Yes, Spar varnish is a marine quality exterior varnish that can be used over many surfaces, however it does have an amber hue that will affect the color of whatever surface is being coated. If you're looking for a long-lasting crystal clear coating then a better choice would be a water-based polyurethane coating.
Yes, but why waste the varnish. - (it is meant for bare wood )
Yes, you can.
Lacquer can cause the paint to bubble or crack due to the very hot solvent that is a part of lacquer. If you want a clear coat over paint, a better choice is spar varnish over oil base paint and arcylic urethane over latex.
Yes, you can.
Paint can be applied over varnish, but it needs to be a compatible type of paint for the type of varnish, and the surface needs to be prepared by removing loose material, dirt and sanding. If it is not a compatible paint the surface needs to be etch primed. Contact a local paint supplier for advice.
Since the definition of spar is a pole that supports the sail of a ship or boat, the antonyms of spar are the antonyms of the synonyms of spar. Some synonyms are rod, rail, and varnish.
It's a very good marine quality varnish.
That is not generally recommended.
I would use an exterior polyurethane. It is going to hold up better and be more flexible than a varnish. Polyurethane has taken over the varnish market--it's hard to find any other kind. There is a "spar polyurethane," which is what you should use on the item in question.
Yes, but I usually sand it lightly first.
Usually yes. You'd be advised to use a water based varnish, and rough up the paint a little before coating.