Hi Carl

 

Thanks for the report.  I suppose nobody will remember but did somebody just oil the air grinder prior to grinding?  Another thing that can happen with dense layups like the glass prepregs we use.  A dull grinder disk can burnish the edge of the area being abraded making it less likely to adhere.  the close up photo's did show the unbonded areas with the voids.  Any estimates as to the void area like was it 75% bonded with 20% voids or was it 50-50 or ???.

 

Also, are all of the fast build wing close outs done with Jeffco and not Hysol?

 

Great report!

 

Dan