treating wood with vegetable oil

topic posted Tue, September 19, 2006 - 10:34 PM by  Jason
I'm building some raised beds for growing vegetables and I don't want to use treated lumber. I'm thinking of getting conventional 2x12 doug fir and treating them with some kind of vegetable oil. I figure it won't last forever, but it should give an extra few years. I'm not sure how it would compare to linseed oil in terms of how it would work, but it wouldn't have all the impruties that most linseed oils appear to have. Anybody have any experience or input? Thanks.

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  • Re: treating wood with vegetable oil

    Tue, September 19, 2006 - 11:51 PM

    I have used vegetable oil to treat lumber for years .The one thing i found was that at least for the outside of the beds the wood needed to be treated at least twice a year.

    In Love and Light

    • Re: treating wood with vegetable oil

      Wed, September 20, 2006 - 3:35 PM
      real creosote from distillation of pine roots for turpentine. you could actually make it yourself.
      the still is easily made, just a big retort made from sheet metal. watch out for flammable gases and condensate! creosote is the final tarry fraction of the run. thin it with the turpentine from the main run. brush on.
  • Unsu...

    Re: treating wood with vegetable oil

    Sat, September 23, 2006 - 8:26 PM
    only a few vegetable based oils will truly dry. this drying will provide a harder surface and much more protection. linseed oil is the #1 choice, but if it says boiled, this means metallic drying agents have been added to it. i am sure you can get pure linseed oil, but i don't know where. you could also just press some flaxseed and make your own.

    next best is tung oil and walnut oil. both are sold easily in its pure form. walnut, as you know, you can get at any supermarket. tung oil is easy too, just dont get one labled "tung oil finish" this means it has varnish and other junk. sells a really nice 100% tung oil for a good price.

    another note, when you apply a oil finish, use a brush or an small scrap of clean cotton fabric. let it soak in for 5-10 min, then wipe dry with a clean cloth. let it dry for at least 24 hours, then repeat these steps again, you can put on as many coats as you want this way, more coats will increase the durability of the wood.

    do not use olive oil, canola, corn, soy, crisco, palm, sunflower, cottonseed, rapeseed, peanut, etc, this will never dry and start to rot and get rancid

    another method, you can make a homemade beeswax finish, mix equal parts beeswax, linseed oil, and pure turpentine. make sure all are heated to the same temp. before mixing together, the beeswax needs to be melted to mix. you can also add a little bit of carnauba wax to this, this will harden the wax significantly.

    good link here:

    best of luck, mark
    • Re: treating wood with vegetable oil

      Sun, September 24, 2006 - 9:09 AM
      can this method be used as an interior finish on doug fir windows, as well as for outdoor use?
      I was told to lacquer or stain them but I personally would love to go greener and just oil them a few times a year...
      • Re: treating wood with vegetable oil

        Sun, September 24, 2006 - 9:34 AM
        Any surface which does not have water put on it regularly, indoors, I would prefer to use a brush of beeswax, then buff. It has a lovely finish, odour and is lovely to touch after it has been buffed.

        I have treated cutting boards and wooden buttons with pure linseed oil before, and they take ages to truly dry, and gives off a slightly musty scent.
        • Re: treating wood with vegetable oil

          Wed, September 27, 2006 - 10:42 AM
          thank you mark and jana!
          I just finished an incredible wood-turning/lathe workshop and we treated bowls and plates with a slight rub of mineral oil, then cloth-applied beeswax (some soft mix in a tub?) and a gentle buffing. very pretty and I think non-toxic.

          >as an oil painter, I find linseed to be quite toxic to me, and though it is used as a binder that I cannot avoid in tubes of pigment, I do not use it any more as a painting medium. it makes my eyes turn red and water >weird> so I would not want to use it indoors or even apply it really.
      • Unsu...

        Re: treating wood with vegetable oil

        Mon, September 25, 2006 - 5:42 AM
        sure this can be used indoors as well, it will last much longer indoors. just pay more attention to polishing the oil and use a 0000 grade of steel wool to polish the beeswax finish into the wood
  • Re: treating wood with vegetable oil

    Wed, September 27, 2006 - 10:45 AM
    oh and JASON>> my 2¢
    do you really need wooden-sided beds? I have found that berms or piles are much more garden and gardener-friendly in terms of ease of amending and turning beds, usable square footage (sides of berms are plantable), and also non-harboring of critters who dine on your veggies ~ specifically slugs and snails.
    • Re: treating wood with vegetable oil

      Wed, September 27, 2006 - 7:43 PM
      Berms and piles are friendly if you have a large area. I'm building French intensive beds which are traditionally 14-16" deep. Berms tend to slough off and will get in the gravel paths in between. This location doesn't have snails, and generally slugs avoid exposed areas where they can get eaten, hence the gravel. I've done several beds of this style with untreated doug fir / hemlock and they've worked well, but these clients were wondering about treating the wood, so I thought I'd ask here. I posted a picture of what I'm talking about in the photo album, check it out.
      • Unsu...

        Re: treating wood with vegetable oil

        Thu, September 28, 2006 - 1:37 PM
        that looks really nice! i may use that model in a bed of my own one day! mark
        • Re: treating wood with vegetable oil

          Fri, September 29, 2006 - 7:59 AM
          wow jason beautiful bed! I use french-intensive too, and double dig my unsided beds, but I agree the sides do tend to spill out and soften into the paths, but I'm not such a stickler for clean edges and paths. I know many clients who are tho > so good luck with your quest. many have recommended boiled linseed as a lovely simple treatment for wood that should protect it over the winter.
      • Unsu...

        Re: treating wood with vegetable oil

        Fri, September 29, 2006 - 12:08 PM
        Just a few quick notes...

        In the Pacific NW of the US, the slugs will cross any open expanse from sunset to sunrise.

        I use 1/2" hardware cloth in the bottom of my raised beds to keep out the moles.

        Nice bed. Very nicely done. :)

        My preferred outdoor wood preservative is a mixture of neem oil, bee's wax, carnuba wax (mountainroseherbs), and pure turpentine. It has to be warmed to mix. It should be fully-liquid before applying.

        The turpentine aids penetration of the other products.

        Neem is an all-around great thing for reducing decay organisms and wood-boring insects.

        Bee's wax also has great preservation properties.

        Carnuba wax gives it staying power.
  • Re: treating wood with vegetable oil

    Thu, October 5, 2006 - 9:34 PM
    not to take away from all the other good advice but I have seen great raised beds made from recycled 2x12's (treks like stuff). You make them the same way in the corners but just plastic/rubber/whatever boards. just a thought...