Written by Lu Allington-Jones, Senior Conservator, Natural History Museum London
Epopast 400 is an excellent material for creating supports for heavy specimens. It is a 2-part mixture of a liquid and a fibre-glass putty that has passed accelerated ageing tests. The dough-like mixture can be applied to robust specimens and allowed to dry over night to create a rigid support which allows even distribution of weight and prevents point compression damage.
Presented below you will find a video of how to make support mounts out of Epopast 400, plus some practical tips and things to consider. But first some examples of the uses of Epopast 400 mounts:
This film stars the elusive @StoatsMcGee and the femur of Loricatosaurus priscus, holotype stegosaur NHMUK PVR3167. ©The Trustees of the Natural History Museum, London.
- Even distribution of weight.
- Easy manoeuvring of heavy specimens.
- Light weight but not brittle like plaster of Paris or Jesmonite.
- Adaptable for display mounts.
- Fresh Epopast can be added to cured Epopast at any time.
- Good for transportation of specimens.
- H&S issues of Epopast itself – corrosive, sharp edges.
- Physical mixing can be tiring.
- You tend to run out of catalyst if you don’t measure it carefully.
- H&S of grinding the sharp edges down (excellent dust extraction is required). An alternative to grinding the Epopast is coating the mount with a smooth layer such as Tiranti multipurpose polyester resin with a slate filler.
- Very messy – but can be cleaned up with IMS and tissue before it dries.
- Cling film barrier layer(s).
- Modelling clay for undercuts.
- Relic WrapTM (polytetrafluoroethylene film) or aluminium foil barrier layer.
- Epopast 400.
- Grinding equipment or polyester resin for creating a smooth finish.
- Plastazote® 2 mm for lining finished mount (if you want to use 10 mm foam lining, lay a 10 mm layer of modelling clay between cling film layers on your specimen to create a contoured void to accommodate it).
- Hot glue for attaching Plastazote®.
- Acrylic paint.
- PPE (disposable nitrile and marigold gloves, Tyvek® sleeves, lab coat, safety spectacles for mixing). Please always check the manufacturer’s most recent Safety Data Sheet before using any chemical.