The filler has now cured rock hard, so it is time to start sanding. I used a cork sanding block with some 120 grit to get started on the outer surfaces, and a piece of round dowel with 120 grit to work on the finger grooves.
The inner (concave) surface was not so easy. If I use my hands, the paper will tend to follow the undulations, so I needed a block which would sand the surface smooth. I made one up using multiple pieces of balsa wood and some super glue. I held the balsa against the surface and then trickled in a little bit of glue. After 4 layers I had something which was stiff and held its shape.
It was now time to start sanding. I started with 120 grit all over, and used a knife to trim the filler around the chrome rings. Sanding around the chrome rings was really difficult – I now understand why Pearlcraft remove them.
After 120 grit, I moved to 240, 320. I could see a couple of low spots on the wheel, so I stopped sanding and filled the low spots.
After curing time, I started sanding again, this time following on from 120 to 240, 320; and then switched to wet sanding using 600 & then finally 800. There was a lot of sanding, especially around the back of the wheel where the finger grips are. I would estimate that I spent a total of 6-7 hours sanding the wheel! Not sure how well it shows up in the pictures, but the surface looks pretty darn good.
Next step is to have the wheel painted with Epoxy Primer followed by a primer surfacer. After this I will get the opportunity to do some more sanding.