Thanks to all who gave me advice on oil vs. water finishing coat. I've decided on oil.
But there's another problem. When I sanded the table top, the wood turned out to be not mahogany but something that was very blonde, almost white.
I used the Minwax color chart to choose a shade that seemed closest to the original.
But even when I put on two coats, the top is a lighter shade than the original. Using two coats didn't help much.
I haven't put on the finishing coat yet.
Question: Can I now use a darker chade of Minwax over the one I just put on?