Sadie-f
Senior Member
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- 427
Having completed at least rev-1 of my tung-finished guitar, I wanted to clarify some misunderstandings about pure tung oil. The pinned post in the finishes forum is great, I have one pint to better clarify:
I think it's more accurate to say they're not built up to film-forming more because that would require a completely stupid number of coats. My experience with tung has been it's quite a bit harder than traditional varnishes, to the point of being almost brittle, if you scrape a tung finished surface, it comes off like a powder. On the flip side, small scrapes are very easy to repair. Because it's so thin, just clean the damaged spot, wipe on a bit of tung and wipe it off later. such blemishes may be visible, imx they're hard to spot.
By comparison, if you scratch a varnished surface, sometimes you can buff it out, however, to get back to original, you pretty much need to lay down new to the entire part, or accept a visible brush - in.
My main experience with varnish finishes has been applying traditional spar varnish to spruce for masts etc in marine use. The best of these all have some tung oil, in addition to other resins (usually phenolic, sometimes alkyd). I've also sprayed / brushed iso-cyanate paints on boat hulls, All these finishes live outdoors and the marine paints are more or less interchangeable with what auto manufacturers use.
Many members here question the water-protection from oil finishes. My first experience with tung was a dining table and chairs I refinished in pure tung and that finish was still in fine shape 20 years later, including children, projects done at the table, etc.
To get that protection, you want to get out to at least a half dozen layers, for that table as well as the new Strat build, I went to 15 & 20 respectively. It's definitely more time consuming than laying down spray or brush varnishes, and you have to be want to see the still-visible grain. I suspect to get completely past that in most woods would run out to 100 layers, at which point it would probably look like a finish you could achieve with a couple of layers of spar varnish.
These oils are usually not built up with enough coats to form a surface film, like that of varnish or lacquer, because the film is too soft
I think it's more accurate to say they're not built up to film-forming more because that would require a completely stupid number of coats. My experience with tung has been it's quite a bit harder than traditional varnishes, to the point of being almost brittle, if you scrape a tung finished surface, it comes off like a powder. On the flip side, small scrapes are very easy to repair. Because it's so thin, just clean the damaged spot, wipe on a bit of tung and wipe it off later. such blemishes may be visible, imx they're hard to spot.
By comparison, if you scratch a varnished surface, sometimes you can buff it out, however, to get back to original, you pretty much need to lay down new to the entire part, or accept a visible brush - in.
My main experience with varnish finishes has been applying traditional spar varnish to spruce for masts etc in marine use. The best of these all have some tung oil, in addition to other resins (usually phenolic, sometimes alkyd). I've also sprayed / brushed iso-cyanate paints on boat hulls, All these finishes live outdoors and the marine paints are more or less interchangeable with what auto manufacturers use.
Many members here question the water-protection from oil finishes. My first experience with tung was a dining table and chairs I refinished in pure tung and that finish was still in fine shape 20 years later, including children, projects done at the table, etc.
To get that protection, you want to get out to at least a half dozen layers, for that table as well as the new Strat build, I went to 15 & 20 respectively. It's definitely more time consuming than laying down spray or brush varnishes, and you have to be want to see the still-visible grain. I suspect to get completely past that in most woods would run out to 100 layers, at which point it would probably look like a finish you could achieve with a couple of layers of spar varnish.