Exofeed AL414 1kg
(keeps risers hot allowing molten metal to pipe/draw into the casting and prevents shrinkage faults)
Exofeed Al 414 is a fast firing metallic grey powder of medium bulk density.
Exofeed Al 414 is a high quality, low hazard, exothermic hot topping compound for use with
aluminium alloys and aluminium bronzes.
Ignition of Exofeed Al 414 takes place a few seconds after application to molten metal,
producing very high temperatures and forming a self supporting, insulating crust. The rate of
application and the layer thickness applied can affect ignition time; ignition will be quicker if
the product is applied slowly, or as a thin layer.
Exofeed Al 414 generates modest levels of fume and smoke due to a controlled rate of burn.
Exofeed Al 414 is best suited to small sized risers and applications where rapid ignition of the
product is required.
Apply Exofeed Al 414 to form a complete layer on the riser or feeder head immediately after
casting to reduce heat loss.
On small riser sizes, up to 70mm diameter, we recommend a layer thickness of 10-15mm. On
risers of 70mm-200mm we recommend a layer of 15-25mm.
Exofeed Al 414 has high calorific values and can be used on large risers, but more insulating
grades of hot topping with a slower rate of burn may be more suitable for this application to
keep smoke evolution to a minimum.
No benefit is obtained by using an excess of this product since this slows down ignition and
could result in the feeder head sculling over.
However, many times it is easier to just fill a container and dump the topping on the metal in the riser after the mold is poured. Instead of having a different container for each riser size, typically a common container is used for all sizes. If less topping is needed for a smaller riser the decision is left to individual discretion. If more is needed, multiple scoops of hot topping may be applied. Rarely is the amount of hot topping optimized for the specific riser in which it is applied.
The time between when the metal enters the mold and when the hot topping material is applied is critical. If too much time elapses, a skin can form on the top of the riser, reducing its ability to pipe down and feed the riser. An inadequate amount of hot topping material can cause a similar problem.