I am a complete beginner to melt and pour soap making. I attempted today to make a layered soap. I poured the first layer into the mould, waited for it to harden then poured in another layer, waited for it to harden and poured on the final layer. When i removed it from the mould i cut it into 6 bars and the bottom layer of soap fell off each one :-( Can anybody advise me on where i went wrong please?