Product information
AMPRO EPOXY H+K SLOW 4,2 KG
AMPRO™ is a solvent-free epoxy resin system developed for boatbuilding, suitable for bonding wood, surface coating, and fiberglass laminating. It is recommended as a general-purpose epoxy for all types of woodworking, as well as for treating and coating wooden surfaces that will be painted afterwards or where a high-gloss finish is not required. The epoxy is also suitable for high-quality, clear, and transparent finishes that enhance the natural beauty of wood. When thickened with microballoons, AMPRO™ can be used as a fairing compound or profiling filler. In addition to wood, the resin system can also be used to bond composites, metals, and concrete.
As a wood adhesive and surface treatment, AMPRO™ improves the compressive strength of wood fibers and creates a moisture barrier. Compared to untreated wood, surfaces coated with AMPRO™ epoxy stay drier and retain their shape and mechanical properties more effectively. Wooden parts to be bonded or joined can be coated with epoxy before installation. This saves time, simplifies the process, and ensures that the entire surface is properly sealed. Before bonding, the contact surfaces must be roughened. Bonding is done using the AMPRO™ resin system or another Gurit epoxy suitable for wood adhesion.
There are three hardeners available: fast, slow, and extra slow. The extra slow hardener is intended for use only in exceptionally warm conditions. The mixing ratio of resin to hardener is 3:1 by volume and 100:29 by weight. This specified ratio must be followed—any deviation will compromise the quality of the final result and will not affect the curing time. The resin system cannot be thinned with solvents.
- Easy to use
- Less hazardous
- Solvent-free
- Versatile
- Clear
Working Process
The recommended working temperature is 15–25 °C. Cold air and humid conditions reduce both workability and the quality of the final result. When the temperature falls below the recommended range, the resin and hardener become thicker. Before use, both components should be preheated to at least 15 °C. All materials that come into contact with the resin system must also be at or above this temperature to prevent the resin-hardener mixture from cooling below the recommended level during use. The slow hardener is used when longer working time is needed or when the temperature is 25 °C or higher. It is recommended for use in fairing and profiling compounds when the temperature exceeds 21 °C, and always when the layer thickness is more than 10 mm. The minimum working temperature is 5 °C, but consult the distributor before using the product under such conditions.
Property | Resin | Fast hardener | Slow hardener |
Mixing ratio by volume | 3 | 1 | 1 |
Mixing ratio by weight | 100 | 29 | 29 |
Viscosity at 25 °C, cP | 592 | 620 | 250 |
Viscosity at 15 °C, cP | 1708 | 1680 | 570 |
Viscosity at 25 °C, cP mixed | 971 | 760 |
Working at 20 °C |
Fast hardener
|
Slow hardener
|
Gel time (thin layer formed) | 1 h 33 min | 2 h 21 min |
Pot life (150 g) | 30 min | 1 h 15 min |
Surface dry | 2 h 45 min | 4 h |
Sanded/roughened | 12h | 16h |
Thickness per layer | Resin consumption | Resin consumption depends on temperature, surface slope, porosity, and smoothness. | |
Layer thickness | 250 µm | n. 3 m²/kg | |
Bonding | n. 1,5 – 2 m²/kg | ||
AMPRO™ + 160 g/m² fiberglass fabric | n. 310 g/m² | ||
AMPRO™ + 300 g/m² fiberglass fabric | n. 600 g/m² |
The resin and hardener must be thoroughly mixed. It is most practical to do this in a mixing container, preparing only the amount that is appropriate for the job and can be used without rushing. The required amount of epoxy resin is approximately 1.5 to 2 times the weight of the fabric (including waste). For example, when using 200 g/m² fabric, about 300–400 g/m² of resin is needed to fully wet it out. Always follow the specified mixing ratio—do not add too much or too little hardener, as this will negatively affect the result.
The best tool for measuring is an accurate scale wrapped in a clear plastic bag. Medical syringes are excellent for measuring small amounts of epoxy and hardener—use a separate syringe for each. Once you’ve measured the appropriate amounts into the container, mix thoroughly—scraping the bottom and sides of the container with a mixing stick to ensure a complete blend. After about one minute of mixing, pour the resin-hardener mixture into a wide, shallow working container. The reaction between resin and hardener generates heat (an exothermic reaction), which shortens pot life and working time. In a shallow container, the temperature increase is much lower and has minimal impact on pot life. Temperature affects working time, gel time, and pot life: as temperature increases, these times become shorter, and vice versa. Gel time also decreases as the batch size increases. Epoxy resin will not cure if the mixing ratio is incorrect, the mixing is inadequate, or the temperature is too low.
Always start by applying resin underneath and placing the fiberglass mat on top. Begin by laminating the largest piece of fiberglass first—resin goes under the fabric. No air should be trapped beneath the mat. Air can be removed using an aluminum roller, by dabbing with a brush, or by pulling it out with a rubber squeegee. For small repairs, a brush is sufficient. For larger jobs where more than 1 m² of fabric is used, it's better to work with both a wet-out roller and a brush (and finish with a bubble roller). Additional layers of fiberglass can be laminated immediately, from the largest to the smallest piece. However, if you're working from bottom to top, it’s advisable to let the first layer cure before applying the next ones.
Curing time depends on temperature. As a general rule, curing time is halved for every 10 °C increase in temperature. At room temperature, full cure is achieved in 7 days, and at 40–50 °C in about 24 hours. It is important to note that while sufficient strength for most applications is reached after just over 24 hours of curing at room temperature, bonded joints that will be subjected to high loads must be allowed to fully cure before being put under stress.
Safety
Before handling epoxy, ALWAYS ensure proper ventilation and skin protection. Wear a long-sleeved shirt and disposable gloves resistant to epoxy (such as nitrile). Uncured epoxy resin is a strong skin sensitizer. Fully cured epoxy is not hazardous to health.
Tools can be cleaned with acetone, but keep in mind that epoxy is a very strong adhesive and sticks to almost any surface—including tools. It's best to use inexpensive tools that can be discarded after use.
AMPRO™ epoxy resin: H315 Causes skin irritation; H317 May cause an allergic skin reaction; H319 Causes serious eye irritation; H411 Toxic to aquatic life with long-lasting effects; P272 Contaminated work clothing should not be taken off-site; P273 Avoid release to the environment; P302+P352 IF ON SKIN: Wash with plenty of water.
AMPRO™ slow hardener: H302 Harmful if swallowed; H314 Causes severe skin burns and eye damage; H317 May cause an allergic skin reaction; H412 Harmful to aquatic life with long-lasting effects; P260 Do not breathe vapour; P264 Wash hands thoroughly after handling; P270 Do not eat, drink or smoke when using this product; P272 Contaminated work clothing should not be taken off-site; P273 Avoid release to the environment; P280 Wear protective gloves, protective clothing, eye protection.