Just a recommendation to try something different than the spray fixative .... try using clear PVC cement. You may be surprised at the results. I went to a fly tying session last year in West Yellowstone by Whiting (the feather people)and they shared this technique with us. They used the clear PVC cement on entire feathers which they used as down wings on all types of flies, hoppers and stoneflies. They used small feathers and a 8" x 8" piece of tile. They placed the feathers on the tile's perimeter and then using the PVC swab coated (soaked thru) each individual feather on the tile. Performing this task adhered the wet PVC soaked feathers to the tile. After drying the feathers were then stripped from the tile by pulling on the feather's stems. Some minor trimming and the feathers were ready to go.The PVC dries relatively quickly and produces an extremely strong bond with the feathers. Some feathers could not be torn apart. This technique was new and very intriguing to me. I believe the same can be done with the turkey feathers and the result will be water proof. Give it a try you might like it.