MTFCA Forum

Hello.
Today I decided to drain all water from my Lizzy and to seal the upper hose to radiator neck (there it started leaking with decreasing temperature in my garage (now I am at +7°C).
I will keep the system dry till spring, so I don't have to worry about freezing at all (I had pure water in it for testing cooling efficiency).

Well, the radiator neck looks like new, the radiator repair company has grinded off all residue from the brass before re-soldering it to the radiator. Sadly, there is no bead on upper and lower side, this is for sure the reason for leaking.

The upper neck on motor side was not leaking, but it has deep corrosion dents. I used my little angle grinder with a sandpaper disk to smooth it without removing too much metal, but there are still some deeper dents, especially in the bead, so I am afraid this will become the next problem.

Here you can see two short videos of radiator-neck and engine-neck, if you want to have a look on:
The engine-neck: http://www.hantsch.co.at/_temp/engine-neck.mp4
The radiator-neck: http://www.hantsch.co.at/_temp/engine-neck.mp4

Now, while everything is taken apart and I have time, I think about improving the engine neck. I think about coating it from inner side with Epoxy resin. As far as I know, Epoxy can permanently resist hot water, so it would at least stop corrosion after soaking into rust and calcium and hardening. From outside, I think about applying 2K liquid metal, let it harden, and then file it into shape.

Good or bad idea?
I would be interested in your opinion.


I also measured the diameter of necks. They are very exactly ø50mm (ø1.96") . My connection hose is sitting very loose on both necks, with radial play of approx. 2mm. This appears to me like a worn out hose. I'd like to know how this hoses sit on your radiator necks. Is it normal that the hose is sitting so loose, or should it need some force to slide onto the necks?

Rainer

I had rust pits on my water outlet too. I filled them with 2K metal epoxy and filed it smooth. I have no leaks.

New or good used radiator hose will normally need to be pushed onto connections. In most all cases, the hose inner diameter will be a little smaller than the outside diameter of the connections. Old hoses often have rust and debris embedded in the rubber, and used rubber has often lost its elasticity and conformability.

Rainer: You wrote " I think about improving the engine neck. I think about coating it from inner side with Epoxy resin. As far as I know, Epoxy can permanently resist hot water, so it would at least stop corrosion after soaking into rust and calcium and hardening. "

I would not use any kind of coating on the interior surfaces because the coatings eventually come loose and cause bigger problems when they clog radiator tubes.

I think your ideas for filling pits on the exterior surfaces are good. If I were faced with this challenge, I would first try non-hardening elastomer seal materials, and if pitting is extreme, consider liberal brazing over the pitted areas of the cast iron fittings and filing down the high spots to improve the hose to metal contact. Respectfully, jb

A little black RTV on the inside of the hose will ensure against leaks even in the presence of rust pits. But the hose should be a snug fit over the neck!

Cylinder head outlets and the inlets are everywhere. Why not find a good one and toss the one with pits?

Here is what I did for the lower radiator connector. The connector had holes as you can see in the first picture. I used a brass plumbing pipe and a lot of solder to seal it in. It doesn't leak at all.
John

Original Smith wrote: ↑

Sun Dec 18, 2022 9:41 pm

Cylinder head outlets and the inlets are everywhere. Why not find a good one and toss the one with pits?

I know that they are available. But they also cost (in Europe, where I am) 40-45 USD, so - as the condition is not so extremely bad - I'll try first with "JB Weld" (an metal-armed Epoxy resin, good for up to 270°C, and water+oil resistant). Lots cheaper and looks very good (I already applied it but it has to harden first.

If this doesn't work (any more), I will need a replacement one, but I am far away from that point at the moment.

NY John T wrote: ↑

Sun Dec 18, 2022 10:03 pm

Here is what I did for the lower radiator connector. The connector had holes as you can see in the first picture. I used a brass plumbing pipe and a lot of solder to seal it in. It doesn't leak at all.
John

John, this is well done.
Luckily my radiator necks are good. Soldering so close to the radiator would make me a little nervous that some other solder joint gets apart. But in your situation there was not much to lose, I guess.

rainer wrote: ↑

Mon Dec 19, 2022 2:49 am

Original Smith wrote: ↑

Sun Dec 18, 2022 9:41 pm

Cylinder head outlets and the inlets are everywhere. Why not find a good one and toss the one with pits?

I know that they are available. But they also cost (in Europe, where I am) 40-45 USD, so - as the condition is not so extremely bad - I'll try first with "JB Weld" (an metal-armed Epoxy resin, good for up to 270°C, and water+oil resistant). Lots cheaper and looks very good (I already applied it but it has to harden first.

If this doesn't work (any more), I will need a replacement one, but I am far away from that point at the moment.

I used JB Weld and never have a leak.

I am one of those nuts that relies pretty heavily on MMO and JB Weld for simple repairs so you may want to dismiss much of my advice. To make a repair to the outside of that piece I would radically wire brush or use electrolysis to remove every bit of rust from the area and the cover the damaged area with a liberal coat of JB Weld. Applying a moderate amount of heat to the part prior to putting the epoxy on will lower the viscosity, allowing it to flow into the pits easily (not too much - you should still be able to hold the part in your bare hand). After it cools and sets up for a few minutes I carefully wrap the repaired area with overlapping bands of masking tape which creates some compression between the part and the epoxy and helps to force the epoxy into the round shape you finally need which eliminates the humps and fills in the hollows making the final shaping much easier. The tape will be a bear to remove but a file or DA sander will do the trick. If any of the epoxy finds its way through a hole in the casting due to the compression I would just wipe it level on the inside and consider it repaired.

Heating the cleaned part prior to applying epoxy will drive off moisture and help the epoxy penetrate and bond to the eroded surfaces. I would use a heat gun or heat lamp and heat the item to about 200 F, then allow it to cool to about 120 F, then apply the epoxy.

browning wrote: ↑

Mon Dec 19, 2022 8:45 am

I am one of those nuts that relies pretty heavily on MMO and JB Weld for simple repairs so you may want to dismiss much of my advice. To make a repair to the outside of that piece I would radically wire brush or use electrolysis to remove every bit of rust from the area and the cover the damaged area with a liberal coat of JB Weld. Applying a moderate amount of heat to the part prior to putting the epoxy on will lower the viscosity, allowing it to flow into the pits easily (not too much - you should still be able to hold the part in your bare hand). After it cools and sets up for a few minutes I carefully wrap the repaired area with overlapping bands of masking tape which creates some compression between the part and the epoxy and helps to force the epoxy into the round shape you finally need which eliminates the humps and fills in the hollows making the final shaping much easier. The tape will be a bear to remove but a file or DA sander will do the trick. If any of the epoxy finds its way through a hole in the casting due to the compression I would just wipe it level on the inside and consider it repaired.

David,

Nothing nutty about JB Weld! As long as it's not used as a miracle cure for every conceivable application. This would be a good application. I have used it for pretty much the same thing in my Model N. So far, so good!

(We won't talk about MMO )

Jerry, If I had it to do over again I would make my kids each take a teaspoon of MMO every morning just to be safe!

browning wrote: ↑

Mon Dec 19, 2022 11:57 am

Jerry, If I had it to do over again I would make my kids each take a teaspoon of MMO every morning just to be safe!

Maybe you've got grandkids???