If you’re a serious computer enthusiast, there is no question you have a computer with a liquid cooling system somewhere. Liquid cooling is a very efficient to remove the heat from your screaming processors while keeping noise levels down.
The majority of liquid cooling systems use a combination of aluminum of copper radiator and aluminum or copper waterblocks. Most people take care of their systems initially by using distilled water as a coolant, wetting agents and algae killing additives to prevent corrosion and mineral deposits. Another way to prevent these things from happening is to replace your coolant regularly, keeping the system clean and free of debris.
Though let’s face it, eventually you start to find nasty gross particles floating around in your blocks, or discoloration due to the natural way in which liquid stagnates and metal oxidizes. Unfortunately these factors can lead to restricted coolant flows, clogs and ultimately affect your waterblocks from providing peak performance. That is why it is a good idea to clean your waterblocks from time to time and keep them performing like new.
In this article we will be performing a routine cleaning on a set of Danger Den waterblocks: Z-Chip and GeForce4 Blocks. These blocks have been used for 12 months in a closed loop system. The radiator was a Black Ice Extreme Copper Radiator and the coolant was Distilled water with 1oz Water Wetter additive.
Prepwork
Before starting, I always like to take a strip of painter’s masking tape and cover over the lapped machined surfaces. This provides some protection from scratches while storing or handling your heatsinks.
These particular blocks use hex head screws. So with a gentle twist (Note: Be careful with Acrylic tops, Acrylic can be brittle and crack.), the screws are removed and the blocks can be fully disassembled. Unfortunately not all manufacturers of liquid cooling components provide for disassembly of their products. For me it is a main selling point when I go shopping for new water cooling components.
Here you can see some of the residues left on the acrylic tops from such a long period of use. Most likely under closer inspection, you could find a similar residue over the surface of the interior of your copper blocks. Just as dust hinders the performance of air cooled heatsinks, these residues or corrosion can hinder the performance of you blocks by adding another thermal interface material between the coolant and the surface of the copper.
(Note: The red color you see is from a UV dye that was added to the coolant. Over time it has stained the epoxy sealant used on the barbs of the block.)
Many traditional blocks use a similar design to these Danger den blocks, with a base and top mated with a rubber O-ring. You can leave the O-ring in for cleaning but I prefer to remove them. I have found the best way is to use a very small jewelers flathead screwdriver. Insert the screwdriver into a rounded corner where the O-ring slightly pulls away from the side of the block. Make sure not to stab or rip the O-rings, otherwise you may have leaks and find yourself buying new O-rings or new computer components.
Once the blocks are fully disassembled, we can move on to cleaning. For copper blocks it is important when cleaning to use an acidic cleaning agent. This will eat away at any residues and oxidation, leaving only bare copper, just like how you bought it. There are many copper cleaners on the market, but personally I like to use something that’s a little more readily available, plain old garden variety tomato Ketchup. Ketchup has vinegar which is acidic and salt which is abrasive for scrubbing. This is a good thing to remember too if you own copper pots and pans. Ketchup is much cheaper than copper cleaner.
So to clean your blocks, spread the Ketchup over the interior of your block. If you have highly corroded areas (black or brown in color), scrub them vigorously for several minutes with your finger. Sometimes you may find dark fingerprints on the outside of your block, spread a thin layer over those too. After spreading and scrubbing, leave a layer of Ketchup on the block for 25-35 minutes. This will give the vinegar time to work. Once the Ketchup has done its thing, you can rinse the blocks off with hot water. Take your finger or a brush with plastic bristles (like an old toothbrush) and scrub off any residue or corrosion left behind from the rinse. The vinegar in the Ketchup should have loosened it from the surface enough that it should come off easily. If not, then repeat the process and let the Ketchup set for an hour or more. Just don’t let it dry on the surface.
If your blocks have Acrylic or Lucite tops, many times you will find a white or brown residue. This can be easily cleaned using warm water and a mild soap. There are also polycarbonate and plastic cleaners on the market which do a great job too. Make sure not to use abrasives as they may scratch softer plastics.
Assembly
After rinsing the blocks should be clean and corrosion free. Now all that’s left is to dry them off and reassemble. Make sure you set the O-rings properly and that they are soft, not dry and brittle. That would mean that they may not hold a seal and they need replacement. Also, if you have an acrylic top, don’t over tighten the screws! Acrylic is brittle and cracks easily. One quarter to one and a half turns after the screws become snug is normally fine to seat an acrylic top. As a rule of thumb, it is always a good idea to fill and leak test your cooling system after reassembly of your waterblocks. You wouldn’t want to kill any computer components due to leaks you could have fixed easily.
Conclusion
Routine cleanings of your waterblocks are something to keep in mind if you want to keep your system performing at its peak. Not only does it give you a reason to drain and refill your coolant, but it will help keep your new waterblocks up to snuff for years to come.