Ideas to Patch Large Hole in radiator

Dave52

Not sure how this hole got this big. Cast failure?

Possible repairs??

One thought that could be done is braze a patch over the hole. Mild steel has almost same thermal expansion rate as cast iron. Unsure of integrity of cast iron around hole and carbon content in the cast iron radiator.

A lot of work to get it done with many unknowns

PC7060

clean up the surface and surrounding area (1/2”) to bare metal and use JB weld. Wait for it to cure and pressure test.
Good luck!

Dave52

Do not know on what caused the damage. How successful has the JB weld been?

I understand it gets softer when it gets heated. Which is good for expansion.

mattmia2

Is this hot water or steam? Hot water has a lot more pressure and will be more of an issue if it fails.

PC7060

is the hole through the entire jacket into chamber or a tapered hole with small penetration?
The larger the opening the more risk of plug breaking loose as @mattmia2 pointed out in previous post

Dave52

It's one-pipe steam mattmia2

From camera angle zooming in the hole appears to be thru into the chamber, PC7060

mattmia2

If it is steam i bet something is happening that is causing a lot of liquid water to get thrown in there

PC7060

I’d mechanically plug the hole with something like a #6 bolt and two washers such that the washers sandwich the casting. Use brass hardware with the head on the bolt on inside.

The trick will be getting the washer sized such that you can work the bolt head with washer into the slot and then position to hold against the side on the long side of hole.

I’d cut down a fender washer with shears to make an oblong shape that would fit lengthwise to get into position. Then rotate it to lock onto sides and install second washer and nut then tighten.

Additional Tricks & tips: 1) solder the bolt head to the inside washer before inserting. 2) buy longer bolt (1-2”) so you have a way to hold assembly in place as you tighten.

Once you’ve got it nice and tight, cut bolts to size and seal the opening with a 2 part epoxy that can handle steam temperatures.

It’s a make do solution but should hold up.

Let the mockery begin! 😜

PC7060

Follow-up - use stainless steel hardware and secure the inside washer to the head using a nut threaded all the way down. Youll need to make sure the bolt is fully threaded but most that size are.
Probably easier to find SS and simpler than soldering.

Dave52

The radiator with the hole is low priority. Slow process of getting the ideas above implemented. Will post results of what worked when finally done.

guzzinerd

Marine-tex is far superior to JB weld. Having said that, the marine tex didn't hold a similar repair for very long (steam). I ended up cutting out the corroded area and brazed in a new piece. It's been holding for over 2 years now.

Dave52

Went to marine-tex web sight to see specs on this product. It's definitely a different epoxy. Could not find any specs on JB weld to compare.

Was it a large hole and did you use any other material to cove then us epoxy to seal down?

PC7060

Not an advocate on way or other but there’s a high temp version of JB weld.
J-B Weld 37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz
https://a.co/d/43C96FY

Mad Dog_2

Rainbow Rubber with a steel plate. I've only used Marine Tex on waste piping & SS sinks. Don't know how much, I'd trust it on heating. Mad Dog

delcrossv

Try Belzona 1511. Good to 300F. They fix turbines with the stuff. Steel plate to bridge the hole, 1511 to seal everything together.

https://belzona.com/en/products/1000/1511.aspx

Dave52

Belzona, I have worked with this product on shafts with excellent results.

Didn't think of that product for this repair. Looked up the specs. The 1111 seems to fit the repair better. The temperature is low 215deg.