citric acid to remove radiator rust

Discussion in 'Car Talk' started by upontheriversky, Oct 4, 2011.

  1. upontheriversky

    upontheriversky Senior Member
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    hi,

    anyone encountered or used this method before?

    ive read on forums where people use citric acid with water, warm up the engine and run for 45 minutes and drain the solution and it works

    people had success removing rust with this method but none guarantees that it wont hurt the seals, waterpump etc

    comment?
     

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  2. arturo

    arturo nooB
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    Wat will it do the the hoses and engine block? not all blocks are made from same materials...a little risky if you ask me

    i just send to a credible cleaner who has the pump type which pumps soapy water thru the whole cooling system first to remove the oxidation then clean water a 2nd round to clean the soapy water...less than rm100 n peace of mind.
     
  3. Veloc

    Veloc Senior Member
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    Let's use science...

    Acid makes oxidation faster. Not cleanses it. It can be used to dissolve away the top layer of rust. However, once dissolved away, the acid immediately hit the fresh layer of metal therefore slightly oxidising it almost immediately.
     
  4. risyia

    risyia Senior Member
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    I think using baking soda is a safer option than using citric acid. U can google the net about people using baking soda to clean the radiator core.
     
  5. eohl79

    eohl79 5 Year | Silver

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    Wiki says that citric acid is used in the industry to remove rust from metal. Also works with hard water (minerals in water). Would work I guess for the radiator to remove rust and scale. But not as a solution to the rust problem.

    I would change the radiator to an aluminum type. Don't want to take the risk of sudden water leakage or clogging. Also you won't be sure that the rust will be totally removed as you can't see within. Rust will come back and haunt you again.
     
  6. upontheriversky

    upontheriversky Senior Member
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    thanks, i've seen people using baking soda with success too, will look into it

    i've recently changed to alu rad, there are rusts at engine block side so i thought i would remove rust and scale from whole system and starts fresh with a cleaned cooling system.

    i dont think baking soda is corrosive that it would harm seals and waterpump right?
     
  7. eohl79

    eohl79 5 Year | Silver

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    Honestly never tried baking soda. Just make sure there are no deposits or minerals in the water. Be sure to do a thorough flush. If not mistaken small particles is bad for Alu radiator. Use distilled water and a good coolant.

    ---------- Post added at 04:12 PM ---------- 6 hour anti-bump limit - Previous post was at 02:26 PM ----------

    Bro not advisable to use baking soda on aluminum. It will attack it. Go Google it.
     
  8. upontheriversky

    upontheriversky Senior Member
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    i could not sit tight and not trying it for myself so i did use 50/50 vinegar solution into the radiator and ran the engine for 2 days.

    before i decided, i went through deep research and i found out about this:

    1) The acetic acid in vinegar reacts with the rust (iron oxide) to form a water soluble salt. (ferric acetate)

    Fe(OH)3 + 3CH3CO2H -> Fe(CH3CO2)3 + 3H2O

    meaning if i were to test the result, i just take a dip in the water solution and taste it, if it tastes salty means rusts were reacted with vinegar and deformed.

    2) if you have rust, then vinegar that contains acetic acids, will dissolve your rust

    3) if the steel or iron doesn't have rust, then vinegar can rust the steel or iron 'cause it contains acid.

    this is the water and coolant solution drained before the process begins:
    [​IMG]

    2 days after run with vinegar resulted in a clear water solution when i drained them today, no brownish colour as i would have expected. however when i took off radiator in and out hose, i can see that rust is almost completely gone, im not sure about further inside but that was good enough, if rust is gone near the block inlet/outlet, further inside should be the same as well. i took a dip and taste it and it was indeed salty and smell sourly stinks haha

    i flushed it again with running water and after that decided to add baking soda for further trial and also to neutralize any acidic compound left. This time I only ran the engine for half an hour and drained it. To my surprise this is the color of the water solution when i drained them:
    [​IMG]

    i took off the hoses again and found out it was cleaned and i can see bare metal at the block outlet and inlet but no rough surfaces as if it has been corroded in any way. i was happy :). I flushed everything for 15minutes of running water and refill with coolant like normal flushing.

    i guess the trial is halfway successful. i will test drive for couple of weeks to see if any leaks or bad stuff happening. i drove around for 15 minutes and temperature was stable and no sign of leaks whatsoever yet, i will do the updates after a week of driving but i have a feeling that it was successful.

