Metal coolant reservoir...
 

I got to thinking last night...

Is there a reason why the coolant reservoir couldn't be metal? Wouldn't that eliminate wear/tear/failure?

Hmmmm......

We looked into this years ago; one in aluminum, fabricated as a direct replacement, including a level window, was quoted at $1170 each by an excellent metal fab house, minimum of ten done per run.

That ended the discussion.

Jeff......
 

....I'd pony up for one.

Just sayin'.

:cheers:

That's a lot of quid. Would it have to be fabricated as a "direct replacement? Couldn't it be a simple square design? Isn't it just a "box" in the scheme of things? One line in... one line out? Hose here... hose there...

It's not rocket science.

Continue...

The factory tanks have multiple lines, including a entrapped air/coolant vent for the oil cooler; leaving any of these disconnected is going to cause problems with the system. As for shape, people asking at the time wanted it to fit in neatly were the factory unit sits; discussions with the fab shop about shape noted that it did not matter much to the cost if the new tank matched the factory unit's shape, or was simply a square or round tank, the real fab costs were in the viewing window (and yes, we looked at using a simple tube for the level) and testing and verifying the unit met pressure/vacuum level requirements. All this takes time, and time in a fab shop is $...………….

As long as people are talking about this topic, I thought I'd bring up an idea I had...

I'm betting most of us have seen those "Flex-Seal" commercials...

"We cut this boat in half..." "...even seals underwater..." etc...

I've thought of coating the outside of my tank with it. I'd put masking tape over the level window, and slather a thick coat of the stuff over the entire outside of the tank.

That way, there'd be no problem if the tank eventually cracked, even if it was at a seam or where the supports attach.

Before applying the Flex-Seal I'd wipe the outside of the tank down with a rag and some kind of solvent/cleaner (rubbing alcohol, whatever...) to remove any oily residue so that I'd have a good bonding surface.

Flex-Seal is basically rubber, so it should allow for some expansion/contraction of the tank (as it heats up and cools down) without de-bonding.

Again, just a thought...

If I ever end up doing this I'll post pics and/or a how-to...

(would probably have to be done BEFORE tank failure to provide the best bonding surfaces...)

thoughts?

That boat in the ads is not running on 210F water/glycol mixture at 18 PSIG. Knowing what people have tried (unsuccessfully) to "get the car home" after a tank failure, I don't think any kind of tape is going to do it...………..

That would also be equivalent to painting with that sealant paint the walls and floor of your basement hoping it will keep the water from pushing through. The pressure will win in a short amount of time.
Now maybe fiber-glassing the tank and sealing with epoxy coating before install might work

Unless you cover the inside of the tank..

Because bits of crud blocking up coolant passages is cool. :cool:

:p :D

I wonder if fuel tank coating would hold up on the inside of the reservoir tank ? The one I just replaced came unglued at the top seam where black plastic meets white plastic . Maybe an internal coating could have fixed it. But you would lose the viewing window .

When, not if, my tank goes... that's the route I'm going to take. I'll make that thing bulletproof. It'll be hidden behind the carpeting, so I wouldn't care what it looked like. It'll be, like, 2 inches thick with fiberglass and epoxy. And not some measly two-part epoxy. Nope. I'll source some ridiculous 30-part stuff.

Continue...

Particlewave, actually there is a product called POR15 that it was designed to protect the underwater metal surfaces of the offshore oil platforms (you can apply it under water..!), it is nasty to use as you would Not be able to remove it from your skin.. (you have to wait until the sking re-grows..), but once it cures you will not be able to remove it.. it is very thin liquid so should be able to apply easy (as long as you are wearing long heavy duty rubber globes)

I use it once to reline the inside of a leaky X1/9 fuel tank, it does work..

Indeed....
 

...I POR15 coated a fuel tank on my old Ducati.

great stuff.

I did POR15 inside the tank and over steel parts like suspension arms, etc. with success, so I trust that stuff. And it is nasty when it gets on hands...

But I do not think it sticks well to plastic surface... without rough porous surface it can peel right off.

Boxtard, you have a point on plastic..

Ok, Plan B..?
Perhaps be by using an Epoxy (again on the inside), as I have done it as well on the X1/9 coolant recovery tank.. Please note that the X1/9 tank is shaped much simpler than the 986 tank

As once the Epoxy is fully cured, is definitely Not going anywhere the challenge would be to have a mix that is "runny" (..?) enough to let you cover the inside of the tank.

Frankly it seems more risk than reward to coat inside the tank.

Never had the issue but it could just be a PM item, while keeping the cooling system in good shape, with fresh coolant filled without air trap, proper vent cap, temp sensor, water pump and LT thermostat, radiators with clear flow passage and elec fan working at both speeds with working resister, etc. to keep the temp cool and under proper pressure.

High temp, overpressure and oxidated coolant (from trapped air, cavitation) could cause plastic deterioration and excess stress to cause leakage from the tank, if not just aging and something to expect for 20 years old cars....

Gilles, Thanks to your 'coating' I bet the coolant tank and gas tank were the only parts on your X1/9 that didn't eventually rust out! Just kidding, I had a '78 X1/9 and loved it. I wish I never sold it.

But by the you have gone to the time and effort to remove the old reservoir, why not pitch it then, and just replace with a new one?

Assuming roughly 15 years or so use received from what I assume to be the original reservoir, a new one installed today takes you out to the year 2033, without the worry that your "patch job" on the old one will hold.

Thanks - DM

P.S - Quite glad that my 1978 X1/9, which I bought new, came with a SS tank! Pictures for the curious: 1978 X1-9 by dave80gtsi | Photobucket

Thinking a little outside the box , any chance a better/stronger tank could be made by a 3D printer ? And if it could be made are multiple layers of plastic better or worse than the OEM tanks glued seam ? Sure would be nice to have an aluminum tank but would need to know how all the internal ports work for the hoses .