wet foam in stringers

[bibijawa]

After grinding the inner sides of the stringers to prepare the area for the new fuel tank slats I'm going to glass in, I noticed water leaking out of a couple of areas where the woven roving was delaminating. My stringers apparently have wet foam. Since I'm not removing the deck I won't have access to the stringer tops. Will it be structurally safe to remove the sides of the stringers to remove the foam then glass those same skins back on?