May 31, 2020 - 05:23 AM
1) How to clean new devices before immersing them.
We recommend that you always clean all devices prior to immersing them in your SLIC System. We find that servers, miners, and just about all other electronic devices come from the factory with some amount of manufacturing debris on them. This can be waxes, greases, and other similar materials intentionally placed on the device as a protective film for storage and shipping purposes by the manufacturer or just basic dust, dirt and grime that wasn't removed or gathered during storage. Used equipment, especially devices with fans are generally filled with dust and dirt, and you definitely want to remove this BEFORE immersing them as the amount of dust can be considerable.
Step 1) Compressed Air Cleaning
We recommend using medium pressure air (about 50psi) and a tight air nozzle gun to blow off as much of the debris as possible, for used equipment, you'll want to focus on the heat sinks and any surface that was facing the fans. You may need to use a light bristle brush to remove any caked on dirt, and before to look under the edges of any heat sinks as dust is often trapped there. We have a nozzle that we made for our shop that has a short 90deg bend in it to help get under overhangs like heat sinks. For new equipment, a light blow over is usually sufficient, and a good way to see if there is anything built up on the boards. Be very careful with how much air pressure you use and how close you get on the boards, we've have seen customers using high pressure air nozzles blow memory, capacitors, and other modules clean off the boards rending them useless.
Step 2) Agitated Rinse in Coolant
After removing as must of the debris as possible, the next step is to rinse the device with the Dielectric Coolant you will be using.
We get a lot of questions about using our DS-100 Dielectric Solvent to clean devices prior to immersing them. While you can use our DS-100 to clean devices prior to immersion, you will have to wait until the device has fully dried before immersing it as you don't want to bring active DS-100 solvent into your SLICTank. We really only recommend using DS-100 when you are trying to remove the Dielectric Coolant from a device that has already been immersed.
Using the Dielectric Coolant that you'll be using in your SLIC system is the best way to pre-clean your devices prior to immersing them for operation. This will remove any waxes, greases or protective films and it will remove dirt and debris as well. There are a couple of different ways to clean your device, the simplest method, and the one that we use for miners is simply to fill a 5gal / 20L bucket about 3/4 fill of Dielectric Coolant (if you are using BitCool you can use the 20L bucket it comes in, just pour some out first in to your tank) and then place the miner into the bucket of Dielectric Coolant and agitate the device a few second under the coolant. Make sure that you get the device completely immersed in the coolant while you are agitating it for about 5-15secs (depending on how dirty your device is). You want to move the device around in the coolant briskly (agitate it) in order to make sure the Dielectric Coolant enters all areas of the device. Then remove the device and place it on another bucket with a piece of mesh over it to allow the coolant to drip off and remove the material, you can go back and forth between using the coolant in the two buckets to clean off the miners. There is no need to use clean coolant for every miner! We can usually clean about 100-150 new miners with a single bucket of 20L, and about 50-75 used miners.
For servers, the easiest method is to set up a "wash station" using a small oil transfer pump and a large plastic or metal tank, At our lab we use a tall acrylic tank that is largest enough to hang the server in with some distance between the bottom of the server and the pooling coolant. Our tank has three tall sides and a 1/4 front panel so that most of the server is accessible from the front. We then fill the bottom of the tank with about 20L of coolant and using the pump connected to the bottom of the tank we spray the Dielectric Coolant over the entire server using a low-pressure nozzle on a flexible hose. We rinse the server on all sides from top to bottom for about 5-10secs and then allow the coolant to drip off the server for a few minutes to remove any debris.
Another technique is to lay the server down in a pan and spray or pour Dielectric Coolant on the server and stand it up right to allow it to drain off.
For new servers and miners, we have many customers that simply immerse the devices directly in their tanks and rely on their filtering systems to remove the debris, for used devices we DO NOT RECOMMEND this as the amount of debris you may put in your tank could clog your pumps or worse your dry coolers.
2) What kind of filter system should you use on your SLIC tank
For filtering we recommend the use of by-pass filtering system where you only take a very small portion of the total flow in your system (0.1% - 0.5% of total flow max) and filter it using 30micron diesel fuel oil filters. We recommend the use of spin-on diesel fuel filters, or replaceable media filters. You can use any high quality diesel fuel filter, we generally do not use spin-on water separation filters, while they work very well, we prefer to use the clear bowl replaceable media filters as you can see if there is any water accumulation in your system. Unless you are in a very humid environment with a lot of condensation, you will probably never see any water accumulation in your system unless you have accidentally have dropped something in your tank (see this video of what happens to a server when you pour water all over it while it is operating in a tank of ElectroCool).
We recommend that you replace your filters after the 1st three months of operation and then annually. Also, we recommend that you always inspect the filter media (just cut open the spin-on filters) to get an idea of how much debris you are trapping, this will give you a better idea of how often to replace the filter.
3) How to remove any debris from your system
Even if you are diligent about cleaning and filtering your system, you may still get some debris on the bottom of the tank. This is normal and it will rarely effect the dielectric strength of your Coolants, unless you are in an area that has high levels of aluminum or iron dust in the air (if you location is near aluminum or iron works you need to take extra care in sealing the lids and filtering your coolant in your tanks. (I'm sure you asking why would anyone place SLICTank in location near these types of factories - the answer: lots of (often cheap) electricity). The easiest way to remove debris on the bottom of your tank is with a wet dry vacuum and a narrow PVC pipe (you can use cheap schedule 20 white PVC for this application as you won't have the pipe in the Dielectric Coolant for very long and if the pipe becomes brittle just replace it). Attach the pipe to the vacuum (we recommend using a vacuum with a stainless steel tank) and suck up the debris on the bottom of the SLICTank. Once you have a full vacuum, allow the vacuum to sit undisturbed for 3-5 days, when you open vacuum you'll see that all of the debris will have settled on the bottom of the vacuum tank. You can now remove the coolant from the top of the tank and pour it back into your SLIC system, leaving only the last 50mm / 2" of Coolant in the bottom of the tank for recycling or filtering. To filter out the last portion, we use a large funnel with a piece of paper towel over the bottom of the funnel and stuck into the stem of the funnel. We then just pour the dirty Dielectric Coolant into the funnel and allow it to filter through the paper towel (turns out one layer of decent paper towel is roughly the equivalent of a 40micron filter. Do not believe - then check out these toilet paper oil filters designed by John Franz).