Epoxy pox

At last, we started mixing epoxy.  Here you see a section of the float hull planking that has been filled with a mixture of epoxy and microballoons.  This makes a light weight filler that also sands easily.  Microballoons are very interesting.  They behave like a cross between a gas and a fluid.  They are so light that they tend to "evaporate" while trying to scoop, making a microballoon fog.  And then they flow like a fluid due to their microscopic spherical shape.  Definitely need to wear a dust mask or respirator when mixing in the balloons.

You can see where I filled the screw holes on the surface of the planking.  I also filled any remaining gaps between planks since a void has zero shear strength.  Of course I managed to miss one void near the aft end, so I'll get that filled when we start glassing, otherwise I would have to waste too much epoxy for a tiny gap.

We actually coated the surface with a thin layer of epoxy + balloons earlier, and then sanded prior to this final patching task.  However, in the future I would not do the skim coat, I would just do the patching.  The skim coat has to be sanded down well to ensure a good bond with the next layer of glass and epoxy.  But the bond between the epoxy and raw foam core is somewhat stronger.  The sanding is also an extra hours worth of dust generation, though I did get to try out the Tyvek suits and respirator! Should be a good bond regardless, so this was another learning experience.

While cleaning up in the evening, we had an inspector stop in to check out the surface quality.  This guy (gal?) definitely gets a better view of our work than I can.