Results 1 to 9 of 9

Thread: Does Formby's Tung Oil Finish darken wood?

  1. #1

    Does Formby's Tung Oil Finish darken wood?

    I want to refinish a rustic dining table, and want to avoid a poly finish; instead, I want an "in-the-wood" finish. But I really want to avoid darkening the wood. I know that pure tung oil will darken less than boiled linseed oil, but it takes a long time to dry. Because it's a dining table, and some protection wouldn't be bad, I am leaning toward some oil/varnish blend. I hesitate between Minwax tung oil finish and Formby's tung old finish.

    I understand that Minwax TOF doesn't have any TO; instead it has BLO. On the other hand, Formby's does state that it has TO. The Formby's MDSD suggest that it is a modyfied soya tung alkyd resin finish. I read somewhere that soya oils darken the least.
    http://www.hardwarestore.com/media/msds/260315.pdf

    Therefore, am I correct to conclude that Formby's TO, even though it's not pure TO, does have some TO and soya oil and therefore will not darken wood as much as Minwax TO finish or BLO?

    If Formby's is the way to go given my goals (some protection, avoid darkening), is there any suggestion as to how to proceed? I read somewhere that someone has the first coat 75% mineral spirit/25% Formby's, then 50-50, then 25-50, and ends with a fourth coat of 100% Formby's...

    Thanks
    Last edited by Carlos Arteta; 05-16-2009 at 2:44 PM.

  2. #2
    Join Date
    Jul 2004
    Location
    Southern Kentucky
    Posts
    2,218
    If you put oil on wood it will change the color----that's just they way it works-----some finishs will have more of a affect than others.
    I would keep it easy----Danish Oil---you can thin it---apply several coats and buff if you want some gloss.
    ---I may be broke---but we have plenty of wood---

  3. #3
    Join Date
    Oct 2007
    Location
    Fort Worth, TX
    Posts
    1,304
    I did 4 coats of formbys on a small box I made for my wife that had walnut/curly maple. It kept the maple about as clean and crisp as you could expect without yellowing/darkening it. I was happy with the finish, as I wanted the maple to retain its clean color.

    I can't say much about it long term, so maybe someone else will chime in on that aspect.
    Grady - "Thelma, we found Dean's finger"
    Thelma - "Where is the rest of him?!"

  4. #4
    Thanks for the replies. I am increasingly leaning toward Formby's.

    Another question: if I were to go for a cerused/plicked effect, do you think that Formby's, being an oil and (I guess) unavoidably leading to some darkening, will "ruin" the cerused effect? For example, Minwax pickled oak stain states that it should topcoat with water-borne poly, not oil-based poly. I will definitely not use poly -- I will use an "on-the wood" finish.

    Thanks

    (By the way, does getting a cerused effect is as simple as using a pickling oil-based stain? Or is it better to use some sort of "wax"?)

  5. #5
    Join Date
    Mar 2003
    Location
    Southport, NC
    Posts
    2,974
    >> On the other hand, Formby's does state that it has TO. The Formby's MDSD suggest that it is a modyfied soya tung alkyd resin finish. I read somewhere that soya oils darken the least.

    Formby's "Tung Oil Finish" is a alkyd and soya/tung oil varnish pure and simple. If you look closely at the label you will find that Formby's even calls it a varnish.

    Varnish is made by mixing a resin (in this case, alkyd) and a drying oil (in this case a mixture of soya and tung oil). The mixture is then heated until the resin and oils combine into a new compound called varnish. Once it becomes varnish, it's no longer identifiable as tung oil. The closest Formby's Tung Oil Finish comes to being or containing tung oil is in it's name.

    That said, because it it made with alkyd resin and soya and tung oil, it will be a minimally amber color finish. But, it will have some amber color and I would not use it over any white or pickled finish.

    Minwax is correct, use a waterborne clear acrylic finish. Waterborne acrylics dry water clear and will not yellow the white coloring in the pickling stain.
    Howie.........

  6. #6
    Thanks for the reply. Because Minwax TO is composed of who-knows-what (likely linseed oil), while Formby TO is soya/TO, it sounds like Formby's TO is the way to go to minimize darkening. I also gather that Minwax TO is oil/varnish while Formby's is wiping varnish, but that both will result in a similar "on-the-wood" look, right?

    If I decide to not do the pickling, then I will use Formby. If, however, I want to do the pickling, and thus I need to use water-borne products, is there any water-borne product that gives an "on the wood" look, that is, that closely resembles an oil finish? If there something like water-borne wiping "varnish"? I don't want to have the "plastic" look of poly (in this case, water-borne poly).

    Thanks

  7. #7
    Join Date
    Mar 2003
    Location
    Southport, NC
    Posts
    2,974
    Carlos, I'm going to somewhat go back to the basics here to be sure there is an understanding of what I am saying. In apolagize in advance, if is go over stuff you already know.

