[Squirrely]

When I was designing and preparing my PC for my first loop, I discovered that cleaning a new radiator before you put it into your loop is a step which must be done.

I cleaned them by using the old staple method of using hot boiling water and shaking it around in my radiator. It did work as it got out a few chunks, but I was not satisfied with the results at all. I poked around a bit more and read about another method which uses a half vinegar/DI mixture. When I tested the vinegar rinse method I was not satisfied with the results at all as well.

That got me thinking. Seeing as I know (and hope you guys agree with me) that chemistry is amazing, I decided to nerd out and create a procedure to etch/clean all of the flux and other contaminates out of a newly purchased radiator. This method works MUCH better than a vinegar rinse.

Now lets begin....

Before we get into it lets break out our activity series. (If you remember this...then yes...you're actually going to use some of the "crap" you learned in CHEM101!)

As copper is lower than Hydrogen (H, the "eating" part of acid) on the activity series it will displace H2 when it is in presence of an acid. When you displace H2, active reactions tend to occur. This is why you are not supposed to wash aluminum radiators with an acid, as if you refer to the activity series it will displace H2 and create a non desirable active reaction.

So what's a good alternative to acetic acid which does a better job? We want something which falls under the following criteria:

1. Is fairly easy to find. Not everyone has access to lab grade reagents/chemicals.
2. The end product of this acid + copper reaction is soluble. (I'll get to this later)
3. Isn't super dangerous. Example: The badboy acid Sulfuric Acid which oxidizes and turns organic things black.

An acid which fits all 3 of those criteria quite well is Hydrochloric Acid or it's historical/consumer product name Muriatic Acid. Chemical formula: HCl

1. As HCl is used in many purposes, typically in home improvement/pool maintenance, it can be found quite easily at those stores. You may have to buy a gallon jug of it, but sometimes they sell in smaller amounts. Either way it's fairly cheap.
2. When copper is put in a HCl solution it reacts with the Cl ion in the solution. This creates CuCl or Copper Chloride. As most chlorides (including Copper Chloride of course) are very water soluble you're good to go!
3. Some people could say consumer grade (~10%) Muriatic Acid is dangerous...it can be. Just wear gloves and goggles when handling it and do not smell the vapors. Other than that just don't take a shower with it and you'll be fine.

Now...to decide what solution we are going to make for our wash. We do not want something super strong or something which is weak. So, I chose to have the wash at a pH of 2, which should get the job done just fine in a reasonable amount of time.

To calculate the pH of an acid, you first need to know if the acid is a strong or weak acid. As HCl on that list, it is a strong acid. To figure out the concentration of acid we need in moles/L or Molarity (M) is very easy:

C = 10^(-X)
Where X is the desired pH and C is the concentration calculated.

So, we need to make a 0.01M HCl solution (For you chemistry nuts .01N as HCl is monoprotic).

To make said solution, you can follow the calculations I used to make mine:

The concentrated HCl I had was listed at 38% HCl and has a density of 1.19g/mL as per this chart.

I need to get the molarity of the concentrated HCl:

1. 38% of HCl means there is 380g of HCl by weight per 1000g (1000ml) of water.
2. If the water is 1.19g per mL and I have 1000mL, the total weight is 1190g.
3. 1190g * .38 = 452.2g of HCl.
4. Whip out your periodic table! HCl has a molar mass of 36.5g (Hydrogen H is 1 and Chlorine Cl is 35.5)
5. Finally divide 452.2g/36.5g to get the molarity of HCl in your solution. The answer is 12.38M

Now we have the molarity of our HCl solution! Now we calculate how much we need in the end product, right? Nope. Who wants to measure out less an a mL of concentrated HCl? When making something with such a low concentration it is a good idea to make intermediate solutions, or stock solutions. So I decided on a 0.5M stock solution of HCl as my intermediate solution.

Now onto the stock solution creation. Remember this formula kids??

M1V1 = M2V2
(Molarity of the first solution * Volume needed = Desired molarity * volume of second container)

12.38M * X = 0.5M * 1000mL

When you solve X you get 40.38mL or ~40mL. So I put 40mL of that concentrated 38% HCl and filled it up with 960mL of DI water.

Now we are finally going to make our wash solution. To make our .01M solution we do the same thing as before with the M1V1 = M2V2 formula.

0.5M * X = 0.01M * 1000mL

When you solve for X you get 20mL. So put 20mL of that stock you made and fill the rest of it up with 980mL of DI water.

Anddddd you're done! If you read or went through all of that you get this sticker:

Spoiler: Warning: Spoiler!

