Ferpol 100 BSX15 DCPD is a pre-accelerated polyester resin formulated with low styrene content (DCPD technology), designed for hand laminating and repair of fibreglass-reinforced polyester parts. Its low styrene emission makes it easier to work with in areas with limited ventilation, and its pre-accelerated state simplifies the process: you only need to add the catalyst to get started.
Technical specifications
| Parameter |
Value |
| Type |
DCPD isophthalic polyester resin, pre-accelerated |
| Application |
Hand contact laminating |
| Colour in liquid state |
Light brown / reddish |
| Colour after cure |
Purplish |
| Mix ratio |
100 parts resin : 1.5 parts catalyst (by weight) |
| Catalyst range |
1.5 – 2.0 % by weight |
| Working time |
~20 minutes at 20 °C |
| Cure time |
~1 hour at 20 °C |
| Styrene content |
Low (DCPD) |
| Presentation |
1 kg, 5 kg, 25 kg |
What it is used for
Ferpol 100 BSX15 DCPD is designed for the manufacture and repair of fibreglass-reinforced polyester parts using the hand laminating process. Its low styrene profile makes it suitable in contexts where reducing volatile emissions is a priority without sacrificing the mechanical performance of a standard laminating resin.
- Repair of fibreglass swimming pools (cracks, perforations, degraded areas)
- Repair of bumpers, underbody panels and motorcycle fairings
- Manufacture of laminated shells and structures with surface veil or glass mat
- Reinforcement of existing hollow polyester parts
- Construction of rigid back-moulds to support silicone moulds
- Prototypes and production parts in fibreglass composites
- Laminating work on small boats and nautical components
How to use it
- Prepare the surface: sand the area to be treated until the contaminated surface layer is removed and the glass reinforcement is exposed. Clean thoroughly with a dry cloth to remove dust.
- Apply release agent (if using a mould): for mould work, apply 3–4 coats of release wax and allow to dry between coats. If you are going to apply gel coat, apply it first in a uniform layer of 0.5 mm and wait until it is solid but slightly tacky to the touch.
- Weigh the components: weigh the resin and calculate the catalyst at a ratio of 100:1.5 by weight. At higher temperatures you can slightly reduce the percentage; in cold conditions, increase up to 2%.
- Mix: add the catalyst to the resin and mix with slow, even strokes for at least 1 minute. Avoid incorporating air.
- Wet out the reinforcement: place the surface veil or glass mat onto the part and apply resin with a brush or roller. Thoroughly saturate each layer so that the reinforcement is completely wetted out.
- Remove air bubbles: run the metal de-airing roller over each layer to eliminate trapped air bubbles and ensure adhesion between plies.
- Repeat the laminating: apply a minimum of 3 layers of mat + resin, allowing each one to cure sufficiently before adding the next, or working wet-on-wet if the process requires it.
- Finishing: finish with a layer of top coat to seal the surface (polyester resin cures inhibited by oxygen and leaves the last layer slightly tacky without top coat).
- Final cure: allow to cure at room temperature. At 20 °C the gel time is approximately 20 minutes and full cure is reached in around 1 hour.
Warning — polyester resin: always work in ventilated spaces. The resin emits styrene vapours even in low-content formulations (DCPD). Use nitrile gloves, safety goggles and a respirator with organic vapour filters. The catalyst (MEK peroxide) is flammable and oxidising: do not mix it directly with accelerators or store it alongside them. The curing reaction is exothermic; in large masses it can generate significant heat.
Usage tips
Temperature and catalyst ratio
Temperature directly affects working time. Below 15 °C the resin cures very slowly or does not cure correctly: in that case, increase the catalyst percentage to 2% and, if possible, work in a warmer environment. Above 25 °C the working time shortens: reduce the catalyst to 1% to gain more working margin. Never exceed 3% or go below 0.5%: at either extreme the cure will be defective.
How to achieve a bubble-free laminate
The main defect in hand laminates is air bubbles trapped between reinforcement layers. To avoid this, wet out the mat with resin before placing it on the part, apply even pressure with the metal de-airing roller working from the centre outwards, and use chopped fibreglass strands to fill corners and hard-to-reach areas. Using surface veil as the final layer significantly improves the surface finish and makes subsequent sanding easier.
Swimming pool repair: key points
In swimming pool repairs, surface preparation is the most critical step. Sand dry until you reach sound material, remove all traces of moisture (polyester resin is sensitive to water during curing) and, if the break is through-going, place a waxed sheet with a smooth surface on the outside to act as a backing for the laminate. Apply at least 3 layers of mat + resin and always finish with top coat to protect the laminate and achieve a smooth, sandable surface. If you want fillers to adjust viscosity or create filling pastes, mix with Carfer Carbonato Cristalino.
Frequently asked questions
How many layers of fibreglass do I need for a strong laminate?
For most structural applications (repairs, shells, moderate-load parts) a minimum of 3 layers of 300 g/m² glass mat wetted out with Ferpol 100 BSX15 DCPD is recommended. If you need greater mechanical strength, you can alternate mat with fibreglass fabric and finish with a surface veil to improve sealing and make sanding easier.
Why does the last layer of resin remain tacky?
Polyester resins cure inhibited by atmospheric oxygen: the surface layer in contact with the air does not cure completely and remains tacky to the touch. To avoid this, apply a final coat of top coat, which contains wax in its formulation and prevents that oxygen contact, allowing a clean cure and sandable surfaces.
What catalyst ratio should I use depending on temperature?
The standard ratio is 1.5 parts catalyst per 100 parts resin by weight. If the ambient temperature is below 15 °C, increase to 2%. If it exceeds 25 °C, reduce to 1% to extend the working time. Never use less than 0.5% or more than 3%: outside that range the cure will be incomplete or excessively fast.
Can I use this resin to make moulds?
Ferpol 100 BSX15 DCPD is formulated for laminating, not casting. For rigid back-moulds (shells) it is suitable: it is laminated over the model or over a silicone mould to create the rigid casing. For definitive casting moulds, other specific formulations are recommended.
Can it be applied over an already-cured polyester part?
Yes, but surface preparation is required. Sand the area thoroughly with medium-grit sandpaper (80–120) until it is matt and rough, clean off the dust and apply the resin. Mechanical adhesion is essential because there is no chemical bond to already-cured polyester. In swimming pool repairs, remove all degraded or damp areas before laminating.
What is the difference between this resin and an epoxy for laminates?
Polyester resin such as Ferpol 100 BSX15 DCPD is more cost-effective, cures faster and is widely used in applications such as boat building, swimming pools and automotive. Epoxy resin offers better adhesion, lower shrinkage and greater chemical resistance, but at a higher cost and with different working times. For standard repairs and production part manufacture, polyester is the usual choice.
Can I add fillers or pigments to the resin?
Yes. You can incorporate polyester-specific pigments at up to 3% by weight without affecting the cure. To create filling pastes or adjust viscosity, mix with Carfer Carbonato Cristalino (Marmolina). Bear in mind that the greater the amount of filler, the lower the mechanical strength of the final laminate.
Is the polyester resin suitable for simulating water or transparent fill effects?
Ferpol 100 BSX15 DCPD has a reddish/purplish colour after curing, so it is not suitable for transparent water effects. For water simulations or clear optical fills, there are other transparent polyester resins or epoxy resins specifically designed for that purpose, which do provide the necessary clarity.
