My prop is a three bladed AeroComposite prop. The spinner was included with the propeller purchase. I decided to eliminate the screws on the outside of the spinner. To do this you need to make an internal flange inside the spinner to attach the spinner to the backing plate.
After trimming the spinner to fit over the propeller, I placed the spinner on the bench. After waxing the inside of the spinner and the inside of the backing plate, I layed up 4 layers (3.5 x 35") of 7oz fiberglass. By reaching through the hole in the backing plate and the prop cutouts I could position the glass inside the spinner.
After about 4 hours, I took a sharp box cutter and removed the glass that was intruding into the prop cutouts. After a full cure, I removed the spinner from the backing plate. I trimmed the new bulkhead down to 1" around the circumference of the spinner. I installed 16 nut plates in the new bulkhead. The spinner close outs were riveted to the backing plate