Replies

1. 
   terrylee86 | Feb 16, 2009 01:20am | #1

   Kell,

   My first response is that tung oil is a very poor choice for a dining room table no matter what wood is being used.  You can get an excellent result with a good varnish(not poly, maybe Behlen's Rockhard or P&L) thinned 50 % with mineral sprits a applied with a rag and sanded between coats.  Oil is more of a colorant then a finish.

   Secondly, kiln drying does not change the colors of American Black Walnut, steaming it does.  Most mills steam black walnut to darken the sapwood and it kind of muddles the whole coloration of the board.  I am not sure if unsteamed kilned dried walnut is even available anywhere, but it is not the kiln drying that bleeds the tannic acid out of the boartds, it is the steam.  I have a couple thousand bdft of black walnut that I air dried for a year in my leanto and then had it kiln dried (no steam) and it has the purples and chocolates and blacks of the air dried stuff.  I have some of that as well and I can't tell the difference.

1. 
   Shoemaker1 | Feb 16, 2009 01:52am | #2

   Hey you guys got a couple questions? Were is your wood stored? When are you not home? do you have a big dog or alarm system? Do you have snoopy neighbours?
   Inquiring minds must know?
   Use the varnish tung oil is ok if you want to spend weeks building a finish and touching up once a year.

2. 
   flairwoodworks | Feb 16, 2009 03:28am | #3

   Terry,From my understanding, there are two types of kilns - heating kilns (not sure what the proper name is) and dehumidification kilns. Dehumidification kilns dry wood in the same manner as air drying, only accelerating the process. It is sill slower than heated kilns. The length of time required to dry wood in a dehumidification kiln versus a heated kiln is likely why heat is usually used. The faster wood is dried, the faster it turns into profits.Chris @ http://www.flairwoodwork.spaces.live.com(soon to be http://www.flairwoodworks.com)

    - Success is not the key to happines.  Happiness is the key to success.  If you love what you are doing, you will be successful. - Albert Schweitzer

1. 
   terrylee86 | Feb 16, 2009 05:41pm | #6

   Chris,You are correct. The two major categories of kilns are some type of heat source(solar, electricity or steam tubes like hot water heat) and dehumidification kilns. Both type rely on convection currents (fans) to circulate the air throughout the entire stacks. The big commercial kilns take wood from green to dry in a fairly short period of time depending on the thickness and species. The smaller guys usually air dry lumber for a period of time to get it to a certain moisture content and finish it off with a kiln. The big kilns are the ones that are the most susceptible to drying defects(honeycombing) because they dry the wood too fast sometimes. I have used both types and have not noticed a difference in the finished product. I always air dry my lumber for a year in a leanto behind my barn and then finish it off in a local kiln.

3. 
   SgianDubh | Feb 17, 2009 11:47pm | #10

   As the issue of steaming walnut to darken the sapwood was raised by you terry I am responding to you, but the information discussed in Bill Tindall's short online article on steaming walnut may be of interest to other visitors too.

   The section below is selected from one of my own texts on the subject. The attributed reference to Tindall in the following text is from a version of the article linked to above. Slainte.

   "... Many woodworkers believe the steaming spreads the pigments from the heartwood into the sapwood, but the following quotation argues against this: “The process does not involve diffusing pigment from heartwood to sapwood.” (Tindall, 2007, p 32.) He goes on to describe the process using purpose built steamers after the kilning operation. The boards are close stacked and loaded into the steamer, the doors closed, and the inside of the steamer flooded with hot wet steam.

   As long as the wood rises to the temperature of boiling water, the atmosphere is very wet, and these conditions held for a couple of days the sapwood will turn dark and closely match the heartwood. According to Tindall, when the wood leaves the kiln it looks as if it’s covered in soot, but this planes off to reveal a uniform purple colour throughout. My experience is somewhat different in that more often than not I find the darkened sapwood is only truly dark on the surface and for just a few millimetres (1/8”- 3/16”) below that. By the time I’ve taken two or three passes over a surface planer (jointer in the US) the white sapwood is quite often clearly distinguishable from the dark heartwood.

