Can Great Stuff insulation foam be used in a sugar maple tap hole without any damage to the live tree? I don't think so because the stuff will expand and cure to a non wet form, so the product should not be absorbed into the wood. Any thoughts? Thanks, Larry

There are products out there specifically for this purpose IF the "hole" "needs" to be filled in. Ask at your local garden center.

Tap holes are typically small. I would consider getting a wooden dowel, trimming it to fit and hammer it in.