I’m covering my kf3 wing and trying to do the best I can at keeping it nice and clean. The leading edge after I wrap the top over the bottom looks like this. It’s pretty rough even after ironing it for hours. Is this normal or do I just suck? Will the poly spray allow me to sand this smooth?
I can't see much detail in your photo. When attaching fabric on a hard surface like the leading edge, you can't have any wrinkles when tacking it down. The wrinkles only come out when heating over open areas between contact with structure. When tacking onto a solid surface it must be wrinkle free when it adheres.
You can wet sand out some dust and inclusions from Poly Spray, but not fabric wrinkles. If you can feel the wrinkles with your finger, they will be visible. Just remove and re-attach if you haven't ironed it yet. Use a body filler spreader to squeegee excess Poly Tak out and make it lay smooth.