Black iron or Stainless or brass for exhaust??

[romantic comedy]

I have read the threads about using black iron for the hot exhaust. I am redoing the hot exhaust section on my Tartan 34.

I replaced the hot section with black iron from home depot 10 years ago. Now it is time to do it again. It is funny, most of the pipe is very clean on the inside, i can see the seam. The outside is very rusty and it broke at a coupling.

It is not really a hard job, just have to do it. The engine is in the middle of the cabin. I priced out the fittings for the job. I also compared the prices of doing the system in black, brass, and stainless. I got the prices from plumbing supply.com.

Black = $97, brass = $262, stainless = $ 162

The cost for any metal is not that bad. I am wondering if anyone has an opinion about how stainless, type 304, works in the dry exhaust. I was wondering about the longevity of each metal.

I used a 4 inch nipple in the exhaust to connect the black iron to the copper standpipe. The standpipe is made of copper with some type of copper alloy fitting to connect to the dry exhaust. The brass was perfect outside and inside.

Also this exhaust pipe is enclosed in cabinetry so it needs to be heavily insulated. I used a lot of 1/8 X 3 inch fiberglass insulation to cover approximately 4 feet of dry exhaust. I used about 75 feet and it was still hot.

[sailhog]

I'd vote for black iron, if you can find it. I couldn't, so had to go with galvanized steel, which comes with a good bit of off gassing for the first few hours of running.

[hanleyclifford]

10 years for a hot section is outstanding. Black iron is best because it is most like the block (electromagnetically speaking), and cheapest. If you want to spend a little more money, step up to 1 1/2". The manifold exit is that size.

[ArtJ]

I have read the threads about using black iron for the hot exhaust. I am redoing the hot exhaust section on my Tartan 34.

I replaced the hot section with black iron from home depot 10 years ago. Now it is time to do it again. It is funny, most of the pipe is very clean on the inside, i can see the seam. The outside is very rusty and it broke at a coupling.

It is not really a hard job, just have to do it. The engine is in the middle of the cabin. I priced out the fittings for the job. I also compared the prices of doing the system in black, brass, and stainless. I got the prices from plumbing supply.com.

Black = $97, brass = $262, stainless = $ 162

The cost for any metal is not that bad. I am wondering if anyone has an opinion about how stainless, type 304, works in the dry exhaust. I was wondering about the longevity of each metal.

I used a 4 inch nipple in the exhaust to connect the black iron to the copper standpipe. The standpipe is made of copper with some type of copper alloy fitting to connect to the dry exhaust. The brass was perfect outside and inside.

Also this exhaust pipe is enclosed in cabinetry so it needs to be heavily insulated. I used a lot of 1/8 X 3 inch fiberglass insulation to cover approximately 4 feet of dry exhaust. I used about 75 feet and it was still hot.

I have a Tartan 34C also. About 10 years ago I rebuilt the exhaust with
black iron and also had the bronze standpipe cleaned out. It required a lot
of exhaust wrap and a change of the T at the upward bend to a elbow in
order to keep it away from the plywood plenum. I also wired some
galvanized stove pipe to the upward bend as a safety precaution.
Other than watching the heat,especially at the upward elbow, it has
been trouble free.
Moyer sells a replacement standpipe if you need one. The bronze has
served me well.
Tom Stevens of Indigo also has a Tartan 34C . A few years ago he
replaced the standpipe with a water lift muffler and led the exhaust to
the rear of the boat. You might want to touch base with Tom as well
Best Regards

Art

[romantic comedy]

Hanley, my manifold flange hole is inch and a quarter. So is the MMI flange. Did you machine yours to a bigger size? My standpipe is inch and a quarter and I am not going to modify that. I find different reports on black iron. Some say that it is just the same as galvanized pipe. It seems that way to me.

Sailhog, I cant find any black iron locally, but I can order it. The local plumbing supply can get it in a day. Plumbing supply .com has a lot of black iron, brass and ss listed. That is where I priced out the pipe.

Art, I still have the original standpipe in very good condition. I can even read the revere markings. I have used four 45 degree elbows to make the exhaust. I dont want to use a 90. I dont here the other t 34 guys complaining about the exhaust getting hot. I dont know why, maybe they dont run far. It has been a pin on long motoring trips. I have had to open the engine box and use fans to keep it cool. Aside from a water jacketed exhaust I have thought about wrapping soft copper around the insulated pipe and water cooling it. I have FWC also. Mostly, I guess, I need to improve the air flow. The way it is set up is a pain. The blower is not meant to be used as a fan. I have a few new ideas I am working on. Also the exhaust is mounted rigid. I am working on mounting it flexible to accept some movement. I am surprised that we dont have trouble with the stresses of movement. I guess that shows how smooth the Atomic four is!

