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24-06-2010, 23:06
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#16
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Registered User
Join Date: Jun 2010
Boat: Far East Mariner 40
Posts: 303
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I'm wondering why everyone else besides me is saying the manifold is cracked when Geoff never said that. He said it has a leak. If it has burned through due to a defect in the cast iron or because of a design flaw, a satisfactory permanant repair can be made using brazing material by anyone with any skill at welding and brazing with a torch. The bronze alloy is not as strong as cast iron, but doesn't need to be for this purpose. Once the area is thoroughly cleaned and heated to the right temperature and the flux does it's job the material flows in and bonds very well. I'd grind a little beyond the leak and put in a little extra material around the leak just for more adhesion surface to the repair. I'm not saying that this is better than buying a new manifold, just that it would probably work. You'd still want to keep your eye on it, though.
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I do all my own stunts.
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25-06-2010, 03:48
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#17
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Registered User
Join Date: Jun 2007
Posts: 853
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Paradix's post #12 has the correct method.
Here is a good link Guidelines for Welding Cast Iron | Lincoln Electric
Have repaired a few cast iron articles in places where there was no alternative.
In the southern hemisphere, barbecues and braais are usually big enough to take a cast iron manifold, #1: get a good charcoal fire going, once it settles , add the manifold with part requiring repair in suitable position and using the correct electrode rods, weld/repair the leak or crack - less than an inch at a time. Once done, with DRY sand cover the manifold and coals completely. Leave for at least 4 hours. Grind off excess weld material.
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25-06-2010, 05:11
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#18
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Registered User
Join Date: Jan 2010
Location: Port Ludlow Wa
Boat: Makela,Ingrid38,Idora
Posts: 2,050
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My Dad has Lehman engines in his Alaskan. He has the exact problem you have. His manifolds have been welded every three to five years. It's a design flaw that simply must be looked after on a regular basis. Welding? Yes but inspect often.
Todd
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25-06-2010, 06:32
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#19
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Registered User
Join Date: Oct 2009
Location: CLOD in OH
Posts: 257
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Take a grinding wheel (a dremel tool will work in a pinch) and grind the crack out to a V. Make sure you are down to bright metal (no contaminates). Fill crack with JB weld. Very easy to do and the success rate is very high.
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25-06-2010, 06:39
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#20
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Registered User
Join Date: Oct 2009
Location: CLOD in OH
Posts: 257
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Was not aware of design flaws in the manifold, mine have over 20,000 hrs on them , 9,000 put on by me. no issues with cracks or holes.
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27-06-2010, 14:50
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#21
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Registered User
Join Date: May 2008
Location: mexico
Boat: 75' steel sutton ketch,Warwick 70' aluminum sloop
Posts: 127
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cast iron welding
Hey Geoff-- Hear from Bob and Don that your a little warm down there!! About the welds--- Ive' done it on my manifolds (different Fords) a few times and it works fine. Just make sure to pre heat the manifold, use cast rod and only weld about the size of a dime at a time at around 90 amps. Hit it with a ball peen hammer while cooling to push the crack as far as it needs to be solid. Don't weld any more until it's cool to your hand then start over. It's always worked for me. You can braze it but you'll be doing it over again sooner or later and JB weld for temp period also. lots of patience!! Good luck--say hi for me to the crew!! John
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27-06-2010, 15:42
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#22
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Registered User
Join Date: Sep 2009
Posts: 5
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Another option - have someone fabricate a new manifold from exhaust tubing (or stainless, etc.)
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29-06-2010, 15:11
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#23
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Registered User
Join Date: Oct 2009
Location: Los Angeles, CA
Boat: Catalina 42 MK I
Posts: 203
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Thanks everyone, and hi John!!! Yes, very hot here, shouldn't be any trouble at all to "preheat" the manifold as there's nothing here that isn't plenty hot already. (weak attempt at humor.) Going to pull manifold off tomorrow early morning before it gets too hot. I've been directed to a "master" welder down here and I might as well try to repair this one since so many of you think it's at least worth trying. Will get to see if it works before i get too far away from possibility of ordering a new one. $2500!!!!! Ouch. But I think it comes with paint so not really that bad I guess.
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29-06-2010, 17:25
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#24
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Eternal Member
Join Date: Feb 2008
Location: Las Brisas Panama AGAIN!
Boat: Simpson, Catamaran, 46ft. IMAGINE
Posts: 4,507
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Quote:
Originally Posted by vintageray
I recommend brazing it with a torch and flux coated brazing rod. Make sure to clean thoroughly all carbon, oil etc first. This makes a very satisfactory repair if done properly.
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Bingo,
I've been in the business for 33 years. One of my workmates did this to his manifold, and it lasted for over a decade I know of. We used the same method splitting 6 cylinder manifolds to do old style twice pipes ...... i2f
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29-06-2010, 18:27
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#25
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Registered User
Join Date: Oct 2009
Location: Los Angeles, CA
Boat: Catalina 42 MK I
Posts: 203
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vintage,
thanks again for weighing in. i really value it. so, for the about to know too much, flux coated brazing rod and cast rod are two different ways to go; the first is bronze alloy, and the second is welding with cast iron, which i'm gathering is very difficult to do because of the temp issues/cooling issues. Is prep the same, i.e. for both i still have to clean area super well? does this mean sand blasting, or....?
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29-06-2010, 18:42
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#26
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Registered User
Join Date: Oct 2009
Location: Los Angeles, CA
Boat: Catalina 42 MK I
Posts: 203
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... and to clarify; I have taken a mirror and light to the area and can see the "leak". It appears almost as though an earlier corrosion on the underside surface went unattended and unpainted (really hard to see under there - i swear the rest of the engine looks great) and when i started to see smoke from there i located the bubbled or corroded metal area and scraped it with a screwdriver and sure enough, a pretty good sized hole/crack was definitely there with a lot of tell-tale carbon around it. And no water leak, just smoke. The hole is about 1/2 in long by 1/16 wide. I'll be able to report more when I pull the damned thing off and can really see it.
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29-06-2010, 18:42
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#27
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Registered User
Join Date: Jun 2007
Posts: 853
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Quote:
Originally Posted by Geoff H.
for both i still have to clean area super well? does this mean sand blasting, or....?
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If the area to be repaired is relatively small use a steel wire brush - no need for sand blasting.
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30-06-2010, 19:42
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#28
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Registered User
Join Date: Oct 2009
Location: Los Angeles, CA
Boat: Catalina 42 MK I
Posts: 203
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Update: Pulled the devil off, not good. The whole last 'section' or well, not sure what to call it, is bad. The little hole, with the pressure of my finger, turned into a really big hole. Looks like corrosion over a long long time -- flaky rust, like a layered biscuit, and it's all bad. Have very little faith that welding, no matter how good the guy is, is going to fix this. I'll take it to be looked at tomorrow, but I'm thinking I'm going to be shipping one into Mexico.
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03-07-2010, 16:36
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#29
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Registered User
Join Date: Oct 2009
Location: Los Angeles, CA
Boat: Catalina 42 MK I
Posts: 203
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Further Update:Even the welder said no, can't be fixed. He suggested I let him make me a new one. Hmmm.
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03-07-2010, 16:54
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#30
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Registered User
Join Date: May 2009
Location: Panama
Boat: Steel trawler 63' Eileen Farrell
Posts: 961
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Have him make you two.
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