   This suggests to me one of two possibilities. The first is that the steaming process is not really as effective as wood technologists and wood processors claim. The second option is that it is effective, but only if the process is undertaken properly. If the latter is true which I have not been able to personally test and verify, this suggests that some of the north American wood processors that steam walnut do not properly control or undertake the procedure to get the even colouring.

   Many furniture makers object to the steaming process because of the uniform purple colour that the heartwood, in particular, takes on. They prefer the richer and more varied colours of air dried walnut. Whilst I agree that air dried walnut has these attractive characteristics initially, it’s my experience that within a few months, and at most within a year or two of a piece of walnut furniture going into service, it’s usually almost impossible to tell the difference between air dried and steamed walnut. Within two or three years all walnuts exposed to air and ultra-violet light seem to mature into the soft honey browns we’re used to seeing in furniture that’s seen some service, or indeed, many years or decades of service.

   The driving forces behind the common practice of steaming American black walnut are twofold:

   the main market for the material

   the American grading system

   Sapwood is not a fault in American grading, and the clearest, least knotty planks come from the outside of the tree during the milling into boards. Naturally, these boards from the outside of the tree contain the most sapwood. The biggest buyers of the wood are big furniture manufacturing businesses, either in North America or, increasingly, overseas with China being one example.

   Unlike the small furniture business, or amateur woodworker, the big furniture makers generally cut up larger planks to remove defects, rearrange them and glue them back together to make up required widths, and even lengths. So to these businesses, long, wide and clear boards of walnut aren’t their primary concern. If the small furniture maker requires long, wide and clear walnut planks with all the interesting colours to start with, their only recourse really is to seek out specialist suppliers: this almost certainly means paying a premium over the commercially kilned material."

   Richard Jones Furniture

   Edited 2/17/2009 5:49 pm by SgianDubh

1. 
   terrylee86 | Feb 18, 2009 03:55am | #11

   I was always under the impression that the steaming process caused the tannic acid in the heartwood to leach into the sapwood to darken the blonde wood.  By this leaching process, it caused the heartwood to be a little more bland and lose some of the character of the wood.  Mr. Tillman is right about one thing, if you do not stain walnut it will lighten from UV exposure over time.  My kitchen cabinets are much darker on the inside than on the faces.  Walnut and cherry, over time , end up looking a lot alike because of the UV exposure.

   The walnut I harvested is much darker then the walnut I have purchased from a commercial mill, but I have trees from the same woods that are lighter then others so maybe it is a case by case basis.  I know when I buy 8/4 from a commercial mill( some knucklehead didn't listen to the old sawyer and saw more 8/4) it is much lighter then my air/kiln dried lumber.  I guess I should be happy I am not buying steamed walnut for my projects. 

1. 
   SgianDubh | Feb 18, 2009 11:47am | #13

   terry, here is a link to a thread on another forum you might find useful. Gene Wengert, whose contributions to that discussion I draw your attention to, is a recognised authority on timber technology and his contributions have real weight in any such discussions.

   Once you've had a wee look at that thread there are a few more discussions hosted by Woodweb on the topic of steaming walnut you can search for. Slainte.Richard Jones Furniture

2. 
   JeffHeath | Feb 16, 2009 05:19am | #4

   The GF natural oil is a tung oil/polyurethane mix.  It will provide a little bit of a film finish, but I would not rely on it as a means of protecting the surface of a dining table.  Tables have a tendency to get heavy use, with quite a bit of abrasasives from around the house finding their way to the tabletop.  That finish alone will not provide much of an adequate defense against scratches, etc.....

   There are many better choices, some of them already given in this thread.  Without knowing whether or not you have spraying capabilities, it's hard to give you good answers.  I use a water based film finish known as Crystalac Premium for my table tops, and I love it.  It's a spray-only application, though.

   More info for more help.

   BTW, I only use air dried walnut when I can help it for the same reasons.

