you must seal the back of the staves or they will crack,,and you cant do this fast enough,,better to remove the sapwood and then seal the heart wood,,its not that this spring cut wood is greener,, any fresh cut wood is green,, has to do with the sap is up in the spring and summer and down,,more sap that needs a place to exit,,if it exits through the sapwood it WILL CRACK,, the sap will look for the place of least resistance which will be the back of stave,, no; need to buy a froe just use a hatchet to drive in the staves to start the then use your wedges as normal,,when a stave is drying the mosture needs to exit the pie shaped heart wood,, to prevent checks in back,,the ends need to be sealed really good, with 3 coats of good wood glue to be sure,,,mike