    First, an oil based pigment stain like Minwax Wood Finish contains a small amount of resin (varnish) to hold the pigments onto the wood surface. This resin also "seals" the surface of the wood almost totally preventing the absorption of any subsequent stain or clear coat. So, if you plan to use a "pickeling" stain, you will also end up sealing the wood. Unless I missed it, I didn't see what species of wood you are using. Some woods accept a "pickling" color of stain better than others.

    If you want to end up with an "in the wood" finish, your staining will have greatly impeded the absorption of any in the wood finish link Danish Oil, Tung Oil Finish or oil/varnish. So that may be out. A film finish like Formby's or any other thinned wiping varnish does not need to penetrate so works very well over an oil based stain. If only one or two light coats are applied, a thinned wiping varnish can look quite a bit like an oil/varnish finish. However, for a dining table, you will want to have some level of protection I would think. A protective film would require 5-6 coats of Formby's or any other thinned wiping varnish. If you use the pickling stain any oil based varnish--including Formby's--may not work. Because it is oil based, it will have an amber tint. Sure, because soya and tung oil are light colored oils, the amber will be less than a linseed oil based finish, but it will still be somewhat amber and it will be noticeable on a "whitish" stain.

    So, what to do. I recommend you consider using a waterborne clear acrylic poly. It will be water clear when dry. If you brush on 2-3 coats, it will not build appreciably and will not have the plastic look of a thick coat. BTW, it's not the poly in poly varnish that creates the plastic look, it's the thickness of the finish.

    The final piece of advice is to test out a number of finishing schedules on some scrap to see how they look and to learn how to use them. Don't even think of applying a finish to your table until you have worked out all the details on your samples.

    To summerize, if you end up using an oil based pickle stain, use a waterborne clear finish. If you do not use a stain, you can use an in the wood oil/varnish finish like Watco Danish Oil or Minwax Tung Oil Finish. You can make your own by mixing two parts Formby's to one part pure, real tung oil, and one part mineral spirits. Apply like any other oil/varnish. Wipe or brush on, let set for 15-30 minutes and wipe off all the excess. Do it again the next day and let it dry 3-4 days. Or, you can apply 5-6 coats of the Formby's for the most durable and protective finish.
    Howie.........

  8. #8
    Thanks for your reply, Howard. I'll test the different options before proceeding.

    One last question. I expect that this (very rustic) slab table will "age" with the family, getting daily use with no coasters, placemats, or similar protection. Ideally, the finish I am looking into would allow little marks and dings and rings and the like to add to the look and the character of the table, not a finish for which marks and rings are a problem. That is why I am hesitant about the wb poly (e.g. white rings will likely be a problem, not a plus, due to the film... but I guess Formby will have a similar problem...), even if the coat is thin...

    I read an article about just oil and wax. The article used BLO, but states that TO is better to avoid darkening. But I cannot easily get 100% tung oil in the timeframe I have.

    In short, following your advice, if I want the look that I mentioned two paragraphs above, I am better of with oil/varnish, because the pickling+water base poly will not age nicely with dings and marks. Is this correct? In other words, it is difficult to have both a pickling effect and an "in the wood" effect that will age nicely, right?

    And lastly, allow me to do a wild extrapolation of your description of what an oil stain is, which perhaps would let me surmount the difficulty expressed in the lst paragraph. Oil-based stain (e.g. winxax) penetrates, stains, and seals, and it does have some resin (varnish) on it. Can I then understand the minwax pickling stain as some sort of "white pigmented oil/varnish combination"? I mean: the stuff penetrates (like oil) and seals (like diluted varnish). I am asking that because it may be an alternative: rather than an oil-and-wax finish that will allow the table to age with character, I perhaps could use the pickling stain and *not use any topcoat* but simply clear wax. That way, I have my "on-the-wood" finish that will age with the dings and marks (i.e. not topcoated with thin waterbased poly), and with the subtle and repareable protection of the wax. Is this right?

    Thanks

    Thanks
    Last edited by Carlos Arteta; 05-17-2009 at 5:17 PM.

  9. #9
    Join Date
    Mar 2003
    Location
    Southport, NC
    Posts
    2,974
    If you are not going to use placemats and/or coasters, no finish is going to maintain its appearence for very long. An oil/varnish will be particularly short lived as it has relatively little water and water vapor resistance.

    You need to understand that you can not have durable, long lasting protection without a substantial thickness of a film finish. A waterborne acrylic would be your best choice if you want to have a water clear finish. A good interior oil based varnish would be a somewhat better choice but you will have to put up with a yellow cast. Take your choice. Finishes are always a compromise.

    Whatever you do, keep hot and cold items off the finish for at least 4 weeks, 8 would be better. It takes that long for waterborne and film finish to become completely hard and develop full protection.

    Finally, there is nothing special about the "pickling" color stain. It's identical to the other Minwax stains in that it contains varnish, linseed oil, thinner and a colored pigment. Even though it contains a varnish, the varnish component is minimal and not enough to offer any long term or even short term protection. Wax promotes white marks from heat and color and offers no moisture protection.
    Howie.........

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •