i have applied 4 coats of poly to a neck and have sanded with 0000 steel wool between each coat. question is how do i finish my last coat so it looks glossy and smooth? if it was laquer i would know how to polish it. poly no idea. what to do?

You can polish out poly in the same way you would polish out lacquer. Just use progressively fine polishing compounds.

My recommendation, however, would be to sand your current finish to satin, but as smooth and level as you want it to be. This will ensure that you have a completely level undercoat. Then, apply one more poly coat, and rub it out to satin with 600 - 800 grit sandpaper. From there, move up to 1500 and 2000 grit paper, and then pulishing compounds.

Alternately, once you get it smoothed up to 800 grit, you could use wet (soapy water) MicroMesh cloths, which go form 1500 grit up to 12000 grit. This would give you as close to a mirror finish as I think you will see.

thank you very much for your reply and advise.

I'm very fond of the MicroMesh polishing cloths... I have a set i use dry, and a set I use wet. I also have a set specifically for my random orbit disc sander, which works either wet or dry.

i have a set of six of the cloths from micromesh. i use them on my model cars. never thought to use them anywhere else. thanks again. the hard part is goin to be between the frets. i reckon im gonna be at it a while. i want the neck to look like my geddy when finished.