Odd fuzz in a table saw cut

[augendoc]

I bought some 1/4" pine plywood from Home Depot to make a bracket for the spray booth I am working on. When sanding the cut edges I noticed a lot of fine, curly, hairy strands sticking out of the cut. I couldn't sand them off. I primed the pieces and figured the primer might make them stiff enough to sand off. Before trying the sandpaper I tried a blast of heat from a soldering rework station gun and the little strands shriveled up and disappeared, just like the stranding on a 3D print when you hit it with a heat gun.

I am an experienced woodworker and I have never seen anything like this before. My presumption is the little hairs are probably some kind of polyester or synthetic non-woven material applied to the face veneer during manufacture so it can be handled without falling apart. I do note the face veneer of this plywood was very good quality, but pretty thin.

If anyone knows for sure what this stuff is, please let me know.

 

[rharshberger]

I bought some 1/4" pine plywood from Home Depot to make a bracket for the spray booth I am working on. When sanding the cut edges I noticed a lot of fine, curly, hairy strands sticking out of the cut. I couldn't sand them off. I primed the pieces and figured the primer might make them stiff enough to sand off. Before trying the sandpaper I tried a blast of heat from a soldering rework station gun and the little strands shriveled up and disappeared, just like the stranding on a 3D print when you hit it with a heat gun.

I am an experienced woodworker and I have never seen anything like this before. My presumption is the little hairs are probably some kind of polyester or synthetic non-woven material applied to the face veneer during manufacture so it can be handled without falling apart. I do note the face veneer of this plywood was very good quality, but pretty thin.

If anyone knows for sure what this stuff is, please let me know.

Was the primer water based? Usually water based finishes will "raise" the grain causing fine hairs like that, but you probably already considered that.

 

[augendoc]

Definitely not the kind of fuzz you get from water-based primers raising the grain. Thes are like little curly wool fibers. The primer was a white solvent-based spray product. If you click on the picture I uploaded and zoom in, you can see some of the curls. It was worse before I hit it with a heat gun.

 

[Peartree]

Perhaps some weird additive in the glue between plys?