   Jeff

3. 
   SteveSchoene | Feb 16, 2009 05:31am | #5

   Seal A Cell is an oil/varnish mix, and while it will provide a more protective surface than the linseed oil finish used by Moser, it still doesn't build a film on the surface that provides a great deal of protection.  Most people feel dining tables need more protection, but that is a very subjective thing and depends on how you will use and care for it, and how you feel about small stains and marks.  If you use the oil/varnish finish filler will end up being a bit more noticeable than if it is under a film finish. 

   I've never been very happy with mixing saw dust with epoxy or finish, etc.    .  Commercial wood fillers work about as well and offer you a wider range of colors.  Walnut is a bit of a challenge, since you want to fill cracks or holes but not the pores around them unless you fill all the pores.  You will have to mask the surrounding areas carefully to keep filler where you want it.  Even so, when you use fillers with a oil/varnish "in the wood" finish, the surface texture and sheen  of fillers is likely to be more obvious.  Film finishes do a better job of making the fillers look less obvious.  For a film finish a good non-polyurethane varnish works well.  If you don't plan to fill the pores, then apply the finish thinned and keep the total film thin to give a cleaner look around the pores. 

4. 
   HowardAcheson | Feb 16, 2009 07:59pm | #7

   David Marks did not use a real tung oil on his TV projects. He used General Finishes Arm R Seal which is a thinned wiping urethane varnish containing no real tung oil at all. If you go to his web site, he explains what finish he really used. I have never heard a satisfactory explanation why he persisted in calling his finish "tung oil". He certainly knew the difference.

   That said, you can easily make your own thinned wiping varnish. Just mix a 50/50 ratio of your favorite varnish or poly varnish with mineral spirits and you will have a better and more durable finish than that used on his TV show. Of course, using a real non-poly varnish will improve the clarity of the finish.

   Howie.........
1. 
   Kell | Feb 17, 2009 01:25am | #8

   Howie,

   Thanks for the reply.  I know that it isn't Tung Oil but I couldn't remember the full name of the stuff.  It is the GF stuff that he uses which I'm applying here, too.  I've used it on our kitchen counter tops and my wife loves the way it looks and feels so that's what is going on the table top as well.

   Any fillers come to mind?  I have never used anything but grain filler and these spots are way bigger than pores to be filled.  That's why I was considering the sawdust and epoxy method.  I will probably test it first and make sure the SWMBO will buy the result anyway.

   Kell

5. 
   Curtis | Feb 17, 2009 01:40am | #9

   Hello

   I agree with you Air dried Walnut's colors can be breathtaking.

   What I've always done on making my own wood filler, is to use the saw dust from the wood being filled, and to use what ever sealer that I'm using as the bonding agent with the dust to make my filler. I find this method works well for worm holes and small  knots. But for cracks? (it all depends.) 

   Why not just leave small cracks alone,After all they are part of the woods beauty, You always use them as part of the detail.

   I feel that Every job should be judged on a case by case basis. I find sometimes its easier to just cut the crack out and re-glue the wood back together, instead of doing a repair after the fact.

    In the worst case, you could always use a Dutch-man to hide the crack?

   Good luck .

   C.A.G.
6. 
   stantheman | Feb 18, 2009 04:11am | #12

   re: filling wormholes and cracks

   I've never had much luck with mixing sawdust with epoxy.  For me, to get the wood content high enough to make the color match, the mixture gets too thick and unworkable to get into cracks.  I have been using superglue (slow curing gel) for cracks - fill the crack with glue, then sprinkle the sawdust over it, pack it in and saturate.  For small holes, I prefer using burn sticks (they come in walnut), or drops of thick garnet shellac until they are full, sand to even with surface.  Bigger holes, almost nothing is invisible, but prefer the dutchman fix.  Just my amateur experience. 

1. 
   Kell | Feb 19, 2009 01:39am | #14

   That's an excellent suggestion Stan, on the superglue gel. I'll give that one a try to. Much obliged!Kell