I have 3 cypress knees that I got at a yard sale. They are all natural and have not had anything applied to them. The family I got them from said they were at least a 100 years old. They are 30”, 24”, and 20” high with a good wide base. I have been soaking them in a 55 gallon drum for 3 months and they still float easily. I knew that aged cypress is more difficult to sink but it’s illegal to cut cypress knees(since the 60’s) in most states so cypress knees are hard to come by that are not old. Any ideas to help get them sunk? The 2 bigger ones are bigger than I can boil.