hydrx recommendations?
 

I have a loop with copper and alu exposed, and it's going to stay that way. Total capacity is about 35 oz.

I'm running 30/70 glycol/water right now due to corrosion worries. Will I be safe with just hydrx and water? I wonder if one 2 oz. bottle will be enough.

AFAIK HydrX doesn't prevent reactions between those materials. You'll need something like Zerex Racing Super Coolant.

It does prevent galvanic corrosion, that im pretty sure of. Im uncertain of the amount you will require. Try emailing swiftech directly.

one 2oz bottle treats 1 liter
read the label

And that goes for any metals in the loop?

My situation is different in that I have copper water blocks and an aluminum heat exchanger exposed and don't want pitting at either end.

If zerex is a better choice, can someone give a proper dilution for this setup?

jman you are channeling BillA this am :)

Valvoline recommends 10%. Some racing engines have copper radiators, so bare aluminum and bare copper/brass. (Actually I think some racing engines out there have iron blocks due to regs - but we're not worrying about iron here...:))
I've been using it for a few years at this dilution and have not had problems with precipitation.

yes, any metals (not silver and aluminum)
swiftech uses Hydrix and a lot of their blocks are AL/copper combos
even though they are anadized (sp?) swiftech must prepare for scratches and imperfections
bill adams recently said that Hydrix contains eythonal gycol

personally, i use Hydrix (i have 2 wb w/ AL/copper) and i've had no pbs
but i did slightly over concentrate the solution - 2.5-3 oz per liter

The glycol content is really low, though...

Yeah, I called swiftech about this. Not sure who I talked to, but they said bare alu and copper was a no-no with hydrx.

I said what should I do. He said take the alu out of the loop. That cracked me up. Heh, could have been talking to Bill. Unfortunately, the alu is the loop. It's my heat exchanger, and unless someone wants to design and build a copper one of the same dimensions for me, I'm stuck with it.

So 10% zerex/water will protect an alu engine with copper radiator? That would be great. From what I've read, 30/70 glycol/water actually loses you a lot of cooling performance.

andy497,
I ran bare aluminum and copper in a loop with the recommended mix of hydrx for almost a year, worked fine.

I use distilled/af/and iodine now just because of the price though =\

Beware of precipitated iodine. I am not a chemist, but I believe you could form iodine salts that precipitate out. Any solids will void a pump warranty because it's like sand in your shorts (good abrasive).

Instead of a biocide, I prefer keeping my loop hidden (no bling for me) from light, and just regularly perform a coolant flush.

I wouldn't expect any salt crystals to form. Iodide should be pretty soluble in 25-30C water, and the antifreeze will keep cations complexed that would otherwise complex with it.

It's somewhat redox active though and oxidizes from I- (-1) to IO3- (+5). So in principle I- could also dump those electrons in your loop by attacking aluminum oxide coatings (e.g. anodizing) and reducing them. That wouldn't be a problem initially, but that could drive the deterioration of the anodized layer as the aluminum oxide that eventually forms won't be as stable as the anodized surface. I don't know all the redox half potentials off the top of my head though so I don't know if this is a realistic concern in a typical loop we'd use. I seem to recall something about anodized surfaces still slowly corroding and releasing Al3+ in seawater though (which contains a good bit of iodide).

Just drained a bare aluminum + copper system after running for 2 months 24/7. Drained it into a gallon jug and there was nothing in the coolant except a little black spec (size of a grain of sand or two) that looked like something I should have cleaned out of the rad before installing =\
Was a good half a gallon+ in there too.

You can't see what is going on inside your parts though. If you oxidize the copper to a Cu(II) hydroxide then it'll have a big effect on heat transfer and the same goes for the aluminum in your rad. Without antifreeze or some corrosion inhibitor, that WILL happen quickly in mixed metal systems.

I can see inside my radiator though. Internal fins still look smooth and shinny. Its a transmission cooler, not a HC or aluminum radiator.

the parts that I can see from the inlet/outlet of the mcw6000 looks the same as when I bought it too.

hmm - don't see how you can see inside your transmission cooler (unless mr scott gave them the secret of transparent aluminum...)
:shrug: ;)

Why not just use antifreeze?

The big hole in the top and bottom? 12" transmission cooler:

http://filebox.vt.edu/users/jtorres/...C/PICT0022.JPG

as I said, Not a HC and Not a normal radiator.

ahh - i stand corrected: i've only ever come across this kind of thing(s)....
http://www.etrailer.com/Merchant2/me...gory_Code=TRAN