Q&A for How to Varnish Wood

Whenever you paint over something that has a clear oil based finish on it, you have to roughen it up. You can use a standard 220 gti sandpaper for the whole thing. If it's a small piece of furniture that has a lot of curves and edges on it, try using a hand sander to make sure you roughen up all the surfaces.

Yes, but it would have to be an oil-based varnish.

It depends on the product you use. Read the application instructions to see what the recommended maximum overcoat window is.

You could varnish it, but since it's a kitchen island, the varnish finish (meaning that shiny look) might not last very long undamaged with every day wear and tear. I would recommend polishing it with wax instead, which would not stop you from using your kitchen for several days and would still give you that shine. You could use something like feed-n-wax or briwax. This would also protect the wood from damage.

Marine varnish is an outdoor varnish - it holds up to UV rays well, but it will eventually start to peel off. Brands of marine varnish like Cetol will wear down but not peel, and are usually expensive.

You will need 2-3 coats of varnish. Apply them on top of each other after they dry. Sand down the final product and you're finished.

For this particular project, the wood needs to be flat. However, wood does not always need to be flat to varnish.

You should sand down the unwanted layer before you add the new one. After this, apply the first layer of your chosen varnish and let that dry. Sand down the new layer after it drys and apply a new one. Do the same after that, and you should have a neatly-varnished piece of wood.

You can try lightly sanding the wood, with a grit no lower than 500 (I used 1000). Note that it will slightly thin the finish.

Between 2 and 4 for a hard wearing finish. Sand lightly between each coat, leaving the final coat untouched.

Use a nice soft brush to achieve this. You can even use sponge brushes for a nice brushstroke-free finish.