No more black iron?

[joe_db]

My exhaust popped a leak and I thought it would be a trivial repair, run down to the store and buy some pipe.
Turned out to not be so easy, none of the local hardware stores, Home Depot, or Lowes carry black iron in 1-1/4" any more
I guess I need to pay the $$$ to have it shipped from McMaster.

[edwardc]

Joe,

I've found that, because we of the Chesapeake are so close to McMaster (New Jersey), that even ordering the cheapest ground shipping they have, it usually arrives in one day.

I would also recommend considering using stainless. Its much more expensive than black iron, but I feel it is worth the extra expense. Cry once. I did mine in all stainless over 10 years ago, and so far the only piece that has failed is the steel adapter flange on the manifold. Back when I did it, it cost me around $200 for all the pipe and fittings.

[joe_db]

Originally Posted by edwardc

Joe,

I've found that, because we of the Chesapeake are so close to McMaster (New Jersey), that even ordering the cheapest ground shipping they have, it usually arrives in one day.

I would also recommend considering using stainless. Its much more expensive than black iron, but I feel it is worth the extra expense. Cry once. I did mine in all stainless over 10 years ago, and so far the only piece that has failed is the steel adapter flange on the manifold. Back when I did it, it cost me around $200 for all the pipe and fittings.

More than double that now
Note sure how the flange failed, that part is dry. The only reason I don't reuse them is I can never get the old one off the pipe.

[Easy Rider]

It might not work in other areas but I've found by taking the old worn black parts to the plumbing wholesaler they will have gathered all the parts for me in minutes. I do try to not go at busy times and I stay out of the way of tradesmen whose time means money. Works for me.

[joe_db]

Originally Posted by Easy Rider

It might not work in other areas but I've found by taking the old worn black parts to the plumbing wholesaler they will have gathered all the parts for me in minutes. I do try to not go at busy times and I stay out of the way of tradesmen whose time means money. Works for me.

UPS will have it on my porch tomorrow if all goes well.

[edwardc]

Originally Posted by joe_db

More than double that now
Note sure how the flange failed, that part is dry. The only reason I don't reuse them is I can never get the old one off the pipe.

Heat + iron + oxygen = rust. The rust takes up more space than the iron and locks the pipe into the flange. In my case, after 10 years, the force was so great that it split the flange!

[joe_db]

Originally Posted by edwardc

Heat + iron + oxygen = rust. The rust takes up more space than the iron and locks the pipe into the flange. In my case, after 10 years, the force was so great that it split the flange!

Wow!

[Sam]

Joe - sent you private message, thx

[joe_db]

I don't see one???

[Mo]

I'd go SS and do it. The quality of black iron is not what it was. My first change lasted 6 years, the second 5 years and I'm into the 4th year on this current one. I am buying SS pipe and doing it next time. I'd also thought of SS exhaust pipe with a welded SS flange but I don't think it's up to it. The pipe is so thin it won't last. I just may gather up my parts this winter and do it as it was in the back of my mind this year.

[sastanley]

Originally Posted by joe_db

More than double that now
Note sure how the flange failed, that part is dry. The only reason I don't reuse them is I can never get the old one off the pipe.

I have a broken hot stack with both flange and mixer ready for the next owner to pick up. I never took the time to cut the broken pipe off. I figured if you have one of each you have 5 years or so to worry about it. I think this is year three.

[joe_db]

The pipe fittings from McMaster are USA made and seem better than the Home Depot Chinese stuff. For the T at the top I got a fitting with 2 1-1/4" ports and a 3/4" on the top, it saves me a reducer for the water injection.
I forgot how much I hate clocking these fittings. OK, a little loose, do I dare go for one more turn or will it jam up halfway around?
I swear the next time I make one of these I will try and get some stainless fabricated or weld it together or something.

[Dave Neptune]

Joe, the other big plus with black iron is not needing to use any sealant of any kind. If you just get it snug or even a tiny bit loose it will "rust" sealed and "fixed" in position in a few run cycles. The last one I built in Volador I actually used wire to hold in place as getting that extra turn was not possible. It sealed fine and was still functioning when I sold the boat.

Dave Neptune

[joe_db]

Originally Posted by Dave Neptune

Joe, the other big plus with black iron is not needing to use any sealant of any kind. If you just get it snug or even a tiny bit loose it will "rust" sealed and "fixed" in position in a few run cycles. The last one I built in Volador I actually used wire to hold in place as getting that extra turn was not possible. It sealed fine and was still functioning when I sold the boat.

Dave Neptune

Yup, the old one is not coming apart short of dynamite.

[Dave Neptune]

I have heard from a few old timers that cleaning the oil off of the pipe and then assembling with really salty water speeds things up. I never have tried it but it "sounds" like a good idea.

Dave Neptune

[hanleyclifford]

The problem with using stainless steel for exhaust is that it sets up a galvanic cell with it being the cathode (more noble) and the first piece of steel or cast iron going to the manifold becoming the anode (less noble) - hence the failure of the steel adapter. Be happy it was just the adapter which is easily replaced. I would still be worried about mixing metals in the presence of salt water which is always being injected into the system.

[joe_db]

I was wondering about that. What if you put a zinc on there somehow?
Meanwhile, I think I'll make another exhaust and swap them out 3-4 years from now instead of waiting for it to leak again. I am a bit frustrated that the original iron exhaust lasted over a decade, they seem to keep getting worse and worse.

[sastanley]

Slightly unrelated, I rebuilt the support structure for the swim platform on my powerboat, which is built out of the same SS pipe as a bimini is made of. I put a zinc on each leg that goes underwater and connects to the bronze fitting bolted to the hull.

[ndutton]

Well done Shawn. The key component = being immersed in an electrolyte.

[Mo]

Originally Posted by sastanley

Slightly unrelated, I rebuilt the support structure for the swim platform on my powerboat, which is built out of the same SS pipe as a bimini is made of. I put a zinc on each leg that goes underwater and connects to the bronze fitting bolted to the hull.

I see your boat Shawn and the name...well I think of "Dock Holiday"...no disrepect intended being on a dock, but it has a ring to it.

[sastanley]

Originally Posted by ndutton

Well done Shawn. The key component = being immersed in an electrolyte.

Neil, When we bought this boat in July 2022, and then hauled it in Dec 2022, there were no zincs left anywhere on the boat, except some small nodules on the trim tabs. There had been two on each prop shaft, a pancake on each rudder, and a pancake on each trim tab.
I asked the previous owner how often he replaced the zincs..
His response.. "When did you buy the boat..July??? That is about the time I would get my dive gear on and put new zincs on everything after launching in March".

I said, "OK, thanks for the info", thinking he just thought that was normal and was putting band aids on a problem. I know more zincs are NOT the permanent answer if he was rolling thru them from March to July, and there is more at play. However, those zincs on the swim platform I can see from the dock, so I have a little piece of mind...however, they are not bonded to other parts of the boat. (as far as I know, nothing on this boat is bonded...that is an entirely different discussion. ) I do not know if the previous owner shore power was suspect, etc. etc. blah blah blah...but I will get to the bottom of it. I need to short haul here at the end of the season for some answers. The boat is in a different location, different shore power, (I do not always have the boat plugged in), all that stuff.

Sorry for the hijack.

Originally Posted by Mo

I see your boat Shawn and the name...well I think of "Dock Holiday"...no disrepect intended being on a dock, but it has a ring to it.

Ha...none taken Mo! We are still looking for a boat name. This is the last picture I remembered to take as I was grinding the transom off. Y'all got to see the cart before the horse in this thread.