tung over danish oil?

The first thing to do is to test it on a scrap piece of wood.

I was unable to get the product information for Watco Danish oil on the internet. Each company have their own recipe. Some use a mixture of polyurethane, urethane, linseed, Tung oil and other stuff. Conversely manufacturer of Tung oil also use their own blend. Minwax Tung oil is almost like Danish oil. They blend a percentage of Tung oil with a varnish base and other ingredients. I have use Watco Danish oil (walnut) on solid maple wood book cases. After ten years of looking at the walnut finish I got tired of it. I then refinished the book cases and applied Clear natural Danish oil finish from Deft a mixture of Tung oil and urethane. I applied a second coat using Tung oil from Circa 1850. Which is a mixture of 65 % Tung oil with 35% solvent as a dryer. Tung oil will darken wood a little. I use it over pine to give it a honey look before applying clear waterborne varnish.

You sacrifice a bit of clarity for "minimizing darkening." Not to mention that a lot of people claim walnut lightens as it ages in. Tung polymerizes into fairly large molecular weight strings, scattering light a bit. Sort of "satin."

Other than that, you can consider you've put on a coat of sealer. Think the recipe for Watco has returned to phenolic resin in a soy or linseed oil base from the interim alkyd. Not a lot of resin, so should work.

Watco is a mix of drying oil and varnish resins, it is probably compatible with having the tung oil applied over but as far as shading, I don't think you'll see any difference. Why not just continue with the Watco? The neutral shade will make it no darker than the tung oil would, but it will be a more protective finish than tung oil, and you'll have no nagging worries about compatibility.

Correction, (yes this is a pet peeve of mine) That is Minwax "Tung Oil Finish", right? The word "Finish" is what clues one in that it is not just tung oil. I don't know of any product labeled "Tung Oil" that is anything but pure tung oil.

Danish Oil is usually just thinned linseed oil with driers and colorants and maybe some resin or other oils. Any other oil finish should go over it just fine. AFAIK there are no oil finishes that have ingredients that make them incompatible with other oil finishes.

Some people even put oil over shellac. I haven't seen what that looks like, but they tell me it works fine.

(I know Mr/Ms Marierd was informing, not criticizing, but IMHO those who DO criticize manufacturers for selling tung oil finishes that are not 100% pure tung oil are as justified as if they were criticizing a latex paint manufacturer for selling latex paint that is not 100% latex.)

Larry,

The darkening I'm referring to occurs over time (months/years). It's my understanding that this is less of a problem with tung oil--but I could be mistaken about that as I haven't used tung oil before. The walnut I used for this piece has some beautiful but subtle color variations that I want to bring out, or at least avoid masking. I suppose I could try the Watco on a test piece of the Walnut--but I still have to wonder what it will do over time.

Sid

The following is offer for your perusal:

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: snipped-for-privacy@nb.sympatico.ca wrote: :> The first thing to do is to test it on a scrap piece of wood. :>

:> I was unable to get the product information for Watco Danish oil on the :> internet. :> Each company have their own recipe. Some use a mixture of polyurethane, :> urethane, linseed, Tung oil and other stuff. :> Conversely manufacturer of Tung oil also use their own blend. Minwax Tung :> oil is almost like Danish oil.

: Correction, (yes this is a pet peeve of mine) That : is Minwax "Tung Oil Finish", right? The word "Finish" : is what clues one in that it is not just tung oil.

Worse than that, "Tung Oil Finish" may contain zero tung oil. If you want tung oil, get a can labeled 'tung oil'.

I don't : know of any product labeled "Tung Oil" that is anything : but pure tung oil.

Right. And as a suggestion, I've found that it builds better using real turpentine, not mineral spirits, as a thinner.

: what that looks like, but they tell me it works fine.

: (I know Mr/Ms Marierd was informing, not criticizing, : but IMHO those who DO criticize manufacturers for : selling tung oil finishes that are not 100% pure tung oil : are as justified as if they were criticizing a latex paint : manufacturer for selling latex paint that is not 100% : latex.)

Well, the conventional meaning of "latex paint" as "contains latex" is fine with me. What I find objectionable is 'tung oil finish' labelled as such when it contains no tung oil -- it's like 'latex paint' that was, say, oil-based with no latex at all.

There's notnign wrong with the finishes that I've used that are 'tung oil finishes' -- I just wish they'd call them something else.

-- Andy Barss

Tung oil may darken some timbers a little, I can vouch that it will darken others A LOT. I used it on some (unknown) eucalyptus secies that I made a hearth surround out of and it took the wood from light orange to dark dark purply tinged brown in a few days.

I have used it on other woods and hardly noticed any change in colour at all.

Testing is essential, i.m.o.

-Peter

Well, what I like to do is fully immerse everything in Walnut oil for two days because it's food-safe, then proceed to 2 coats of danish oil because it makes the grain pop, 1 coat of tung oil because it is "traditional", 3 coats of shellac (french polished, of course) to make it shiny, then an oil-based poly for outdoor protection, 3 or 4 coats of water-based poly to cover up the outgassing from the oil poly, and then finish it off with a good primer and a coat of enamel paint, to make sure that my careful finishing is protected. After that, I shine up the paint with paste wax.

That'll teach that damn wood to mess with my extensive finish collection!!!!

Seriously man, just pick a finish for the project and be happy with it. Why go through all the headache of worrying about the compatability of different products that do the same thing? Finish it off with the Watco and enjoy your bookcase. If you don't like it, strip it off and start over.

Always a bad idea for finishing.

Sounds like a recipe for alligatoring in a couple of years.

I read that a lot.

Do you have a specific example?

I suspect it's one of Bob Flexner's straw men.

Just for your reading, you may want to have a look at:

Sid,

I have used tung oil over Watco many times. It works fine.

Rudy