Howdy folks! My first post. I'm a tyro when it comes to woodworking. Still setting up my shop. Finally have it to the point where I can use it some. I'm making a Toddler Town Car for my 15-mo-old granddaughter. It's s4s oak from what ya'll call a borg. Here's my question: The finish will be rattlecan Satin poly. Should I use a sealer of some sort first? If so, what do you recommend? Thanks for any and all responses.