OK, I have a shelf that my dad made a long time ago and I've decided I want to change the stain color. I first tried a stain called PolyShades directly over the old stain and that didn't look good at all. So, I scraped all of the old stain off and started over. We'll, I didn't do a very good job of sanding after I scraped and so when I added my new stain, it didn't look good at all.
My question is, can I just sand over the stain I just applied without having to strip or scrape the stain off? Or do I have to strip it first and then sand again?