You only get that sticker if you did everything.

Phew...SCIENCE OVER

But where's the shortcut?! Fine fine...I'll give you one!

Now...you could just put in ~.8 mL or ~15-18 drops (from a small syringe or similar) of concentrated 12.38M HCl in a litre (1000mL) of water. Remember...readjust the number of drops to the concentrated HCl you have. There are about ~20 drops in a 1mL aqueous solution. Where's the fun in that though?!

Now it's time to put that solution into a rig which can flush the radiator...like below:

CAUTION: Do not run an acid solution in a radiator for more than ~2 hours (changes depending on the pH) Acid works fast! If you see the water turning a blueish-green color, then the acid is working. If you see copper participating out (which will happen) then you should stop immediately (If copper is collecting in your pump's reservoir then it's also collecting in your radiator). Once you are done remember to rinse +3 times with DI water to get the acid out.


Washing my radiators with the 0.01N HCl (pH of 2) solution I made

Now for some before and after!


Before the acid wash


After the acid wash. SO CLEAN. All the flux and junk is gone.

Bonus:


Mmmm Copper Chloride

Now you have a squeaky clean radiator to put in your new loop!

Spoiler: Warning: Spoiler!

Man this Squirrely guy is nuts...

har har. Hey though...if it's worth doing, it's worth over doing right?!

 

[Wolfsbora]

Subbed!! I read through this so fast my brain hurts. I will be re-reading this very soon. Great write-up!

 

[Squirrely]

Quote:

Originally Posted by Wolfsbora

Subbed!! I read through this so fast my brain hurts. I will be re-reading this very soon. Great write-up!

Thanks!

I'll be editing and updating the writeup if an area needs improvement. I know some areas could do with some touching up.

Also it goes without saying but I'm open to questions, criticisms and suggestions! It is my first writeup on here...so be nice!

 

[B NEGATIVE]

I would be very careful about using this,HCL is used to remove solder from PCB's for recycling....seeing as the rad is soldered together....you can see where this is going.....

Plus,removing the oxide layer only strips the protection and promotes more oxide to form...each time losing a small amount of copper,not a big deal on the tanks but the tubes are very thin.

And,finally,you can do the same thing with citric acid with less environmental damage.

 

[ZytheEKS]

Seems pretty legit, be sure to do a bicarb rinse after to neutralize anything if you use a coolant, or are just paranoid about loop maintenance like me. I'd only ever do this once to strip away any flux, once it's gone it's gone so doing this after the flux is removed will just strip the copper patina, which is counter productive to loop maintenance.

 

[Squirrely]

Quote:

Originally Posted by B NEGATIVE

I would be very careful about using this,HCL is used to remove solder from PCB's for recycling....seeing as the rad is soldered together....you can see where this is going.....

Plus,removing the oxide layer only strips the protection and promotes more oxide to form...each time losing a small amount of copper,not a big deal on the tanks but the tubes are very thin.

And,finally,you can do the same thing with citric acid with less environmental damage.

The point of the wash is to remove a very thin layer of solder and take the contaminates from the manufacturing process along with it. I know the walls of a radiator are thin, but the amount we are taking off is so small that it really doesn't matter. My statement only holds true though if you only run the wash for a short period of time or use the pH i recommended. If you run it for hours on end or use a more acidic solution you getting into uncharted waters, so you will most likely will run into problems.

The difference between electronic recycling and this is they use a HCl mixture which is much more acidic than the one made here. I suspect they use a solution which has a pH of 1 or lower, as they want the reaction to happen quite quickly. A pH of 1 is way too acidic for this type of rinse, so that's why I chose a more mild pH of 2.

Remember, a pH of 1 is 10x more acidic than a pH of 2! That's due to the pH scale being logarithmic.

I thought about using citric acid instead of hydrochloric at first, but I opted for hydrochloric instead. Citric acid is safer to deal with as you stated, but because it's safer it has its downsides. Citric acid is a weak acid, so it doesn't dissociate very well in water compared to a strong acid. What this means is you will need a LOT of citric acid to get a solution down to a respectable level. It just really isn't economically efficient. On top of that a chloride salt is much more soluble and easier to deal with than a citrate salt.

