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Sodium Clorate -- what is best way to make this Weed Killer

  1. Mar 17, 2015 #1
    Electrolysis of sodium chloride is suppost to make sodium chlorate but its not working for me. I mixed 1 gallon of salt with 5 gallons of hot water then used a 12 volt car battery charger and carbon rods to electrolysis for 7 days. Water volume has gone down and there was a lot of white crystals on the side of the 5 gallon plastic bucket. I stired all the crystals into the water then sprayed and poured the liquid on weeds and grass but not much happened. What am I doing wrong?

    I use to have factory made sodium chlorate it will kill everything even trees, 1 cup in 5 gallons of water would kill anything.

    I have a fence row full of weeds, brush, small trees that all need to be dead. I already spent a ton of money on Weed b Gone, brush killer and 2.4-D. Some weeds have died but most of this stuff is not effected by this type weed killer.
     
    Last edited: Mar 17, 2015
  2. jcsd
  3. Mar 17, 2015 #2
    I'm not sure what your plan is exactly, but if the idea is kill all plant life that is anywhere near you, then concentrated Sodium Hydroxide would (probably) do the job, and some chlorides might kill them even quicker.
    I am glad however that I am not suffering an invasion of life threatening weeds.
     
  4. Mar 17, 2015 #3
    Here is a you tube video where someone uses Electrolysis of sodium chloride to make Sodium hydroxide.
     
  5. Mar 18, 2015 #4

    NascentOxygen

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    Mistake #1 :eek:

    I'm surprised that your carbon rods lasted for days. Wasn't there a surface scum of carbon particles floating everywhere? What level of current (amps) did the cell settle down to, after a few hours?

    The white crystals were probably mostly salt that had come out of solution as the water level fell. There'd be some NaOH in there too.
     
  6. Mar 18, 2015 #5

    Borek

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    My understanding is that's how it is made industrially.

    Compare http://www.google.com/patents/US2511516 (wikipedia gives as a reference for the same process Ullmann's Encyclopedia of Industrial Chemistry). It definitely requires control of a temperature and pH.
     
  7. Mar 19, 2015 #6
    I have not been keeping my solution at 113 degrees F and I have not been mixing salt = sodium chloride at 5 to 1 ratio in water. I will need a heating element and a thermostat. I did not have constant circulation either. Carbon rod did not last long, I wonder if titanium rods or lead rods will work? The information says nothing about voltage and current? I am thinking about using Harbor Freight solar panels they are 17 volts 2.6 amps each panel. I have 9 solar panels. I can get 23.8 amps with all 9 panels in parallel.

    I will not need to percipitate sodium chlorate out of solution I can add more water then spray the liquid right on grass and weeds.
     
  8. Mar 19, 2015 #7
    If the persistent vegetation really is that bad it might be a lot easier to simply hire a digger and rip it all out.
    That way you will also avoid creating a highly toxic area of land that could possibly endanger life other than plants.
     
  9. Mar 19, 2015 #8
    This is what I have to deal with, a yard 3" to 4" full of land scape rock. I live in an HOA neighbor hood. Little Hitler = Gestapo sent me a notice to remove grass and weeds from land scape gravel in 10 days. Arizona plants live in soil that is toxic to most other plants 8ph, 115 degrees F in the summer, and 21 degrees in the winter, no rain for 11 months of the year. If you bring plants from bad East to AZ they will die. Plants here have become accustom to extreme conditions, the same weed killer that works back east will not work in AZ. It takes special weed killer here and sometimes they will not work. I poured kerosene, diesel fuel, gasoline, and used motor oil on some of the hard to kill plants and they still live. I am tired of crawling around in the gravel on my hand and knees pulling plants by hand I have to do it 1 hours every other day to keep up with it. If sodium chlorate kills every plant in my yard even the bushes that is good. I dumped 160 lbs of SALT in the area you see here, so far so good all the plants died. Sodium Chlorate will work many times better than salt, it should only take 1 lb to do the same job. A 40 lbs bag of SALT is $3.85 at Lowes and Home Depot, it is heavy and takes all day to dissolve in water then dump on the yard but I think it will make a great pre emergent I see NO new plants coming up.


