I had a crackling sound when I walked on deck, around the right side of the cabin top, behind the chainplate. I researched how to fix it and I came up with the only complete solution. Cut the top skin off, recore if needed, then glass the top back on. I drilled some holes to check the core. The wood came out dry. I assumed it would be a pretty straught forward job. It had to be easier than recoring the primary. Wrong.
I marked the dull drum sound areas and had a perimeter. I then used my angle grinder with a cut-off wheel and make my cuts of the top skin. I made an extra cut along the bottom to use as a sacrifical piece, so I could more easily pry up the skin and save it. I figured delamination meant easier skin removal. The skin was a pain to get off and I quickly realized there was no top skin to core delamination. I then assumed I had bottom skin delamination, because when the skin was removed and I put pressure on the core, I could still hear the sound. Damn, somehow the bottom skin has delaminated. I then did some core removal with the intent of just replacing the whole section with new balsa and glassing it all in.The bottom skin wound up being securly laminated. What the hell is making that flexing, crackling sound? Turns out it was a slight flexing of the deck core putting pressure on a piece of molding in the cabin. I went below and pryed the peice of moulding off and the sound stopped. No problem I figured, I'll just clean up the core, replace the areas I removed, and glass the skins back on. When it cures I'll glass the seams properly. I mixed up the west system, thickened it, prepped the balsa, prepped the site, and properly recored the area. I topped the site with release fabric. I placed thin plywood over the site and topped the repair off with heavy trash bags filled with sand.