View Full Version : Cast iron exhaust
JEREMY79
06-13-2006, 10:42 PM
Tonight I found that one of my manifolds is cracked along the seam. It could have happened when the engine froze but I dont think so. Anyway my question is can you weld these? Or will I have to replace them.
Jeremy
How long is the crack? If it's a short one, grind a V into it and fill it with Marine Tex. It's hard to weld cast iron without having it change shape. An exhaust manifold doesn't have high pressure in it, so if the crack is in the water jacket, you should be OK.
JEREMY79
06-13-2006, 11:02 PM
JimN, I was hoping you were around. What is Marine Tex? and where can I get it
Mag_Red
06-13-2006, 11:07 PM
JimN, I was hoping you were around. What is Marine Tex? and where can I get it
I'm sure Eric can track some down for you for the right price ;)
Mag_Red
06-13-2006, 11:09 PM
Or you could click this link (http://www.jamestowndistributors.com/userportal/search.do?freeText=marine%20tex&page=GRID&history=&engine=adwords!6456&keyword=%28marine+tex%29&match_type=) for free :D
dichdoc
06-13-2006, 11:31 PM
The only luck I've had welding cast is with "Super 600" rod its pricey but seems to work good. Still could have some porosity issues which could be weak and leak. With that said I personally would replace it rather than weld it just for my piece of mind. TB
West Marine and a lot of other stores have it. There's probably a boat dealer near you that sells it.
DemolitionMan
06-23-2006, 10:22 PM
go to skidim.com which is discount inboard marine and they will have a new one.
DemolitionMan
06-23-2006, 10:25 PM
My manifold cracked where it bolts into the head at.
kalanic
06-24-2006, 09:44 AM
Welding cast iron is not easy & not recomended! I would use the Marine Tex as well or Belzona. We have done repairs to the bodies of cast iron valves here in the refineries & have had some success but you must pre heat the repair area first. Porosity is always a problem with cast iron wedling & if cooled to rapidly, will cause more cracking.
Sodar
06-24-2006, 02:18 PM
Has anyone ever replaced their cast iron exhaust with the new ETX exhaust that is advertised in WaterSki? I was just curious if you could upgrade to it, or if you can only buy it with a new boat...
east tx skier
06-24-2006, 03:04 PM
If you have a chevy (which you do), you can upgrade. But it's spendy. I think there are cheaper ways to achieve horsepower.
Jim@BAWS
06-24-2006, 03:24 PM
Normally you would want to replace them.
Clean the area real good with an ACID base. Grind Clean
JB WELD BROTHER....JB WELD not the fast cure stuff!!
Jim@BAWS
Cloaked
06-24-2006, 04:12 PM
Normally you would want to replace them.
Clean the area real good with an ACID base. Grind Clean
JB WELD BROTHER....JB WELD not the fast cure stuff!!
Jim@BAWSI trusted you fully until this..... :( :( ;)
Cast can be welded as pointed out. With the proper joint prep, compatible filler metal, and temp control (easily enough with a temp gauge or temp stick and a rose bud for pre-heat and post-heat or actually cool-down treatment) you can get a successful repair. I have had it done to two different mainfolds (luckily successful). If the root pass goes in (which it should very well with a skilled welder), the intermittent pass (if there is one depending on the size of the area) will coerce right nicely on top of it. The surface pass is what may develop porosity, but that being said, it's porosity on the surface. A welder shoud be able to easily grind that out back to clean metal and fill it back in. Then a leak test can be done to ensure the weld's integrity. Simple enough...fill it with water and see if it leaks (overnight for a saturation time).
But honestly, on my preference for the long run, for no more than a manifold costs, I'd order one up and bolt on a new one.
Jim@BAWS
06-24-2006, 10:32 PM
SPORTY C'mon give me a break here. I have done it in a pinch
but would not recommend as a permanant fix.
If I was to recommend a permanent fix it would be DUCK TAPE
The Handy Man's Secret Weapon :uglyhamme
Jim@BAWS
I trusted you fully until this..... :( :( ;)
Cast can be welded as pointed out. With the proper joint prep, compatible filler metal, and temp control (easily enough with a temp gauge or temp stick and a rose bud for pre-heat and post-heat or actually cool-down treatment) you can get a successful repair. I have had it done to two different mainfolds (luckily successful). If the root pass goes in (which it should very well with a skilled welder), the intermittent pass (if there is one depending on the size of the area) will coerce right nicely on top of it. The surface pass is what may develop porosity, but that being said, it's porosity on the surface. A welder shoud be able to easily grind that out back to clean metal and fill it back in. Then a leak test can be done to ensure the weld's integrity. Simple enough...fill it with water and see if it leaks (overnight for a saturation time).
But honestly, on my preference for the long run, for no more than a manifold costs, I'd order one up and bolt on a new one.
ski_king
06-24-2006, 11:05 PM
SPORTY C'mon give me a break here. I have done it in a pinch
but would not recommend as a permanant fix.
If I was to recommend a permanent fix it would be DUCK TAPE
The Handy Man's Secret Weapon :uglyhamme
Jim@BAWS
You can say that again......
Duck Tape and WD40 can fix almost anything,
If duck tape and WD40 can't fix it, 303 can!
bcampbe7
06-24-2006, 11:07 PM
You can say that again......
;)
...........................
Hoosier Bob
06-24-2006, 11:33 PM
I have used the old JB a few times and it has never let me down! In the desert throw a chain, JB. I would think it would hold any exhaust manifold if prepped correctly. Sure you can weld it but why? Grind and JB and when you come into some do re mi buy a new one! :D