I'm sure others with more experience can provide more info. However, here's what I did for a coffee table that's 40 x 40 with some modifications since I went for a satin finish. I started with Zinser Sealcoat. Then, since walnut is an open grain wood I used Solarez grain filler to get a smooth finish. (I Can’t Believe It’s Not Lacquer ~ Grain Sealer Formula ~ (4 Oz.) No Odor - No Waiting - Cures 3-5 Minutes!, Eco-Friendly, Zero VOC's, Perfect Sanding & Made in The USA! - - Amazon.com
) It's not cheap but very little goes a long way. It took 3 coats, applying it with a credit card and sanding with 400 grit between coats, but I had it done in an hour since the UV cure (sunlight) is fast. I then put 3 coats of Zar Satin Poly, sanding between coats. The first coat I put down full strength, the last two I cut it with 50/50 with mineral spirits to make it a wiping poly.
Since you're going for a glossy finish, and want to show off the grain as much as possible, I would use gloss for every coat. Semi-gloss, satin and matte finishes have flatteners in them which do effect the clarity to some extent.
As I said, this worked for me, others may have better approaches.
) It's not cheap but very little goes a long way. It took 3 coats, applying it with a credit card and sanding with 400 grit between coats, but I had it done in an hour since the UV cure (sunlight) is fast. I then put 3 coats of Zar Satin Poly, sanding between coats. The first coat I put down full strength, the last two I cut it with 50/50 with mineral spirits to make it a wiping poly.
Since you're going for a glossy finish, and want to show off the grain as much as possible, I would use gloss for every coat. Semi-gloss, satin and matte finishes have flatteners in them which do effect the clarity to some extent.
As I said, this worked for me, others may have better approaches.