I'll have to invest into setting up a pit like that sometime.It looks productively very efficient.I totally agree heating those white woods is a game changer.
No worries about hijacking here.Subject is totally related.Would like to see others' elm staves from other areas identifying there logs.
I tend to make 1 bow at a time.Not always the same length or design.I do have shelves full of forms though.
Nice looking clean logs there.Being 8" diameter you should get a fairly flat back on those.Your grain on the 1 log does looks mildly wavy.I did'nt see that much wavyness on my logs grain though without a knot.Personally I would follow that wavy line.Layout for a heck of a snaky character bow there.
I kerfed mine about 1.75" deep.
Some of my staves have a little sprig of a twig about 1/16" in diameter[no wave from that].Not really even a knot.Where there was a knot on the edge of the stave after cutting through it there is a mild wave but since the staves are so wide it should'nt affect the layout of the bow any.There were'nt many knots on my staves overall.A couple of the sapling staves do and 1 of the shorter staves does.
Length on most of the staves from 69" to 64" on most with 4 staves at 58" long.Total of 20 staves.
There is a fair amount more heartwood in your log.In the states here they catagorize slippery elm as a soft elm.[red,chinese,and american]They catagorize the hard elm as rock,winged,cedar,and even september elm.
These elm differences in hardness are a lot like maples here.We've got hard and soft maple trees too.
After removing the bark on my staves/letting them dry/shellacking them the color on the back of the stave turns a medium brown.You can see the difference from wiping the sap off before applying shellack and not wiping the sap off as to the dried color.
I think I'll end up removing 1 ring from most of these staves.They've got good consistent rings on them.The drying twist is what I hope to avoid with these staves.
It's still a gamble though retrieving staves from logs.Part of the adventure.