PCP Polyester Pattern-Coat Primer

Requires MEKP Catalyst, not included.

Easy Composites' PCP Polyester Pattern-Coat™ Primer is a specially formulated high-build polyester resin system designed for the fast and easy surfacing of composite patterns. The composite pattern coating resin Primer will not sag or run off the vertical sides of patterns up to a 1.5mm thick application making light work of pattern surfacing.

PCP Polyester Pattern-Coat™ Primer can be used on its own as a fast-building, easy-to-sand and adequately glossy pattern surface, ready to take moulds straight off, or in conjunction with PCG Polyester Pattern-Coat™ Hi-Gloss when a very high gloss is required.

Further Information

Directions for Use

PCP Polyester Pattern-Coat™ Primer can be applied directly to polyurethane foam, modelboard, tooling block, MDF, wood, metal and some plastics. PCP Polyester Pattern-Coat™ Primer can be applied over patterns that have been filled with polyester bodyfiller however it should not be applied to expanded polystyrene foam (Styrofoam) because it will react and dissolve the foam.

Patterns made from very low density foams (anything less than around 40kgs/m3) should be 'scrimmed' with a layer of polyester resin reinforced with a lightweight glass cloth before application of the PCP Polyester Pattern-Coat™ Primer.

1. To ensure a good bond, key the surface of the pattern using 80grit abrasive paper and remove any dirt or grease using acetone.
2. PCP Polyester Pattern-Coat™ Primer should be mixed with MEKP Catalyst at a ratio of 2% catalyst (can be adjusted according to pot-life required and ambient temperature).
3. Apply directly to the surface of the pattern by brush. Application by gelcoat spray gun will yield even better results (thin using 25% pure acetone).

Pigmented Guide-Coats

When sanding a coated pattern it is very useful to know how far through the pattern coat you have sanded so as to avoid breaking through the coating and through to the pattern material (such as foam) underneath. To help with this we recommend applying the PCP Polyester Pattern-Coat™ Primer in two layers, the first as supplied and the second layer with the addition of a 'guide coat' pigment, mixed into the Primer.

To do this, apply the first layer of PCP Polyester Pattern-Coat™ Primer as described above (either by brush or spray gun) and allow to cure to a 'B-Stage' where it is firm but still slightly tacky, before mixing pigment in with a second batch of PCP Polyester Pattern-Coat™ Primer and applying as above. This will not only result in a thicker application of Primer (allowing plenty of material to flat down through) but it will also alert you when you are down through the first layer of Primer and into the second layer meaning you can choose to stop and apply an additonal layer of Primer if you choose or avoid breaking through in thinner areas.

Flatting

Once cured (around 3hours, depending on ambient temperature) it can be wet-sanded and flatted using 120 then 240grit abrasive papers to start to develop the smooth accurate lines of the pattern. If necessary additional coats of the Primer can be applied and then flatted back until satisfactory.

Using without PCG Polyester Pattern-Coat™ Hi-Gloss

Where only a reasonable level of gloss on the pattern is acceptable then PCP Polyester Pattern-Coat™ Primer can be flatted and polished up to a smooth, medium gloss finish on its own.

1. Wet-sand using increasingly fine abrasive papers (240, 400, 800, 1200) remembering to change the water when you change grits.
2. Wait for the PCP Polyester Pattern-Coat™ Primer to cure fully (around 25hrs) before polishing using a power polisher.
3. PCP Polyester Pattern-Coat™ Primer can be finished to a reasonable level of gloss using a polishing compound such as NW1 White Super Cutting Compound .
4. Following the application of a suitable release agent (such as Wax, PVA or Chemical Release Agent) moulds can be taken directly from the Pattern-Coat™ Primer finish.

Using with PCG Polyester Pattern-Coat™ Hi-Gloss

Where a high level of gloss or harder surface is required on the pattern then we recommend finishing the PCP Polyester Pattern-Coat™ Primer to around a 120grit abrasive paper and then coating with PCG Polyester Pattern-Coat™ Hi-Gloss before flatting and polishing to a very high gloss finish.

Shelf Life and Storage

PCP Polyester Pattern‐Coat™ Primer should be stored in the dark in suitable closed containers. It is recommended that the storage temperature should be less than 20°C where practical, but it should not exceed 30°C. KEEP THE PACKING TIGHTLY SEALED WHEN NOT IN USE.

If stored under the above conditions the PCP Polyester Pattern‐Coat™ Primer will have a shelf life of 3 months, from the date of production.

Compatibility Information - Dos and Don'ts

Although by no means an exhaustive list, the pattern materials, pigments and additives listed below have all been tested and are known to work well with Pattern-Coat™ Primer.

Compatible Moulds

• Polyurethane foam
• Polyurethane Model Board
• Wood and MDF
• Polyester & epoxy based patterns after a good surface key
• 3D printed plastics such as PLA & Nylon (except ABS)

Compatible Pigments

• Polyester Colour Pigment * (for vivid opaque colours)
• Translucent Tinting Pigment * (for less vivid opaque colours)

Compatible Fillers

• All dry filler powders**

* Generally pigments are only used with the Pattern Coat System to help differentiate between layers of material when sanding.

** Although technically compatible, very few occasions would warrant the use of filler powders with a Pattern Coat System. PCP Polyester Pattern-Coat™ Primer is already heavily filled to aid application and sanding of the product.

Key Processing Information

• Ease of Use: Suitable for professional and hobby use (follow SDS advice).
• Odour: PCP Polyester Pattern Coat™ Primer has a strong styrene based odour.
• Safety Precautions: Wear gloves and goggles and work in a well ventilated area. Always read the SDS before use.
• Ambient Conditions: Can be used from 15 to 30°C although pot-life and cure time will be affected significantly. Recommended working at an ambient of 20-25°C.
• Degassing: Not necessary in most cases. Simply mix and use.
• Mix Ratio: Add MEKP Catalyst at a ratio of 2%. Use digital scales.
• Shelf Life: The resin and hardener has a shelf life of 3 months from the date of production.
• Mixing: Mix thoroughly by hand for at around 2 minutes.
• Application: Can be applied by spray gun or by brush. Maximum thickness per layer 1.5mm.
• Pot-Life: The pot life at 25°C is 15 minutes. When sprayed diluted with acetone as per TDS, pot-life is extended to 30 minutes. Be sure to use your resin before this time.
• Exotherm (Over-Heating): Resin will heat-up whilst it cures. Mix in small batches and use expediently. Mixed resin in a pot will quickly overheat (exotherm) and can smoke/ignite. Never leave mixed resin unattended.
• Cure Time/Overcoating: At 25°C you can expect the Primer to be ready for overcoats after 2-3 hours when at the firm but tacky stage of cure. The Primer will be ready for sanding after 12 hours and should be allowed 24 hours before machine polishing.