I was at the store today and the label and the clerk both said to use on raw wood, and if there is an existing finish it must be completely removed. Has anyone tried it over an existing waterborne finish? I'm planning on testing the Duralaq out on a new project, but I had a few things to refinish that I was going to try and use it for as well. I would have assumed with the correct undercoat you could get it to work.