Is the wrong material for the job?

[Roger440]

Ive got an aftermarket header tank ive taken off the car while i do some work. As the paint was flaking off, i thought id run it through the aqua blaster to clean it up and key it a bit to repaint.

However as you can see from the pics, its not all that well.

Given its only 4 years old, this level of corrosion suggests to me it might not be an appropiate material for a header tank. Been running blue antifreeze at 50% for the duration.

Thoughts anyone?

(yes, that crap welding near the pipe outlet. A repair i had to do in a rush as the original weld wasnt holding pressure. My first ever attemt at alloy welding though)

 

[Barking Mat]

Yep, looks pretty unsuitable to me after only four years.

Why has it rotted that much, would be my question ?

 

[Morrisman]

I’d say it’s acted like a sacrificial anode for the engine block. Is it a cast iron engine?

 

[Roger440]

Yep, looks pretty unsuitable to me after only four years.

Why has it rotted that much, would be my question ?

Agreed

Why, im guessing is material.

 

[Roger440]

I’d say it’s acted like a sacrificial anode for the engine block. Is it a cast iron engine?

Hmmm, hadnt considered that.

Its a cast iron engine with alloy heads. The header tank is not mounted to the engine, its completely isolated and connected only be 2 rubber hoses. It is though, bolted to the strut tower.

 

[Morrisman]

Hmmm, hadnt considered that.

Its a cast iron engine with alloy heads. The header tank is not mounted to the engine, its completely isolated and connected only be 2 rubber hoses. It is though, bolted to the strut tower.

Many years since I studied the topic, but I think any electrical type connection twixt the two is enough to make the least noble metal in the chain work as the anode.

 

[Barking Mat]

I’d say it’s acted like a sacrificial anode for the engine block. Is it a cast iron engine?

Imagining it is a boat, which I don't think you've specified, if it's coolant, and isolated, I'd be suprised.

 

[Roger440]

Many years since I studied the topic, but I think any electrical type connection twixt the two is enough to make the least noble metal in the chain work as the anode.

More, Hmmmmm.

Not a subject i fully understand. Bit of reading later i think. Need to do some more blasting first.

 

[Roger440]

Imagining it is a boat, which I don't think you've specified, if it's coolant, and isolated, I'd be suprised.

Its a car.

 

[Kram]

Been running blue antifreeze at 50% for the duration.

What did you make up the other 50% with? Tap water would be bad.
Deionised/distilled water or, anything out of a dehumidifier tank, would be ideal.

 

[Greeves246]

Daft question , was it new antifreeze or some old stuff you had lying round? Formulation changed some years ago with change from cast iron to aluminium engines.

Antifreeze Explained: Choosing Between Blue and Red

www.lsengineers.co.uk

 

[Roger440]

Daft question , was it new antifreeze or some old stuff you had lying round? Formulation changed some years ago with change from cast iron to aluminium engines.

Antifreeze Explained: Choosing Between Blue and Red

www.lsengineers.co.uk

New, blue stuff.

 

[Roger440]

What did you make up the other 50% with? Tap water would be bad.
Deionised/distilled water or, anything out of a dehumidifier tank, would be ideal.

Would have been out of my dehumidifiers probably. That what i normaly do. Was circa 4 years ao though!

 

[reb78]

I had similar with an ali filler plug in a brass rad tank.

Discussion here.

X Eng Rad cap corrosion

A while ago I bought an X Eng rad cap to replace the plastic one that got more and more chewed up every time I removed it. Anyway, yesterday, replacing the coolant I found the end of the cap was really corroded making it quite difficult to get the thread started again. Anyone else had this? I'm j...

forums.lr4x4.com

A few others had this as well with these plugs. Talk of sacrificial anodes and bad earth's on that thread. I replaced the cap with a brass one. None of my other ali components had been attacked like that plug.

 

[Smallfry]

Is this an "upgrade" to some classic, kit, or track car ? If so, should be using red, green, or yellow antifreeze.

I know a couple of guys who have had problems with "alisport" type rads because of this.

Years ago we had a Hillman Imp (alloy engine) and I remember dad moaning about cylinder head corrosion, despite using "Bluecol U" at 50%

 

[pedrobedro]

It is though, bolted to the strut tower

Imagining it is a boat,

A boat with suspension, novel concept It does appear to have suffered in a relatively short time. I think I would be looking for a replacement possibly a standard plastic header tank, not so bling but proven to work.

 

[dave h 2]

New, blue stuff.

According to the link 'wrong stuff'

 

[Brad93]

Do you use deionised water?

 

[Roger440]

Is this an "upgrade" to some classic, kit, or track car ? If so, should be using red, green, or yellow antifreeze.

I know a couple of guys who have had problems with "alisport" type rads because of this.

Years ago we had a Hillman Imp (alloy engine) and I remember dad moaning about cylinder head corrosion, despite using "Bluecol U" at 50%

Yes, it is. Its a triumph stag with an aftermarket header tank. They had a tank originally but it was at the bottom of the engine bay, so much lower hat the top of the engine. The issues are legendary!

I guess with hindsight, i should have moved to red/pink when i fitted this? Though i dont seem to be able to find definitive info on red/[inl in systems with copper rads?

 

[Roger440]

Do you use deionised water?

Yes. From me de-humififier