citric acid to remove radiator rust

upontheriversky

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Dec 31, 2007
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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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arturo

nooB
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Aug 5, 2004
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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.
 

Veloc

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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.
 

risyia

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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.
 

eohl79

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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.
 

upontheriversky

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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?
 

eohl79

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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.
 

upontheriversky

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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:


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:


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
 
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blitzs360

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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
 

eohl79

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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.
 

wafuk

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May 6, 2011
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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.
 

eohl79

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Jun 12, 2011
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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.
:argh: Wah! :hmmmm2: Headache! :dontknow:
I would go with a good bottle of radiator coolant/anti rust instead.
 

upontheriversky

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Dec 31, 2007
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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.
u have a good point, i didn think of that before proceeding, now im a bit scared..
 

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