# Filler that takes a Tung oil finish



## dogeconomics (Mar 30, 2016)

Hello everyone. New member and carpenter reporting in. I have this sailboat project. The plan is to use pure Tung oil instead of varnish as waterproofing for wood that will not be underwater long-term, though Tung oil has been used in that regard for millennia. My question is about what kind of wood fillers will take the oil. Nothing structural, just filling small nicks. I initially used some JB 8257 Kwikwood as recommended by some sailing peers, but it shows right through the oil. I've posted in some sailboat forums, but they don't seem to have answers and are more interested in telling me that spar varnish is the ONLY WAY. I've done a bunch of research on the stuff, and have decided to move ahead with the Tung oil, if only as an experiment.

So I turn to you. What filler can take oil? The wood is Teak, Cedar, and another type of conifer.

With gratitude,

Chris


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## Steve Neul (Sep 2, 2011)

I don't have experience with boats but I think Famowood putty would accept tung oil alright. It's pretty porous.


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## Tony B (Jul 30, 2008)

Famowood will not accept stain which is an oil of sorts so I doubt it would work on tung oil. Lots of fillers state that will take stain but I have not found one that actually will.
I have not found any oil that will work on exterior wood for waterproofing on boats. The only reason it was used for millenia is because that is all they had. 
Walk the boat docks and look at all the boats and the condition of the teak. The oil treated ones can be spotted from a distance due to the weathering and rot. The ones that had always been treated with varnish can also be spotted from a distance due to the rich color and health of the wood. I have worked on boats most of my life and I know for sure what didn't work. 
Find a boat with a teak deck in the southern climate that is more than 20 years old and only treated with oil and I will show you a rotted deck. Varnish also protects the bungs from leaking and this leaking is a major cause of deck failure. 
When initially purchased new, teak decks are very, very expensive. Due to lack of proper maintenance, like using oil for protection instead of varnish, the teak boats are way lower in value.

BTW, what sailboat do you have?
My last one was a 39 Allied Ketch.


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## Tony B (Jul 30, 2008)

About the best way to hide the patches is to use something like Marine Bondo and then go back and paint the patch with a color as close to the surrounding wood as you can. Then carefully paint in some grain with a picked apart paint brush.
The patches dont really seal well either. The wood expands and contracts with the seasons much more than the filler does. Some patches last longer than others, but eventually they will crack and separate from the wood.


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## Ghidrah (Mar 2, 2010)

Howzabout making oriented teak butterfly/plug inserts with a temp and then route them in.


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## Tony B (Jul 30, 2008)

That would solve the problem of looks. just be careful to figure out the stresses in that area and make sure you didnt weaken it. 
In the boating world, many patches are made by using a "Dutchman". A Dutchman is made by carefully cutting out a section of bad wood and making a piece to glue/epoxy in to replace what is necessary. Most often the shape looks like an inverted triangle being relatively long and usually not that tall. Then you simply finish that piece along with the rest of the spar, rail or whatever. The standard with joining wood at an angle is 12 to 1 to get a really safe patch. So if you dig out some rot 1 inch deep, your dutchman should be 12" long on each side of it. This is for structural or load bearing work. 
If it's purely aesthetic like filling a screw hole, just taper the hole and filled with a colored epoxy to match.
If you need more help, post a photo

Good luck

Tony B


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