Res Questions.
 

I'm in the process of putting an external radbox together and the layout will have the rad at the top, pump and res underneath.
I'm thinking of using the HDPE res but the layout will make it very awkward to fill from the top fill point on the res. (only 1 side of my radbox is removable and its not the side the fill port will be on).
So, I find myself thinking that maybe I can use the 2nd inlet port on the res attached to another, more easily accessible, fill port in the top of the case.
Anyone see a problem with doing that??

nope
but you will find it easiet to fill & bleed if that inlet is the highest point in the res
maybe put the res on its side

Stick a barb in either the spare inlet/outlet or the current HPDE Res's fill hole. Run a length of tubing to a suitable location, install a DangerDen FillPort.

Currently, the way my radbox is panning out, the HDPE will be on its side and I will be running a fillport line to either the spare res connection or the res fillport depending. :)

marci

why encourage the use of AL? (DD fillport)

I believe that in this case it will essentially be unexposed to the main flow of the loop, and therefore not likely to cause galvanic corrosion.

ditto
we are now 4 steps from no aluminum,
its been a long process (and I must fight to block new aluminum products !!)
but I would note, as have others, that we do not see any problems with aluminum if an inhibitor is used
-> but there is no gain in fighting customer perceptions

is it contact with the coolant that causes corrosion or cavatation in the coolant?

my understanding is that mere contact causes corrosion
remember it's a flow of electrons that we're talking about

cavatation can make it much worse, though i doubt we experience it at the low flow speeds and low temperatures found in wc systems

while using inhibitors will work (assuming he is AL free currently, big assumption) why add AL to a copper only system.

a good looking and effective fillport can made from plastic or copper parts bought at a local hardware store (not sure about in England) for less than the DD fillport

if you quote junk sources you will never figure it out
many many books on this subject

was that directed at me bill?

not you, your quote - its wrong; otherwise yes
don't use the forums, you have no idea if the 'answer' is right or wrong
google it fro serious references, or ck out a book on the subject

i do have a lot of practical knowledge on the subject
i've spent 25 years protecting yachts from seawater and large expensive diesel engines from their coolants and the seawater they use as a cooling source

now, help me out a little

what exactly is wrong with my post/information?
is galvanic corrosion not a flow of electrons?
or that the fillport is not connected the sources of copper?
this is just not smart, if it's a metal rad box and there happens to be a ground short, well good luck or if any of the mounting bolts happen to touch the case and the case touches the rad box....
when i said this, "while using inhibitors will work (assuming he is AL free currently, big assumption) why add AL to a copper only system."
i meant that it is not a good idea to add AL to a copper system because why add risk
cavitation can be a serious concern in the cooling systems of marine diesels

thanks bill

Could you possibly mean something other than cavitation?
IMHO cavitation is when there's enough shear on a liquid to cause it to change state - bubbles on a propeller that's "pushing too hard" for instance.
It's certainly not a good thing, and the shock waves from cavitation-caused bubbles collapsing can cause metal erosion (I've seen pictures but not an actual object damaged by cavitation) but I just can't figure out how this relates to electrolytic corrosion.
BTW, I had thought the electrolytic reaction was primarily with metal ions in the water, but IANAC (I am not a chemist).

no i meant cavitation but i meant it as something else that can damage metal
i've seen elbows in a cooling system that had holes eaten though the metal
i said it because it was mentioned that being in the main flow is an issue

yes metal ions are part of the issue but the biggest problem is the flow of electrons which create a battery effect (was the first source of electrictal energy)

"Originally Posted by mastermind2004
I believe that in this case it will essentially be unexposed to the main flow of the loop, and therefore not likely to cause galvanic corrosion."

this post is wrong, that is what I was referring to
IANAC too, all this stuff is known and has been cussed and discussed over and over - sorry

Silly me. I was assuming that there would be an air gap between the fillport and the water of the loop, and I thought that would inhibit corrosion. Is that a poor assumption or am I just completely wrong?

warm saturatrated air is a classic corrosion test environment
there was a whole thread on this not long ago
there is NO NEED to speculate when good info is a google away

That makes sense then. My apologies for having missed that thread, and trying to intuitively think through something.

no problem with intuitive thinking
- then ck it out
only takes a min or two to sort through (and you will seem so much more clever too)

Didn't need/use the fill line after all. I mounted the res on its side, this way when filling, I can turn my radbox on its side, making the res easily fillable the normal way :)
Works really well, pics to follow soon.