IC Engine Cooling Systems FYI

[Rustkolector]

I was doing some research on computer radiators for my latest engine project. I am aware of galvanic corrosion of dissimilar metals in automotive cooling systems and being a bit anal, decided to look in to it a little further. The link below is from an overclockers (guys that push computer graphics beyond design limits requiring liquid cooling of processors) website. It gives a good description of the problem, but goes a bit too far into the solutions. These guys are more anal than I am.

Suffice to say, the problem is real, but the solution is fairly simple. Use 50/50 premixed automotive (ethylene glycol type) antifreeze in any model engine cooling system with aluminum and any other metal in the coolant path. The corrosion inhibitors in automotive antifreeze are made for this problem, but the inhibitor concentrations are based on using a 50/50 mix. Do not use higher concentrations of straight antifreeze as the heat transfer will be significantly reduced.

As I see it, the potential problem for model builders is that even though a cooling system is drained, it remains "wet" inside for a long time. Galvanic corrosion can continue until all water (electrolyte) is gone. Hence galvanic corrosion can continue long after the coolant is drained while the engine sits idle on the shelf. The use of the proper antifreeze solution will inhibit any such corrosion whether the system is drained, or left wet.

Since we tend to use much heavier metal thickness in models than used in real life machines, many would say this is a moot point. However, I believe the model builder's art should be preserved properly, and to the best of our ability.

Jeff

Note: Ethylene glycol is highly toxic to humans and pets.

http://www.overclockers.com/pc-water-coolant-chemistry-part-ii/

 

[Metal Butcher]

Jeff, Would the safer coolant in the link below work to solve the corrosion concerns?

http://www.sierraantifreeze.com/

-MB

 

[Rustkolector]

MB,
I have no problem with PP based antifreeze solutions, but they aren't used as widely for some reason, possiblyy due to cost. As long as the anti corrosion inhibitors are in there, it should be suitable provided it is used in the proper concentration. EG solutions have been around a long time, and I think anyone that has been around engines as long as most of us have been, are well aware of the toxicity, the proper handling, and disposal of antifreeze. If you clean up your spills, and don't leave it around in open containers, your pets are safe. There are hazards all around us every day. Wareness is the key.

Jeff

 

[kf2qd]

Another possibility would be to get some Torch Coolant from a welding supply store. It is a clear solution with a small amount of corrosion inhibitor.

 

[Maryak]

Before the more modern glycol coolants, soluble oil was used. It works quite well. It's biggest problem was the oil build up in flow dead spots in the casting which lead to local overheating. Cutting fluid to cut your costs. ???

Best Regards
Bob