EPP ( Expanded Polypropylene, ) Foam

EPP stands for Expanded Polypropylene, and though its just another kind of packaging material, Its great for building model airplanes because, it is light, strong, and moderately flexible making it a very resilient material.

Technically, its a highly versatile closed-cell bead foam that provides a unique range of properties, including outstanding energy absorption, multiple impact resistance, thermal insulation, buoyancy, water and chemical resistance, exceptionally high strength to weight ratio and 100% recyclability.

EPP foam is incredibly tough and makes durable planes. When bent, it doesn’t break. You can literally bend it all the way and it will not break.
When crushed or pressed, it heals itself and returns to its normal shape when you release the pressure . When EPP is torn, the two halves match up perfectly and can be re-glued with an almost invisible repair. Models built out of EPP foam are extremely durable and can take up a lot of abuse as the foam bends without breaking.

Another thing thing that makes EPP great is that, it is CA compatible. This makes the builds pretty light, as you do not need to rely on the heavy Hot Glue and epoxy, and also speeds up field repairs.

EPP Cuts easily and cleanly with a sharp knife. However EPP foam is quite difficult to sand.

EPP Foam cuts super well with a Hot Wire, thats what we are going to do – get some beautiful wing cores and airfoils out of this material.

Due to its flexible nature, Models built out of EPP foam are usually strengthened with carbon fiber strips rods and stringers, Its also good to use some strapping tape ( or fiberglass tape ) to laminate the critical areas of the model like the leading edges and the area around the motor mount.

At Vortex-RC We have got some lovely 50MM Sheets of EPP In both Black and White in Colour. The density we have is 30Kg/m3 which is best for making RC model planes.

The size of our blocks is 1000mm in length, 650mm in width and 50mm in thickness.