Not everything goes according to plan! Here are a few examples of that rule...
Case #1 - Router Mount....
Foamy is all ready with sprues glued on
Melting some AL
Pouring some AL
ConclusionI think what's happened here (and happened many times before for me) is the adhesive I was using to glue the sprues onto the foamy was melting the foamy at the joint causing a hard area that was not allowing the AL to flow and it blew out the side of the sprue and sand...
So the very next thing I tried was to actually cut the sprues when I cut the foamy
New foamy with sprues part of the design!
ConclusionI think on this one I just didn't have enough aluminum and I didn't pour fast enough