Replies

1. 
   SteveSchoene | Aug 06, 2009 08:57pm | #1

   The answer is that one can't really know.  Some driers have an impact on tung oil, others almost none, so unless you know which driers are in a particular brand of tung oil, and which are effective (I don't) I wouldn't mess.  And, without lots of experimentation, how much drier is too much, and likely to cause problems with the durability of the oil?  BLO is only slightly darker, dries faster, requires fewer coats to obtain an even sheen, is cheaper, and doesn't have the risk of turning "frosty" in appearance if one hasn't held their mouth right during the application process.  Both oils have only minisule protective qualities.   

   Secondly, 24 hours is generally a bit too short a time between coats of pure tung oil,  typically 3 full days, and a little sanding, is needed between coats.   Being sure to have wiped off all excess oil thoroughly after application. 

    

1. 
   Jammersix | Aug 07, 2009 12:54am | #2

   Thanks for the answer, Steve.Thinking back, that explains a couple "mysteries"-- I guess I've been lucky with Tung Oil.I didn't realize that there could be differences between brands in "100% Tung Oil".

1. 
   SteveSchoene | Aug 07, 2009 05:34am | #5

   I don't know that there is that much difference between brands of products labeled just 100% tung oil or pure tung oil.  But there certainly are differences among brands of Japan drier. 

   Differences also arise if the tung oil is has been polymerized--and the degree to which this has been done can make big differences. 

   This of course is quite different between differences among brands of product labled Tung Oil finish.  The noun in that name is Finish, with tung oil just an adjective that is only a manufacturers description of a finish that calls tung oil to mind, in the view of his marketing department.  It promises nothing.   

   Personally, I would never use a pure oil of any variety as a finish.  For the oiled finish look in general I would always opt for a mix of oil and varnish, being sure to wipe off all excess much as I would with oil.  Very hard to tell the difference in appearance between oil/varnish mix and pure oil, but the oil/varnish is longer lasting and more protective.  It is also just as easy to renew when the finish crystalizes and becomes dry looking. 

1. 
   Jammersix | Aug 07, 2009 08:16am | #6

   That's interesting, Steve.Is protection your only objection to pure oil?

1. 
   SteveSchoene | Aug 07, 2009 12:24pm | #7

   That's pretty much it.  If they look the same, but one protects a bit better then that's a plus in my book.  Now, close side by side comparisons might appear a bit different so you do have to decide if the difference matters, or whether differences can be changed by changing the spacific materials in the oil/varnish mix. 

   The world certainly won't end if you use pure oils.  Though you might think it so if a tung oil project gets a frosty look in patches--it's not a common problem I don't think, but can happen.  And, the only cure is stripping off and starting over. 

   And, of course, "protection" isn't always a very important criteria--it depends on the object and how it is used. 

2. 
   Jammersix | Aug 08, 2009 01:23am | #8

   Protection isn't very high on the list-- the subject is pistol grips.Small, wooden slabs on the sides of semi-automatic pistols.There are basically three criteria for the finish.One is mine, two are the industry. Mine is simplicity. My favorite thing about tung oil is that it's extremely simple. No mixing, no measuring, no fussing, very forgiving. Slop it on, wait half an hour, wipe it off, move on. No three parts of this and two parts of that. No special gear. No respirator. No spraying. No artwork. No careful brushing.Even adding Japan dryer cuts into that, and that's why I've resisted it all these years.The first requirement from the industry is tradition. Oil is what, apparently, has always been used on pistol grips, and this IS, by definition, an extremely conservative group of people I'm trying to sell to.The other requirement is a weird one. If you tell a customer that it's a pure oil finish, and it's very easy to repair, all they have to do is add a little oil, they'll be happy. They'll throw the grips on their weapon, and forget about it. They won't refinish them, they'll come back and buy new grips. (That said, I suppose I never hear from the customers who DO refinish their grips...)Gun grips continue to generate the highest revenue per board foot, so it's probably where I'm going to stay. :)No use lifting a bigger piece of lumber than you have to...I've been reading since I started this thread-- I notice that at least one manufacturer of tung oil recommends 24 hours between coats. Could be where I got the idea, I suppose.

   Edited 8/7/2009 6:25 pm by Jammersix

2. 
   forestgirl | Aug 07, 2009 01:10am | #3

   Jammer, I had a wrestling match with tung oil a few years ago, and did some research online about driers.  Unfortunately, I didn't bookmark, or at least not effectively, but memory tells me that, in general "Japan Drier" is a loose term for metallic driers that can have different ingredients in different proportions.  There's no exact recipe for contents or precise use.

   I also gathered, from one article by an oft-cited finishing expert (wasn't Jeff, but not sure who it was) that cobalt was the primary ingredient that affects the drying properties of tung oil [he actually said it only responds to cobalt].  It's quite possible that whatever Japan drier you buy might not even have cobalt in it.  Anywho, to continue, off I went to the art store to get some cobalt drier.  I used it, just a tiny little bit, and it seemed to help but there was discussion here as to whether it really made any difference.

   If I learned nothing else, I learned that finishing with tung oil requires patience, patience, patience, and trying to rush the process (I was under a deadline, and things were not going well) only comes back to bite.  With the weather cooling as it has this week, you'll want to be sure your shop space is warmed up before finishing.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 
   
1. 
   Jammersix | Aug 07, 2009 03:23am | #4

   When my assistant Bambi gets in in the morning, she sets the temperature in the shop, and I think that when Lola measures the humidity, they adjust it again. At least, that's what Jade has been telling me. So when I get in, the coffee is fresh, the shop is clean and ready, and the cut list is being cut.But then I wake up, reality sets in, and I go down to MY shop to work...My shop is in the basement, it's part of the house, and doesn't usually have big swings in temperature. Lately, it's been too hot down there.I can control the heat a lot easier than I can control the humidity. I can crack the garage door, and turn on the ventilation fan, which puts a fair breeze through the whole place.Last week, though, it was hotter outside than in, and I was sucking hot air in, so I didn't even do that...It's interesting what people have had to say about Tung oil. I don't doubt any of you, I've never used anything but pure Tung oil, and up until I posted this thread, I've only used 24 hour cycles. That said, I HAVE seen some of the fogging that Steve mentioned in the past, and it pleases me to have that explained. Experience only goes so far, particularly when you're just repeating mistakes.I'm a fairly patient man, except where fools are concerned, and once a pipeline is full, I don't have a problem waiting for stuff to come out the other end of it.I like Tung oil. I always have. It's the only finish that I actually like the smell of, so maybe what I'll do is simply increase the diameter and length of my pipeline, and start having stuff spend a full 72 hours between coats.Which means I'm going to need a bunch more drying racks...