OK, the galaxy II rad is alluminum, according to the MFG specs. Although some say you won't have issues with mixing metals, that are separated by the coolant hoses, it will speed up the oxidation of the block. From what I have read, the alluminum will try to deposit itself onto the copper block. Most likely won't cause it to leak, etc.. The worst/fastest oxidation/galvanic reaction happens when you have a copper block that is topped with aluminum.. I don't think an alluminum rad would cause your block to start leaking in a couple two or three years, but it will degrade the copper's cooling performance over time due to the oxidation, even with anti-corosive additives.
The mcw in my other post was run with off the shelf computer water cooling fluid, or a mix of distilled water and automotive anti-freeze, that had the anti-corrosive additives...
On the flip side, my gemini cool block was only run with distilled water and automotive anti-freeze. When I did a coolant change after about 3 years, I used distilled water with watter wetter, then after about 2 months of running fine, the paste sealant that gemini used on the barbs melted away and the silicone top sealant let go around the same time, resulting in leaks. Probly due to the change in chemicals, from what's in the automotive anti-freeze, over to water wetter.
Try to stick to ONE type of coolant/anti-corosive aditive, throughout the life of your parts, and probly stay away from water wetter if you have tops, or barbs that are sealed with silicone/pipe tape or even o-ringed.
The mcw in my other post was run with off the shelf computer water cooling fluid, or a mix of distilled water and automotive anti-freeze, that had the anti-corrosive additives...
On the flip side, my gemini cool block was only run with distilled water and automotive anti-freeze. When I did a coolant change after about 3 years, I used distilled water with watter wetter, then after about 2 months of running fine, the paste sealant that gemini used on the barbs melted away and the silicone top sealant let go around the same time, resulting in leaks. Probly due to the change in chemicals, from what's in the automotive anti-freeze, over to water wetter.
Try to stick to ONE type of coolant/anti-corosive aditive, throughout the life of your parts, and probly stay away from water wetter if you have tops, or barbs that are sealed with silicone/pipe tape or even o-ringed.
A copper/brass radiator with chrome plating/chrome fittings will be pretty heavy compared to an alluminum radiator.. If you can't check these out in person, ask the manufacturer of the rad so you know what metal you are getting.