Originally Posted by seross69
galvanic corrosion is a electrical/chemical reaction +ions and -ions reacting. so it does not matter is you anodize it or not it is going to react and destroy your copper
.. since the aluminium is too hard.. if you believe what they say about it being to hard to have corrosion... a 216 hour salt spray test does not prove anything(during this time there was very little air that could get to the board).
Actually while reasonable assumptions, there are several statements which are incorrect. No, there will be no "destruction of copper" because it is scientifically impossible; if you look at a metallurgical anodic index .....
Brass / Bronze: 0.40
So in any anodic situation, it is the metal higher on the anodic index which corrodes or is 'destroyed'. That is why zinc is used as a "sacrificial anode".....the zinc corrodes, and is placed there so that anything lower on the anodic scale will NOT corrode. In a loop, if the bare aluminum was exposed, the aluminum would corrode, not the copper..... the copper would "receive" the scale which is easily flushed and cleaned. As the user who supplied the water block pictures said
The copper was badly tarnished, but no problem, some of that blue toilet cleaner gel and a toothbrush got rid of all that scaly gunk and brought it back to its copper shine
A flush with a vinegar / water solution or commercial scale removing solution works well too. We uses these in power plant systems and in commercial heat exchangers to restore cooling efficiency.
The significance of the anodizing process is that it is very, very hard which resists abrasion.
I have been called into solve problems like the one you describes w/ SS and salt water .... very different situation.
1. Salt water is a very strong electrolyte. You do not have that condition in a PC loop if you use a corrosion inhibitor.
2. Your plant situation was also no doubt affected by actual current flow thru pipe grounding. I'd be willing to bet no analysis was done with regard to soil conductivity if any portion of the pipe is buried. Recently replaced an underground pipe with no dissimilar metals issues .... electrical grounds to the pipe resulted in current flow via the clay soil..... we found a 40 foot section of pipe where 80% of the circumference was just a tunnel thru the clay..... the pipe was gone. As you said, in your situation, no di-electric couplings were used..... in your PC loop, you have dozens (each tube breaks current flow).
3. You had no coatings on your metals
As for the salt spray test, I am familiar with the ASTM test procedure. To the contrary, it is very much exposed to air......it's spray and fog test.... It's done in a sealed chamber with plenty of air. We don't suffocate when out in the rain due to lack or air...... the test simulates use in a seaside or marine environment.
The board isn't tested, the block is and the purpose is to test the effectiveness of the coating.
The Salt Spray Test (Fog Test) is an accelerated corrosion test used to evaluate the relative corrosion resistance materials exposed to a salt spray or salt fog at an elevated temperature. Test specimens are placed in an enclosed salt spray testing cabinet or chamber and subjected to a continuous indirect fog or spray of a salt water solution. This climate is maintained throughout the duration of the test.
Salt spray testing (fog) is popular because it is well standardized and reasonably repeatable. Salt spray tests are widely used in the industrial sector, marine, automotive, air craft, and military equipment for the evaluation of corrosion resistance of parts or finished surfaces.
Coatings provide corrosion resistance for metallic parts. Salt Fog Testing is an excellent way to test the permeability of coatings and seals. ..... The ASTM B-117 Salt Spray Test standard (and ISO 9227) are widely used reference standards to determine normal corrosion resistance to ocean water type environments.
The PC water loop comes no where near the aggressive conditions of"ocean water type environments" ..... salt is a very strong electrolyte.
Originally Posted by cyphon
Well yes a tee is not gonna work lol. And I know there are some places where it just won't work without adaptors. I tried to make everything work without adaptors first, then put the order in for all the ones I needed
Same thought here.... I'm actually going to do a air cooled build first .....I want to document the performance differences between air and water. I'll then complete the water loops piecemeal until it's ready to go.....will do the final assembly over XMas - NY holiday.