Procedure for repainting baseboard???
If the oil based paint is more glossy than satin, so if it's semi-gloss or gloss, you should dull the paint before applying new paint over it. Roughening the surface increases adhesion by increasing the surface area over which the adhesion occurs.
If the paint is oil based or even alkyd, you should be able to dull it's gloss by cleaning it with a strong solution of TSP in water. I would try doing that first before sanding the paint down. It's faster, easier, less messy and has fewer potential problems (like not removing all the sanding dust).
Also, on one forum I recall someone saying that you can permanently stain ceramic floor tiles with TSP. I don't have tile floor, nor do I use TSP often, so I don't know if this is true or not, but it's worth testing the TSP in an inconspicuous area first. Also, it may be that damage will only result if the TSP is left on the tile for a while, in which case just going over the perimeter of the floor with a sponge mop after cleaning with TSP would avoid
Probably the most invisible caulking technique you can use here is something called "sponge caulking". Buy a LATEX caulk the same colour as either the baseboard paint or the tile floor. Apply the caulk to the gap, squeeze the caulk into the gap with a dry finger, and then immediately wipe the excess caulk off with a damp sponge. The result will be a thin bead of caulk inside the joint that blends in with the baseboard or floor, so you won't see any gap between them.
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