If you're concerned about dumping this stuff down the drain, that's good! the thing is though the amount which is being dumped is so low it's quite safe anyway. Anyway this acidic solution is not dangerous at all either. I of course wouldn't advise it but you can stick your hand in it all day. Heck, you can stick your hand in 10% HCl (1.238M) and your hand may get a tad itchy after a min or so. HCl is only dangerous in its concentrated form, so when you're dealing with it use gloves and goggles. Remember a chemical is only dangerous if it isn't handled properly!
Quote:

Originally Posted by ZytheEKS

Seems pretty legit, be sure to do a bicarb rinse after to neutralize anything if you use a coolant, or are just paranoid about loop maintenance like me. I'd only ever do this once to strip away any flux, once it's gone it's gone so doing this after the flux is removed will just strip the copper patina, which is counter productive to loop maintenance.

Doing a sodium bicarb rise is not a bad idea at all. If you rinse multiple times (3-5) with DI water you'll get the same result though. I only opted for a simple DI water rinse as I find it's best to keep the variables (such as using extra chemicals in a procedure) to a minimum.

 

[QAKE]

Hello,

I work in chemistry, and I would just recommend you a better acid for this purpose:
The Phosphoric Acid (wiki link HERE)

It is also used by Mayhems Company for their radiator flush kit

The best would be a mix of HCl and H3PO4 (5:1 , 5 parts of H3PO4 for one part of HCl)

A pH of 3.75-4 would be recommended, and let it work for at least 4-5 hours to have a good corrosion protective layer of CU3PO4

Why?

- Less dangerous emanations of Chlorine (former used as a mortal gas in 1st World War)
- Is fairly easy to find in Drug Stores
- End product is protecting Copper from further corrosion (H3PO4 make a protective layer of Cu3PO4 on the Cu)
- Is also a strong acid
- Remove Copper "rust" (oxidation with oxygen in the air and in water) (Cu2O, black-red color)
- Remove Copper "rust" (oxidation with CO2 and oxygen in the air or with CO2 and water) (CuCO3, green color)
Quote:

WIKIPEDIA: This process can leave a black phosphate coating that provides moderate corrosion resistance (such protection is also provided by the superficially similar Parkerizing and blued electrochemical conversion coating processes).

 

[NASzi]

bought a new radiator, ran some warm water through it, slapped it in my rig, bam good to go

 

[QAKE]

XSPC Rads are REALLY clean.
Alphacool is the worst company for the cleanliness of their rads (not talking about build quality)

So not all of the rads needs to be correctly flushed to avoid getting particles in your water loop

 

[ZytheEKS]

Quote:

Originally Posted by QAKE

XSPC Rads are REALLY clean.
Alphacool is the worst company for the cleanliness of their rads (not talking about build quality)

So not all of the rads needs to be correctly flushed to avoid getting particles in your water loop

xspc uses ultra sonic cleaning. They basically use ultrasound to make everything in it vibrate, then flush all the crap out It works very well, i wish more companies would be held to that standard.

 

[B NEGATIVE]

Quote:

Originally Posted by QAKE

Hello,

I work in chemistry, and I would just recommend you a better acid for this purpose:
The Phosphoric Acid (wiki link HERE)

It is also used by Mayhems Company for their radiator flush kit

The best would be a mix of HCl and H3PO4 (5:1 , 5 parts of H3PO4 for one part of HCl)

A pH of 3.75-4 would be recommended, and let it work for at least 4-5 hours to have a good corrosion protective layer of CU3PO4

Why?

- Less dangerous emanations of Chlorine (former used as a mortal gas in 1st World War)
- Is fairly easy to find in Drug Stores
- End product is protecting Copper from further corrosion (H3PO4 make a protective layer of Cu3PO4 on the Cu)
- Is also a strong acid
- Remove Copper "rust" (oxidation with oxygen in the air and in water) (Cu2O, black-red color)
- Remove Copper "rust" (oxidation with CO2 and oxygen in the air or with CO2 and water) (CuCO3, green color)
Quote:

WIKIPEDIA: This process can leave a black phosphate coating that provides moderate corrosion resistance (such protection is also provided by the superficially similar Parkerizing and blued electrochemical conversion coating processes).

Particularly important for stainless steel parts,ie Jet plates,GPU covers....

This fascination for acid cleaning is just not required in a normal water loop,Mayhems requires acid cleaning for a few of his coolants in combination with a few rads but he is the only one.

Hot tap water flushes and DI,tried and trusted.

 

[JimBoNetic]

Hi, that's a very comprehensive guide you wrote here!

I'll buy the HCI tomorrow (I think we have 31% solutions here in CZE), and I'm going to maintain my loop (420+280 rads).
My question is:
Is it OK for my pump and blocks (what about the rubber o-rings?)?
I'm thinking to keep the old loop connected, do the flush with your solution, then flush it with DW few times, do fresh tubing, fill and voila

Do You think this will work?

