Tung Oil Finish

[Rex Edgar]

I looked and found an earlier discussion regarding tung oil finishing. It didn't quite answer my concern. Is tung oil the last step or does anyone recommend a top coat of something? And if it is the last step, is it necessary to reapply the finish periodically?

[Guest]

Their are two types of "tung oil" on the market

• "Tung Oil Finish" is typically a mix of oil and varnish.  It might have tung oil in it or it might not.  It is purely a marketing name.  Because it does have varnish it will seal the wood and, if you build 3 or 4 coats, it will provide a somewhat durable finish.  The varnish also helps it cure more quickly than pure tung oil. 
• "Pure Tung Oil" is 100% tung oil.  Unlike many oils, tung oil does naturally cure so it can be built up to a somewhat durable finish, but you need to apply a lot of coats and curing time for it to work.  

There is really no reason to use tung oil under a more durable finish.  On some woods (like cherry or maple) it does provide a bit more color and depth.  On lighter species (like your project) it tends to be unecessary under other finishes and can even give it a weird color.