, use a waterbased urethane stain under the epoxy clear coat. Be sure the stain is fully dry before coating work with epoxy. Always test first.

    What is the shelf life of these products?

    The resin has an infinite shelf life, and the slow and fast catalysts have a shelf life of 1 year in a closed container.

    What surface preparation is needed prior to application of epoxy?

    All surfaces should be cleaned of any contaminates, such as oil, grease and pooled water prior to application. A light sanding is also recommended. A clean cloth moistened with isopropyl alcohol or plain water may be used to clean surfaces and to remove dust. DO NOT USE ACETONE or a TACK CLOTH to clean the surface.

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