i recently found a yoyo that i lost and it was kinda scrached up
so i was thinking i can satin it
it is a raw yoyo and i only have 150 grit sand paper
so if i satin it will it be better for grinding and will it hide the scratches?

Not with 150 grit sandpaper. Well, most likely not. It should help hide the scratches though.

You can use150 grit but it is a little too coarse. It will leave the yo-yo rough to the touch. I suggest using no lower than 220 grit.

could i sand it lightly to hide scratches?

You could, but the 150 grit is going to leave a rough scratched up finish.

yeah. some hardware stores sell a pack of all kind of sand papers or u could ask for a sample. i work my way up thru the grits for 220 all the way up to 440 and polish it