Wood worm in Elm

[Hornbeam]

A friend an I have obtained about a dozen large air dried 2" elm slabs . Probably about 24 cuft in all.
Problem is that there is definitely some form of active worm which needs treating
Question. What are the best treatments and do these affect any future treatment
Plan at the moment is to give a very quick surface plane to see where its affected and then treat as required
Any suggestions on treatment
Thanks
Ian

 

[johnnyb]

Cut off all the sap and bark and burn. Then steam or freeze(freezing is 2 step). Maybe then use chemicals. It's a real pain with elm( and beech)