Ferpol 1973 is a transparent, colourless polyester resin specifically formulated for encapsulation: it allows you to embed pieces, decorative objects and organic elements inside the cured mass with a crystal-clear finish. It is the go-to option for orgonites, resin jewellery and low-cost decorative effects, with a simple mix ratio of 100 parts resin to 2 parts Catalizador F11.
Technical specifications
| Parameter |
Value |
| Resin type |
Encapsulation polyester (accelerated) |
| Colour |
Transparent and colourless |
| Mix ratio |
100 A : 2 B (by weight) |
| Catalyst |
Catalizador F11 |
| Working time (100 g at 20 °C) |
Approx. 35 min |
| Cure time (100 g at 20 °C) |
Approx. 100 min |
| Volumetric equivalence |
1 kg ≈ 820 cc |
| Main applications |
Encapsulation, jewellery, decorative casting |
What it is used for
Ferpol 1973 is designed for projects where transparency and the ability to encapsulate elements are the priority. Its low viscosity makes casting into fine-detail moulds easy, and ensures that the included elements remain perfectly visible once cured.
- Making orgonites with crystals, metals and decorative elements embedded inside
- Resin jewellery: pendants, rings, cabochons and encapsulated pieces
- Simulating glass or ice blocks for decoration and window displays
- Static water effects in scale models and dioramas
- Fake beverages for audiovisual productions and shop windows (combined with UltraColor translucent pigments)
- Including dried flowers, insects or natural objects in decorative pieces
- Low-volume pieces requiring a transparent, cost-effective finish
How to use it
- Prepare your workspace at a stable temperature of 20–25 °C. Temperature and resin mass are the factors that most influence cure times.
- Calculate the amount of catalyst: for pieces of around 100 g use 2% Catalizador F11; for castings of 1 kg, 0.5% is sufficient. The larger the mass, the greater the heat of reaction, so you must reduce the catalyst percentage accordingly.
- Weigh the resin in a clean, dry container. Remember that 1 kg equals approximately 820 cc if you are working by volume.
- Add the catalyst in the calculated proportion and mix slowly and evenly for 2–3 minutes, avoiding the incorporation of air.
- Let the mixture rest for 2–3 minutes so that bubbles rise and are released before pouring.
- Place the elements to be encapsulated in the mould. If the object is light and may float, pour a first layer, let it gel, and place the object before pouring the remainder.
- Pour the resin slowly into the mould, tilting it if necessary so the liquid displaces the air without trapping bubbles.
- For large pieces, work in layers, allowing each one to cool before pouring the next, to avoid cracking and yellowing caused by excess heat.
- Demould once the full cure time has elapsed (approx. 100 min at 20 °C). For a definitive cure and maximum hardness, leave the piece to rest for 24 h.
- Clean tools with AC-1 acetone before the resin cures.
Warning: product with strong styrene odour
Polyester resin releases styrene vapours during mixing and curing. Always work in a well-ventilated space or with local extraction. Wear nitrile gloves, safety goggles and a mask with an organic vapour filter (FFP3 or type A cartridge). Avoid prolonged skin contact. In enclosed spaces, the odour can be very intense; use in unventilated interiors is not recommended.
Usage tips
Control temperature to avoid defects
The main enemy of polyester resins in thick castings is accumulated heat of reaction. If the resin mass is large and the catalyst percentage is high, the internal temperature can exceed 80 °C, causing internal cracking or yellowing. For castings over 200–300 g, reduce the catalyst percentage to 1–1.5% and work in layers no more than 2–3 cm thick. Allow each layer to cool completely before pouring the next.
Eliminate bubbles effectively
After mixing the resin with the catalyst, let the mixture rest for 2–3 minutes before pouring. A gentle gas torch passed at a distance over the freshly poured surface breaks surface bubbles without burning the resin. You can also place the mould under a vacuum chamber if you have one, although for most decorative pieces this is not necessary. Avoid stirring the mixture vigorously or in a circular motion; mix with slow, bottom-to-top movements.
Pigmentation and decorative effects
Ferpol 1973 accepts resin-specific pigments. For beverage effects, coloured water or translucent colour layers, add UltraColor translucent pigments in small amounts (a few drops) before adding the catalyst. For metallic or sand effects, mix Magic Powder directly into the resin. In orgonites, the bottom layer is usually pigmented or loaded with metal filings, while the upper layers are left transparent to show the embedded crystals. Adjust the catalyst percentage if you add powder fillers, as they can alter the heat of reaction.
Frequently asked questions
What catalyst percentage should I use?
It depends on two factors: ambient temperature and the mass of resin to be mixed. As a reference at 20 °C, for 100 g of Ferpol 1973 use 2% Catalizador F11; for 1 kg, 0.5% is enough. The larger the mass, the greater the heat of reaction, so the percentage is reduced. At temperatures below 15 °C, it may be necessary to increase the percentage slightly. Never exceed 3% or go below 0.5% to avoid defective cures or brittle pieces.
Can I make thick pieces in a single casting?
It is not recommended for volumes above 200–300 g. The exothermic curing reaction can cause internal cracking or yellowing in large masses. The solution is to work in layers 2–3 cm thick, reducing the catalyst to 0.5–1% and waiting for each layer to cool before pouring the next. Bear in mind that the lines between layers may be visible on vertical sides and will require sanding afterwards.
How do I avoid bubbles in the finished piece?
Mix with slow movements and avoid incorporating air. After adding the catalyst, let the mixture rest for 2–3 minutes before pouring. Pass a gentle gas torch at a distance over the surface to break surface bubbles. Pour the resin slowly, tilting the mould if necessary. If you have a vacuum chamber, degassing the mixture before pouring eliminates virtually all internal bubbles.
What type of mould is compatible with this resin?
Silicone moulds are the most recommended for Ferpol 1973: they allow easy demoulding without a release agent and reproduce every detail. Polypropylene (PP) or polyethylene (PE) moulds also work well. Avoid polystyrene (PS) moulds, as the styrene in the resin will dissolve them. Rigid plaster or resin moulds require applying a release agent before casting.
Can this resin be tinted or pigmented?
Yes. Ferpol 1973 accepts resin-specific pigments. For translucent or deep-colour effects, UltraColor translucent pigments are the ideal choice. For metallic or filler effects, you can use Magic Powder. Always add the pigment to the resin before incorporating the catalyst and mix thoroughly to achieve a uniform colour.
Does the resin yellow over time?
Polyester resins have limited UV resistance compared to epoxy resins. Prolonged exposure to direct sunlight can cause slight yellowing over time. For indoor or decorative pieces without direct sun exposure, yellowing is minimal. If you need maximum long-term colour stability and outdoor exposure, transparent epoxy resins are a more suitable alternative.
How do I clean tools and equipment?
Clean immediately after use with AC-1 acetone. Once the resin has cured, it can only be removed mechanically (by sanding or scraping). Acetone does not dissolve cured resin.
What is the difference between this resin and a laminating polyester resin?
Ferpol 1973 is formulated for bulk castings (encapsulations, embedments, transparent solid pieces) with minimal exotherm in thin layers and maximum optical clarity. Laminating resins such as Ferpol 100 BSX15 are optimised for impregnating fibreglass and working in thin layers with greater thixotropy. They are not interchangeable: using a laminating resin for encapsulation would result in a much more opaque finish and poorer results.
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