Chestnut End Seal

End Seal is an emulsified paraffin wax used the seal the ends of freshly cut timber to slow down the drying process and reduce the risk of the timber splitting.
It can also be used on work-in-progress that is being left unfinished where there is a risk of the timber splitting.

Apply it liberally, normally by brush but it can be sprayed if needed, usually to the smallest surface of the timber which will normally be the end grain where moisture is most likely to escape from. Sealing the surface will encourage the moisture to escape via the larger areas which will result in a slower exit.