What material provides the most longevity? I replaced the mixing elbow on my little Yanmar last year due to failure. It seems that the previous owner had created one from screwed carbon steel pipe and fittings and had a 1/2" stem welded into it to accomodate the water discharge into the exhaust. I have no idea how old it was when it failed, (fell apart in my hand with a little wiggle-jiggle-shake). I replaced it in the same configuration with threaded 314 stainless fittings and hose barbs that were seal welded and am wondering if the stainless was a good choice for this salt water percolator....any thoughts? What is the 'normal' life of a mixing elbow? A fellow sailor recently cut short his weekend trip when his mixing elbow failed. He said that it didn't 'look' bad, but had corroded from the inside out until it sprang a leak on the weekend trip.
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Dale, are you saying you built your own elbow?
Most everyone buys them from Yanmar. Can you post a Pic? I'm on my third. This time I had it ceramic coated by JetHot. Maybe this one will last longer than six years in salt. The last exhaust stuff I had to build was on my Ericson. They don't make them like that anymore. :{
Most everyone buys them from Yanmar. Can you post a Pic? I'm on my third. This time I had it ceramic coated by JetHot. Maybe this one will last longer than six years in salt. The last exhaust stuff I had to build was on my Ericson. They don't make them like that anymore. :{
Cast Iron.
Dale: The OEM units are cast iron. They only cost about $100. They should last for 5 or more years. This is a maintenance item that should be replaced every 5 or so years if you are in salt water. I think they will last forever in fresh water.
Dale: The OEM units are cast iron. They only cost about $100. They should last for 5 or more years. This is a maintenance item that should be replaced every 5 or so years if you are in salt water. I think they will last forever in fresh water.
Black iron
Not the mixing elbow but the next one down failed on me last year. I was going to replace the entire system with sainless, but a friend who works in metals said that the cold water hitting the hot stainless could cause it to crack and then fail. So i just replaced it with black iron pipe fittings, I now carry some spare pipe and fittings just in case ( cheaper than stainless). The engine is a 1987 Universal and next fall i will replce the entire exhaust system with black iron pie and fittings and that should last for another 17 years, and hopefully i should too.
Not the mixing elbow but the next one down failed on me last year. I was going to replace the entire system with sainless, but a friend who works in metals said that the cold water hitting the hot stainless could cause it to crack and then fail. So i just replaced it with black iron pipe fittings, I now carry some spare pipe and fittings just in case ( cheaper than stainless). The engine is a 1987 Universal and next fall i will replce the entire exhaust system with black iron pie and fittings and that should last for another 17 years, and hopefully i should too.
Exhaust Riser Material
Dale The old Catalina's had black iron. I wrote an article with pictures of my replacement that was published in the C34 tech Notes section of Mainsheet magazine, Feb. 2004. The link is to the C34 website message board with lots of discussion. The new material provided by Catalina is stainless. My first black iron one went for 1390 engine hours, to last August 2003 in a 1986 boat. It's not the age of the boat, it's the engine hours. Also try: http://www.c34.org/projects/projects-exhaust.html Stu
Dale The old Catalina's had black iron. I wrote an article with pictures of my replacement that was published in the C34 tech Notes section of Mainsheet magazine, Feb. 2004. The link is to the C34 website message board with lots of discussion. The new material provided by Catalina is stainless. My first black iron one went for 1390 engine hours, to last August 2003 in a 1986 boat. It's not the age of the boat, it's the engine hours. Also try: http://www.c34.org/projects/projects-exhaust.html Stu
Fred, A picture MAY be worth more than words..
...But it would likely be different for each application. It has been a year since the project and I forget whether it was 1 1/2" or 1 1/4" pipe,etc. Mine consists of five 10"+/- long threaded nipples, four 90's, one 1 1/4" hose barb, and a 1/2"x4" long nipple (all were stainless)....configured roughly into a ( -/-_,,, )...which means: over, up, over, down, and out thru the hose barb....respectively. The beauty of the threaded approach was that I could get the bends appropriate for discharge to the hose/wet muffler and then get it welded as necessary. As far as the insertion of the 1/2" water feeder goes, it was nothing for the welding shop to locate and punch a hole in the 'down' section and weld in the nipple such that no water could back-feed into the manifold. The first threaded section of this affair simply threaded into the original yanmar cast piece that bolts up to the manifold. Stu, its interesting that Cat has gone this route....seems to answer my question of whether my choice of stainless was a good one or not. I've wrapped the first section with hi-temp insulation and what remains exposed is just warm to the touch....and its working well so far. The cost, as I remember, was around $125-150, plus welding....and parts were available at pipe suppliers and/or hydraulic hose shops....just make sure the I.D/O.D. of pipes vs. hoses work before welding it up. Thanks for the input, all.
...But it would likely be different for each application. It has been a year since the project and I forget whether it was 1 1/2" or 1 1/4" pipe,etc. Mine consists of five 10"+/- long threaded nipples, four 90's, one 1 1/4" hose barb, and a 1/2"x4" long nipple (all were stainless)....configured roughly into a ( -/-_,,, )...which means: over, up, over, down, and out thru the hose barb....respectively. The beauty of the threaded approach was that I could get the bends appropriate for discharge to the hose/wet muffler and then get it welded as necessary. As far as the insertion of the 1/2" water feeder goes, it was nothing for the welding shop to locate and punch a hole in the 'down' section and weld in the nipple such that no water could back-feed into the manifold. The first threaded section of this affair simply threaded into the original yanmar cast piece that bolts up to the manifold. Stu, its interesting that Cat has gone this route....seems to answer my question of whether my choice of stainless was a good one or not. I've wrapped the first section with hi-temp insulation and what remains exposed is just warm to the touch....and its working well so far. The cost, as I remember, was around $125-150, plus welding....and parts were available at pipe suppliers and/or hydraulic hose shops....just make sure the I.D/O.D. of pipes vs. hoses work before welding it up. Thanks for the input, all.
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