Here is one of Walt Shultz in a mild chop.LOLHere is one builder's video on hull coring. Walt Shultz of Shannon in Bristol RI. He started coring in 1981 and has switched to close-cell foam. The video is long but he addresses the coring issue in the first 7 minutes. Note that an important point is the fumes created during production that is faster than the slower way Shannon builds. At any rate, I found this quite enlightening.