    002_zps12yck37m.jpg
     
    Last edited: Mar 19, 2015
  10. Mar 19, 2015 #9
    In regards to your carbon rod issue you might try this.

    Or this.

    Good luck with your weed problem.
     
  11. Mar 22, 2015 #10

    NascentOxygen

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    With all that salt, I take it you have no metal pipes underground there?

    Have you considered a gas flame of some description? I see road workers using a large butane-type burner to heat that white plastic strip they melt onto the road at intersections, etc. Perhaps an oxyacetylene torch, if you have the cylinders on a trolley so it's mobile?
     
  12. Mar 22, 2015 #11
    Flame is slow I tried that and it does not kill roots and it does not stop seeds from growing. I have a large fresnel lens i tried it too. A 5000 degree F spot from the sun will vaporize a weed in 10 to 30 seconds after all the water evaporates from the weed this is slow and weeds are scattered all over the yard. I have to hold the fresnel lens by hand wait for weed to burn up then move to next weed. After looking at that bright spot to burn first weed I am blinded and can not find the another weed for 15 minutes. I tried welding goggles it is too much work and too much time involved. The fresnel lens works great to remove tree stumps it is like a 1" wide laser beam burning its way through the stump at the same speed the sun moves. The lens needs to be moved over 1" every day to burn another slot in the stump. Stump is gone in about month.

    Fresnel3.jpg
     
  13. Mar 22, 2015 #12
    I have quite a bit of experience killing weeds. Trying to make sodium chlorate is a wasted effort. It needs to be done in a factory. You could use sodium hyperchlorite (lye) from a hardware store that will chemically burn the weeds and you if you get it on your skin. Be aware that any those chemicals you apply can wash into places you don't want and kill valuable plants and trees.

    That said, if you have access to a Harbor Freight store, they have a really handy long handled propane torch for killing off weeds and melting snow and such for which no plant has resistance. Once you have killed off your weeds, apply a long acting weed killer that remains in the soil and prevents germination such as Preen. An even better solution is to rake back the gravel, lay down a long lasting weed barrier and put the gravel over it.

    Depending on where you live, some locations have strict limits on what types of chemicals you can use and when. You might want to check your health department before you spread anything.
     
  14. Mar 22, 2015 #13

    NascentOxygen

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    lye is not sodium hypochlorite, lye is sodium hydroxide aka caustic soda and I don't think you'd want that crystallising on your gravel to come into contact with children or pets.
     
  15. Mar 23, 2015 #14
    You're right. Lye is sodium hydroxide. Still, it kills weeds. But, it can burn your skin. A weed torch does the job without poisoning the environment..
     
  16. Mar 26, 2015 #15

    Mark Harder

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    Gary, When you tried the electrolysis, did bubbles of gas form on either electrode? It's possible that H2 gas is created at the anode(?), the negative one. The reason is that the electrons in this electrode reduce the Na+ to Na0, which reacts rapidly with the water to make hydrogen and sodium hydroxide. At the other electrode, where Cl2 is being made the OH- attracted to the positive electrode reacts with the chlorine, yielding hypochlorite (HClO-. Thus, you have made hydrogen and bleach!
     
  17. Mar 26, 2015 #16

    Borek

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    While you are right about the final effect, there is no way of producing metallic sodium in such a setup, water will react first (whether it is just water molecules, or H+, doesn't matter), without the need of sodium intermediate.
     
  18. Mar 26, 2015 #17

    Mark Harder

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    How does that work? Is it a 2 electron reduction of H2O -> H- + OH-? I.e. it's the water that's reduced, not the Na? The hydride and a proton from the solution then recombine to give H2?

    BTW, I did a little research and it looks like the products depend on the NaCl concentration and temperature. But it still looks like a hard way to make Chlorate.
     
  19. Mar 27, 2015 #18

    Borek

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    To be honest I don't know the mechanism, although I do remember reading about it. My bet would be it is not just water molecules reacting, but H+ and OH- - either from added acid/base or just from water autodissociation.
     
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