    reason why i felt it was safe to do so is, vinegar and baking soda are mild acid and alkali chemical and they are also edible, so if its gentle on our stomach, it should not do any more harm on the radiator even at high temperature. my uncle used vinegar to dissolve rust on rusted heating coil in the water heater, he put vinegar in and boil it for 15minutes and it was fine
     
    #8 upontheriversky, Oct 11, 2011
    Last edited: Oct 11, 2011
  9. blitzs360

    blitzs360 15 Year | Platinum

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    yep vinegar is completely safe, i also use it to remove rust from my rusty car parts.

    just let it soak in a container filled with vinegar overnight and voila looks like new the next morning
     
  10. DanzEterna

    DanzEterna Moderator
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    let wait for izso's diy on how to clean/flush radiator system....
     
  11. D7zul

    D7zul Senior Member
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  12. eohl79

    eohl79 5 Year | Silver

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    I am not a chemist and don't know too much on chemical reactions but has some concerns based on what I know and read. I was worried that since the radiator is aluminum and engine block iron. I didn't like the combination and usage of baking soda as aluminum is more reactive than iron (Fe). So if the iron has rusted (iron oxide), the aluminum may act as a sacrificial material to remove oxide from the iron.

    1. Reminds me of the high temperature pyrotechnic thermite experiment which I did back in secondary school chemistry lessons - aluminum shavings mixed together with iron oxide (rust) and placed in the center of a pot with sand. Magnesium strip fuse was used to ignite the materials together which generates a lot of heat and a some high intensity flames. This resulted in the sand melting and turning into glass. What is left from the reaction is aluminum oxide and iron (Fe).
    2. To safely bring back the luster to silver, an aluminum sheet is used together with baking soda solution. Silver loses its luster through sulfur in the air rather than oxidizing. Here aluminum is also used as the sacrificial material.

    If we have a chemist here... please shed some light here.
     
  13. wafuk

    wafuk 5 Year | Silver

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    i see good discussion in regards to material content and chemical reactions. can anyone shed some light on the usage of paracetamol @ panadol to avoid rust in radiators? any significance or possible good reaction chemically to panadol contents? an interesting comment is that it cancels out chlorine or limestone content in our waters?

    thnx.
     
  14. eohl79

    eohl79 5 Year | Silver

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    :argh: Wah! :hmmmm2: Headache! :dontknow:
    I would go with a good bottle of radiator coolant/anti rust instead.
     
  15. upontheriversky

    upontheriversky Senior Member
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    u have a good point, i didn think of that before proceeding, now im a bit scared..
     
  16. Izso

    Izso Boooooossst
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    You know guys, I admire the chemistry and the work done here in testing and all but the simple thing is, as long as you maintain the car 100%, it'll work 100%.

    Whether there's rust or not in the block, only determines how much more often you need to flush the cooling system. Let's take uponriversky's car as an example. He has rust in his block and is worried. So he would flush his coolant every 5,000km. My Wira has no rust and is clean throughout, I wait for 20,000km before flushing once.

    That's all really.

    And that's why it's crucial to use the right coolant because coolants have rust inhibitors built into the fluid and as long as you use distilled water, no minerals or whatever will react with the block or water to result in deposits or acidifying the water etc.

    For those who have rusty bits now, if you can change it - just do it. If you can't change it (like the block) just flush what you can and do it in shorter intervals compared to the average Joe with no rust issues. That's all really. The block will super heat the water in the water jacket anyway and a hot block + oxygen = high chances of rusting will happen.
     
  17. jimmyae101

    jimmyae101 Senior Member
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    yes..wont be rust if change coolant every 10k km...but use good brand of coolant red or green colour...normally toyota got own coolant red one for old toyota and new coolant for new model start from new altis,vios,camry,hilux and other model(import car CBU)
    of coz cant use pipe water to fill radiotor tank..no oily one ma.
    cheap way to cool down radiotor finally end up to pay high to replace if anything happen like radiotor rust or break leak,water pump...engine over heating...
     
  18. amirmambo

    amirmambo Senior Member
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    Hahahah brother youre one daring chap to just slumber test it out :nurse:..But then again,glad that it all worked out well for you,i think ill give it a test aswell,my car 10years old edi hehehe :idea:
     
  19. Charles

    Charles I brake very late....
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    Izso...thumbs up...good discovery.
     
  20. Izso

    Izso Boooooossst
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    Uh.... it's not my discovery. LOL

    Credits go to uponriversky for having the balls to try it on his newly rebuilt car!
     

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