I recently had a painter say to me that using the wrong grit on bare wood can release oils in the wood that make it more difficult for paint to adhere. Thus my question would be, what is the proper grit for different scenarios? E.g. - new bare wood, stripped wood, high gloss layers on old wood, on metal, etc.

I have an old Queen Anne that is in a constant state of remodel. I'm tackling new bare wood baseboard, high gloss trim and doors (with lead most certainly present), and various metal products.

I would love to not have to completely reprime the high gloss doors. I was hoping to be able to oil prime the scratches and dings and latex the rest, but did have bad luck with a latex application on other trim.

I am currently using a Sherwin Williams oil based primer, and usually Sherwin latexes, though I do love close to Home Depot and have access to. A Benjamin Moore.