Heat exchanger crack

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

drexmac

Newbie
Joined
Jan 15, 2023
Messages
4
Vessel Name
Sandpiper
Vessel Make
Californian 34
I have a Kubota phaser 6500 generator that has a crack on the heat exchanger / manifold. Apparently, it was not winterized correctly. It's cast iron, so weld repair is tricky. Before I remove it and start trying to find a welder who will take on the task, I was wondering if anyone has experienced a similar issue ? Am I able to seal it with something, like JB weld, gasket maker, etc?
 

Attachments

  • IMG_20240531_121130272_HDR.jpg
    IMG_20240531_121130272_HDR.jpg
    96.4 KB · Views: 77
  • IMG_20240531_121133680_HDR.jpg
    IMG_20240531_121133680_HDR.jpg
    100 KB · Views: 75
  • IMG_20240531_121116570_HDR.jpg
    IMG_20240531_121116570_HDR.jpg
    83.3 KB · Views: 70
  • IMG_20240531_121119309_HDR.jpg
    IMG_20240531_121119309_HDR.jpg
    72.1 KB · Views: 66
  • IMG_20240531_121640549.jpg
    IMG_20240531_121640549.jpg
    65.6 KB · Views: 65
  • IMG_20240531_121143500.jpg
    IMG_20240531_121143500.jpg
    94.8 KB · Views: 74
Ouch. I suspect JB Weld or similar won't last, and that welding or replacement is the best route. Is Phasor still in business? It might be worth a call to see if a replacement is available and what the cost would be. Probably crazy expensive, if even available, but worth knowing your options, I think.
 
No epoxy or brazing will last. Only welding.
If just the water is leaking, not the exhaust, you could continue to use the manifold and add a universal HE.
To weld the crack needs to free of rust and oil. Drill a hole at each end of the crack to relieve stress. Some like to drill the hole about 1/8" from the end of the crack.A welding shop that routinely does cast iron will have an oven for preheating. For best results the entire HE should be heated to 650°F. If using a torch, use a heat gun to measure temps and keep them even. You can us a kitchen oven to get close and finish heating with a torch. If welding requires several passes, the prior pass must be cooler than 1200°F. Between passes the metal away from the weld area may need reheating to keep temps as uniform as possible. Too much temp diff across the HE may cause cracks. Iron doesn't expand and contract like steel. After welding cool slowly. I use to use an asbestos blanket to wrap cast iron. A large bucket of sand works. What works good is as soon as welding is done put the HE in an oven at max temp and lower 50° every hour.
Weld material is usually nickel. Rod and wire comes 50% to99% nickel. Its' better to spring for the highest nickel.
There are several companies that make replacement heat exchangers. One may make your exact exchanger, others have universal HE that may require modifying your plumbing. Some companies to check out: Orca Marine Cooling Systems
 

Attachments

  • Barr.JPG
    Barr.JPG
    78.5 KB · Views: 14
  • marine exhaust.jpg
    marine exhaust.jpg
    98 KB · Views: 11
I have a Kubota phaser 6500 generator that has a crack on the heat exchanger / manifold. Apparently, it was not winterized correctly. It's cast iron, so weld repair is tricky. Before I remove it and start trying to find a welder who will take on the task, I was wondering if anyone has experienced a similar issue ? Am I able to seal it with something, like JB weld, gasket maker, etc?
where are you located?
 
might be cheaper to get a new one from Phaser?
 
Kemah, TX... South of Houston
I am in Seattle area. you might try taking it to a radiator repair shop that specializes in marine heat exchangers. we have one here called Seattle radiator that could fix this as that is what they do.
 
I have a Kubota phaser 6500 generator that has a crack on the heat exchanger / manifold. Apparently, it was not winterized correctly. It's cast iron, so weld repair is tricky. Before I remove it and start trying to find a welder who will take on the task, I was wondering if anyone has experienced a similar issue ? Am I able to seal it with something, like JB weld, gasket maker, etc?
I had the exact same issue on a Kubota running a 21kw Phasor. Not a winterizing issue because I’m in Florida. It didn’t last 300 hours!
 
Ditto what Lepke said, highest nickel content available, grind a 90 degree vee between drilled holes, clean the loose carbon in the vee with acetone throughly, peen the nickel weld, and cool slowly.
 
I have a Kubota phaser 6500 generator that has a crack on the heat exchanger / manifold. Apparently, it was not winterized correctly. It's cast iron, so weld repair is tricky. Before I remove it and start trying to find a welder who will take on the task, I was wondering if anyone has experienced a similar issue ? Am I able to seal it with something, like JB weld, gasket maker, etc?
Does anyone know if green or red coolant makes a difference in the longevity of a heat exchanger like this?
 

Latest posts

Back
Top Bottom