The rads are full copper, the CPU block is full copper, pump is VPP655, all Alphacool.
GPU block is nickel plated/plexi, reservoir is also plexi and fittings are black nickel, all ekwb.
Tubes are PrimoChill PrimoFlex Advanced LRT clear ones (well, a bit misty already now after over a year of running

)

Thanks anyone for advice.

 

[Andrew LB]

I've used Tri-sodium phosphate TSP in the past for cleaning copper plumbing/HVAC fittings and it works wonders. I bet it will clean out a nasty rad very well.
Quote:

Originally Posted by ZytheEKS

xspc uses ultra sonic cleaning. They basically use ultrasound to make everything in it vibrate, then flush all the crap out It works very well, i wish more companies would be held to that standard.

Ultrasonic cleaners are amazing. I bought one a few years ago and use it for all sorts of stuff. They don't vibrate objects to clean them, but use very high frequency sound to cause micro-cavitation bubbles in the solvent solution. They sell a cheap one for about $70 on sale at harbor-freight tools but in all honesty, if you use it frequently it wont last very long. I own this one made by Kendal which has two transducers and its is amazing. Just don't do something stupid like sticking your hand in it while its running.

 

[JimBoNetic]

So i did try it yesterday... The maintanance of the whole computer took me merely 15 hours...

Anyway... it did not work!

I dunno what did I do wrong.. maybe calculations?

31% HCL
cca 50ml added to 950ml of DW
then 25ml of that stock added to 975ml of DW and filled the loop with it.

I left it for 2 hours, nothing, not a slightest change in colour of the fluid.
So another 1h + I added 5ml siringe of the 31% HCL...still nothing
After another 2 hours of NOTHING, I gave up.

What did I do wrong? Must be the calculation..:/

 

[Uroborous]

Well that's one serious and useful thread!

My problem is this : I noticed that the inside of my ek pe360, somehow turned almost black. One guy told me to buy a certain home cleaning product that is one part hydrochloric acid and nine parts water (1/10). I should fill the radiator with it and let it for about 12 hours. Do you think it is going to work? I firstly noticed that my liquid turned blue and this is how I investigated the rad inside. the waterblock was very clean (ek supremacy evo full nickel) and so were the fittings. Should I throw out the tubing or can I clean it? (Ek zmt).

Thanks in advance.

 

[Ashcroft]

Well that's one serious and useful thread!

My problem is this : I noticed that the inside of my ek pe360, somehow turned almost black. One guy told me to buy a certain home cleaning product that is one part hydrochloric acid and nine parts water (1/10). I should fill the radiator with it and let it for about 12 hours. Do you think it is going to work? I firstly noticed that my liquid turned blue and this is how I investigated the rad inside. the waterblock was very clean (ek supremacy evo full nickel) and so were the fittings. Should I throw out the tubing or can I clean it? (Ek zmt).

Thanks in advance.

You shouldn't use anything acidic on nickel plated blocks, or anything else, so be sure to take it apart and thoroughly clean it. Just flushing it out won't quite do the job as there are areas where fluid can be trapped.

Personally I have owned and used many rads from different manufacturers and never cleaned any but the Alphacools. It never caused me any issues.

 

[Uroborous]

I am not talking about nickel plated surfaces. I want to clean the inside of the copper rad.

 

[Kana Chan]

Just don't do something stupid like sticking your hand in it while its running.

Do you happen to know the effects of this? Did you put your hand in?

 

[ryan92084]

Well that's one serious and useful thread!

My problem is this : I noticed that the inside of my ek pe360, somehow turned almost black. One guy told me to buy a certain home cleaning product that is one part hydrochloric acid and nine parts water (1/10). I should fill the radiator with it and let it for about 12 hours. Do you think it is going to work? I firstly noticed that my liquid turned blue and this is how I investigated the rad inside. the waterblock was very clean (ek supremacy evo full nickel) and so were the fittings. Should I throw out the tubing or can I clean it? (Ek zmt).

Thanks in advance.

Is it black as in a goo? Or just the natural result of copper oxidation? Give it a swab to test but for the latter I'd just give it a good rinse for peace of mind.

 

[Uroborous]

Ι thinks it is black goo. I did this: I put hydrochloric acid solution of 9% and left it inside the rad for 8 hours. After that a few black particles left out. Two days later I put in a solution of 16% for 5 hours. You wont believe what came out of it. Companies should be ashamed to sell the rads in such a condition. However the inner surface (brass I think) did not came up shiny out all. It is dark and cloudy.