I take your point Rog, I wouldn't want to make a battery!

TBH the plan was to mount the brass tank on rubber cotton reel bobbins so it never directly touches Monty's chassis. My thought being if the brass tank is completely insulated from the chassis, the ground path is removed and the galvanic corrosion issue would be eliminated.

However, thinking about it, even with perfect chassis isolation the coolant flowing through Monty's system would itself act as a liquid wire (electrolyte). Over time, high temperatures, fluid velocity, and chemical breakdown could potentially cause tiny amounts of noble ions to leach from the brass tank into the coolant.

The answer would be to switch to a waterless coolant like Evans, because waterless coolants do not conduct electricity or support ion transport, the result being the galvanic action would drop to zero.

The brass tank would look great and it was cheap too, but Evans coolant isn't cheap and I prefer my Prestone coolant mix. As it stands, and in the unlikely event I had a catastrophic coolant hose failure, replenishing the lost coolant would be easy as I could just fill with water. With Evans, if you're not carrying a spare supply of the stuff you're kinda screwed, and carrying a spare 5l jug of Evans waterless coolant is not a very practical option in a Morgan.

Oh well, I think I'll sell the lovely brass tank to my local classic Mercedes restorer for one of his minted SL Pagoda customers, as it does look like for complete peace of mind the only truly safe way to replace the plastic tank is to go with aluminum. Here's the best option I can find and at £168.00 delivered it's reasonably priced, paying the £300 - £400 being ask by others seems excessively expensive for a tank.

https://www.sico-developments.co.uk...ight-alloy-water-header-tank-replacement

[Linked Image]

As this tank is specifically designed for a Mk1 Focus the brackets should all line up on Monty, my existing hoses will fit without modification too, and finally it looks like it may even fit neatly between Monty's wiper motor and the heater box for a really clean look thumbs

I only paid £17.00 for the screen wash tank, so that's £185 for the two tanks which I think is tolerable for what's essentially just a vanity project. Saying that, the under-bonnet plastic does really bug me, so it was always going to be eliminated at any cost spend

Thanks for the warning Rog cheers