Tung Oil drying time

[jaguiler]

Hello - I see by many posts and info on the Internets that Tung Oil (100%) takes a long time to dry.  But there is no specific time - 

 

1. How many coats does kayak frame take ?

2. What do you think the approx (given differences in temp and humidity) drying time for Tung oil is for a kayak frame ?

 

Thank you in advance

 

John

 

PS - My choice as of now is BLO by Kleen - from Home Depot.  I do like all the positive things I have been reading about Tung oil - but the downside is the drying time.  I want to finish the kayaks for my kids ASAP - before summer is gone.

[PAR]

It's all about temperature and humidity, so times are all over the place. Expect a few days in good conditions and a week or more in lousy. I never use tung (or any oil) straight, but the last coats will always have a small percentage of Japan Drier, to help speed things up and harden the end result.

[jaguiler]

How many coats ?

How many coats of BLO would you suggest ?

[PAR]

Boiled linseed oil isn't the same as tung, though can be used in the same way. BLO tends to darken dramatically with UV exposure, turning grayish black eventually. I've stopped using BLO for this reason and also because tung seems to keep the wood "oiled" longer.

 

The number of coats depends on what it's going on (species) and how you apply it. The simple answer is a lot. The first few coats (3 - 4) will be cut 50%, some use a heavier cut. This soaks in quickly, but still needs time to dry. The usual application is to soak the wood, until it can't take any more, then wait. When this seems to have dried (it's not) soak it some more. You do this repeatedly, until it can't absorb anymore. The first few soakings will be a 50% cut, with subsequent coats having progressively less of a cut (60, 70, 80, 90%, etc.). Once I get to 90% oil, the Japan Drier goes in for the final coats.

 

In the glory days of sail, an oil coating on fresh, raw wood would be 1 coat per hour, for the first day, 1 coat a day for the first week and one coat a month until you where tired of the oil and stepped up to varnish. With Japan  Drier, you can skip the once a month thing, but it only buys you a few months down here in the tropics, maybe 6 up in the great white north, before another application is required. This is one reason I don't recommend oil finishes to anyone. It does require a level of maintenance coats, that most aren't willing to do. The only place I think oil coatings are worth the bother is cockpit grates or slats.

[jaguiler]

But reading here - the best coating on these frames is the oil.  So with that time schedule - Tung may be out - and BLO in, regardless of the darkening - I can use polyurethane on the visible wood in the cockpit to protect from UV.

 

What are other frame coating options ?

[Hirilonde]

PAR's reply about oil is quite accurate from a historic perspective and good advice for exposed wood in/on a wooden boat that is left in the water or at least outdoors.  The degree of protection he is describing is way over kill for a kayak frame that is stored indoors and  exposed only with use.  I put 2 coats on my frames, let it dry a couple days and get on with the skinning.  I have used both BLO and Tung oil.  Both are satisfactory.  For paddles I like Tung oil as it is harder and feels better IMO.

[jaguiler]

Thanks Hirilonde - this was my logic and what I suspected - thanks for the info - and confirmation.