I know Tom. We had some good conversations a while ago. I ran the ICW with his prop. I thought about a waterlift to give my more room at the nav station. I got used to working around the standpipe, plus it is a great exhaust.

I am still wondering about brass or stainless steel.

Thanks guys.

[Ajax]

Black iron, and paint it with high-temp POR-15. That'll keep the outside from rusting.

[hanleyclifford]

Hanley, my manifold flange hole is inch and a quarter. So is the MMI flange. Did you machine yours to a bigger size? My standpipe is inch and a quarter and I am not going to modify that. I find different reports on black iron. Some say that it is just the same as galvanized pipe.

The flange is 1 1/4" but the hole in the manifold is 1 1/2" so I opened the flange (my own homemade) to 1 1/2" - bought the tap just for the job - got a huge benefit. Black iron is your best choice. Galvanized may look better at first but there is a reason they call it "galvanized" as in "galvanic cell". In the presence of salt water the black does better and you won't have to snort it.

[ArtJ]

Hanley, my manifold flange hole is inch and a quarter. So is the MMI flange. Did you machine yours to a bigger size? My standpipe is inch and a quarter and I am not going to modify that. I find different reports on black iron. Some say that it is just the same as galvanized pipe. It seems that way to me.

Sailhog, I cant find any black iron locally, but I can order it. The local plumbing supply can get it in a day. Plumbing supply .com has a lot of black iron, brass and ss listed. That is where I priced out the pipe.

Art, I still have the original standpipe in very good condition. I can even read the revere markings. I have used four 45 degree elbows to make the exhaust. I dont want to use a 90. I dont here the other t 34 guys complaining about the exhaust getting hot. I dont know why, maybe they dont run far. It has been a pin on long motoring trips. I have had to open the engine box and use fans to keep it cool. Aside from a water jacketed exhaust I have thought about wrapping soft copper around the insulated pipe and water cooling it. I have FWC also. Mostly, I guess, I need to improve the air flow. The way it is set up is a pain. The blower is not meant to be used as a fan. I have a few new ideas I am working on. Also the exhaust is mounted rigid. I am working on mounting it flexible to accept some movement. I am surprised that we dont have trouble with the stresses of movement. I guess that shows how smooth the Atomic four is!

I know Tom. We had some good conversations a while ago. I ran the ICW with his prop. I thought about a waterlift to give my more room at the nav station. I got used to working around the standpipe, plus it is a great exhaust.

I am still wondering about brass or stainless steel.

Thanks guys.

How did you get around the 90 degree elbow at the bottom of the standpipe? Did you cut
away some of the Plywood cover?

With Regard to others need noticing the heat. The original way the exhaust was covered with Asbestos Plaster
I have noticed in another recent thread some talking about some navy pipe plaster. Maybe they are using one
of these. I have to lift the cover and run the blower all the tiime on a trip

[romantic comedy]

Art, I guess you mean the 90 near the floor. I will try to find some pictures and post them, if I have any. I will take pictures of the new exhaust too.

Thanks for saying that you have to open the box. I have known a bunch of t34 owners and no one has said this before.

I also read that post about the plaster. I think it is a navy thing. I have not seen a plaster covered exhaust, but would like to find out about it.

[ArtJ]

Correct
I do mean the 90 degrees near the floor. That one is most susceptible
to scorching the plywood. I think originally the asbestos plaster offered some protection.

Art

By the way, my Engine has the PTO pulley on the front for the salt water pump. I cut out and extended with a
teak bevel the area around the pulley to prevent the engine cover box from occasionally hitting it.

[romantic comedy]

Art, I have my Hi output alternator running off the PTO, mounted to the bulkhead. I did not have a clearance issue, but it is close. I have the sea water pump mounted in place of the original alternator running off the accessory drive.

I mainly have problems with the vertical cabinetry getting hot. That aft end of the settee, where the batteries were placed. (I have a large heat exchanger in there now.)

[ArtJ]

Where have you moved the batteries to?
I have 4 batteries in there which
contribute to a port list.

[rrranch]

The insulation on mine was just fiberglass plaster looking stuff. It looks the same as asbestos but it's not. I'm not sure how really to tell the difference in the two. I've handled so much of both I can tell by looking but beware of that stuff if you think it's asbestos. We called it lagging in the navy. No one sells it commercially that I can find but it is a lot better stuff than fiberglass wrap for keeping the heat in.

[romantic comedy]

Art, I have the house batteries under the companionway. I had two west marine 6 volts there for a few years. They were L 16, I think, only lasted a few years. Now I have 2 trojan t 105 6 volt batts there. I have 1 12 volt group 24 in the original location, as a start battery.

I put two heafty cross members to support the batteries under the companion way. I even made a heavy plywood box for them. After the L 16 batteries went, I just made a platform to tie the new trojans to.