I bought a new stator to replaced the ruined one (from the last owner) of my 657 SPX, and am wondering what the coating is on the factory ones:

Click image for larger version. 

Name:	!BkhSFLwB2k~$(KGrHqYH-CIEtH5Yfp-mBL(3dlQ!BQ~~_12.JPG 
Views:	64 
Size:	21.3 KB 
ID:	204577

The new one I bought isnt coated, so do I need to coat it?