# how to fix tung oil seeping up from cracks in wood while drying



## therabidrabbit (Dec 16, 2013)

I am attempting to finish a slab of wood with tung oil for the first time and of course I am having a problem.

I am useing polymerized tung oilk from lee valley and am applying to to a 2" sycamore slab.

The slab itself has a bunch of cracks which i didn't mind asthetically, i just wanted a smooth surface.

I applied the first coat sealer, no problems. Waited 24 hours til it felt dry and looked good, applied the second coat 50/50 sealer/tung oil.

when I went back a day later to check on it I noticed the oil seeping up from all the cracks. The rest of the surface is dry but the spots you can see seeping up which feel slightly thicker are still a little tacky.

SO my question is what can I do about it? I was thinking maybe just wait a couple more days for even the thick spots to harden then sand or steel wool them back down until smooth and reapply a few more coats of oil…. but I don't know how to keep this from happening again or if this will even work.

I guess I probably should have filled in all the cracks beforehand but I"m hoping that was not necessary.

Link to wood photos:


http://imgur.com/rx9f0QZ


Thanks for help!


----------



## ClintSearl (Dec 8, 2011)

What's the "sealer?"


----------



## therabidrabbit (Dec 16, 2013)

it's the Lee Valley PTO sealer. I think it's just 80/20 oil/mineral spirit or something similar.


----------



## knockknock (Jun 13, 2012)

I use the pure tung oil (no driers or solvents), so I don't know if this applies. I buff with a cloth an hour after applying, then again a couple of hours later, and again the day after applying, and there can be a little seepage.


----------



## wormil (Nov 19, 2011)

Keep buffing and wait or you can apply a sealer coat of shellac, not necessary for the oil to be dry.


----------



## therabidrabbit (Dec 16, 2013)

So I should keep buffing until it feels smooth (but visually i will still be able to see where it seeped up, the difference in sheen?) and then keep applying coats the usual way, and it will eventually even out and look fine? (assuming I give enough drying time between coats)


----------



## hydro (Aug 9, 2013)

That is typical of any penetrating oil finish, and worse with the ones that take longer to set up (plain tung oil). I normally use the Watco oil as it has dryers that speed the setting process, but still see bleed out on open grained wood or where there are hidden cracks. Here is what you can do:

1. On the first coat, apply the oil finish then come back every couple of hours and gently wipe off the bleed out areas. Do not rub vigorously as that will create heat and cause the problem to worsen. It will take time, so be patient. This first coat serves as a sealer. You do not need commercial "sealer" products with oil finishes.

2. On subsequent coats I use a blend of paste wax and Watco oil. The paste wax gives the oil viscosity sufficient to prevent it from migrating back out of the wood pores and eliminates bleed out. I make the mixture out of Butchers (any paste wax will work) wax and the Watco oil, using an old tin can on a coffee maker hot plate. Stir the mix until the paste wax is dissolved. The hot plate works nicely when applying the finish as well.


----------



## therabidrabbit (Dec 16, 2013)

Is it possible to do what you suggest in step 1, but then instead of wax and watco oil for subsequent coats just continue to apply only the polymerized Tung oil? And if so, will I have to come back and wipe it every couple of hours for every coat? or just the initial sealer? Thanks for the help!


----------



## wormil (Nov 19, 2011)

Here are the directions:

How to Apply Tung Oil
Both forms of tung oil are easy to apply. They are wipe-on, wipe-off finishes. Both penetrate well, sealing the pores of the wood. And both pure and polymerized tung oil build quite quickly. A sealer coat, plus one or two top coats, is usually all you need for a smooth and durable finish.

Pure Tung 
For non-food contact use, always thin with 50% mineral spirits for the first coat. Subsequent coats can be full strength, but must be wiped down after 15 minutes. Always allow ample drying time (48 hours+).

Tung Oil Sealer
Sealer is 20% poly tung and 80% driers. It penetrates well and dries quickly.

High Luster Polymerized Tung Oil
Wipe on, then wipe off after five minutes. Gives a hard, tough finish with a hand-rubbed appearance.

Medium and Low Luster Finishes
For a medium luster finish, add one part Sealer to two parts High Luster. For a low luster finish, add two parts Sealer to one part High Luster.


----------

