mmmm why

[oldskoolron]

ok so im like pete o first time casting .no problem with my furnace melts ally brass easy as but done a pour and ended up with a heap of micro holes
made a couple small cylinder type moulds in my flasks done everything ive watched been told ect an they came out good not great but thatl come with practice I spose .
ok so had alloy in my 1kilo gas bottle made crucible and was melting great added some Epsom salts wrapped in ally foil also added some washing soda wrapped in ally foil then once all were melted I scrapped dross of the top and poured .betwwen having the last bit of ally melt and turning off the gas was about maybe 7 to 12 mins maybe a flyshit more .so poured the ally and went in great let cool for 30 mins then broke open .geez the moisture in my greensand really drys up .put the rough bits in lathe and took a few skims off
after first cut I noticed some holes so went deeper but they are all through the ally
what do you ppl think I done wrong would like to sort it as I have some pattens I made of twincam rocker boxes to fit evo
cheers in advance for the help/advice
below the bits n holes