ONAN MDKD 8KW Generator
The generator had enough going on to warrant its own dedicated post.
Unlike sailboats most motor yachts have a generator of some sort. Motor yachters tend to be more concerned with creature comforts like at home. We're probably more akin to motor homers than the sail boat crowd from where I come. We have things like electric heat, air conditioning, microwave ovens, electric stove tops, large refrigerators and (gasp) big TVs. "We" not including Bernie and I.
Well yes, we purchased a motor yacht but we are out to avoid becoming full fledged motor yachters. We prefer a propane cook top over electric and solar power over a generator. We are accustomed to engine noise while underway since most of our cruising time in transit on Vela Via was during light air times while we were on a schedule. But once we arrive we want piece and quiet and fresh air. No generator running unless it is absolutely necessary.
My original plan was to ignore the generator putting off any work on it until I had nothing better to do. That was until the generator had to be moved out of the way for transom work. Since the generator was coming out of the boat I decided to bring it home where it would be easier to work on and I am free to work on weekends. Thus began the generators journey on Feb 13, 2018.
It was filthy work removing the rust bucket of a generator from the boat. As Steve (primo mechanic at the yard) was helping me hoist it out of the boat and onto the trailer I commented, partially out of frustration that I wasn't sure this thing would be returning to the boat. Steve encouraged me saying why not, those things cost $8,000 and if you need help troubleshooting anything just ask Cummins-Onan folks who are glad to help. I adjusted my thinking. I will also note that about this time we were still struggling with the our decision about the cook top having been told we'd need to enclose the tank in a locker. I blogged about that in a previous post. So for all I knew we might need this generator for cooking.
First order of business was to remove the rusted parts and begin the cleanup. There were two parts of particular concern, the drip pan and the part that supports the control box over the alternator. The support part was wasted away halfway across the top and along one side on the bottom. I wasn't sure what to do about it. I considered cutting out the corroded sections and scabbing on new pieces from home depot purchased sheet metal. I considered reconstructing the part out of plywood. I put the thinking on the back burner and focused on getting the drip pan off. This would require some way of lifting and supporting the generator which is normally supported by the drip pan. How might that be done?
I had rented an engine hoist aka cherry picker to get the generator out of the trailer, that was one option at a cost of $35 for 4 hours and required a couple of hours of pickup and drop off time. I considered using my 2 ton come along connected to the garage rafters. I decided to build a gantry. Mostly because of the cool name.
I spent a couple of hours chisel scrapping the pan. The corrosion is layered and brittle so it kind of flakes off. as seen in the video clip above. With the layers of corrosion removed and almost down to bare metal I treated it with a product called Corroseal. Corroseal is some kind of acid that converts the rust essentially into primer. Once treated it was ready for paint.
As I considered fixing the other parts I recalled high school metal shop where we had two wonderful machines. A metal brake does the folding of a sheet and a sheer does the cutting. Those machines are huge and I can neither build one or rent one so this left me seeking a metal fabricator shop. I found Accurweld right here in Washougal. I took my rusted parts down to ask them what they could do. They gave me an estimate of 3-4 hours which seemed reasonable to me. Even if I had those tools it always takes me twice as long as the professionals. I left the parts and returned home to resume other work.
I treated most of the other parts that would be easier reattach with the generator still out of the boat. I left the two side panels for later as my garage workspace was limited due to so much boat stuff temporarily taking up space.
There were also some deferred maintenance items due on the generator engine. I changed the oil. Cleaned and repainted the heat exchanger. Changed the fuel filter and checked the valve adjustment.
It took a couple of weeks for Accurweld to do their work. They did a great job from the specifications I provided (none). Rather than scab on new portions of sheet metal in place of the wasted sections they created complete new parts from stainless steel. That was the good news. The not so good news is that I forgot the specifications. What I should have done was give them every part along with the picture above so they would see how they were to fit together. The picture would've provided details such as how both bottom edges of that support structure should've been flanged where they bolt to the base. They would have been able to test fit the parts and measure to make sure it all fit together. But alas I neglected that important part. This meant several more hours on my part fabricating brackets to hook everything together as well as I could. Although not as neat and tidy as the original enclosure it will do.
The paint I used was a mixture of white and beige Rustoleum paint blended to approximate the off white color.
To be continued...
Unlike sailboats most motor yachts have a generator of some sort. Motor yachters tend to be more concerned with creature comforts like at home. We're probably more akin to motor homers than the sail boat crowd from where I come. We have things like electric heat, air conditioning, microwave ovens, electric stove tops, large refrigerators and (gasp) big TVs. "We" not including Bernie and I.
Well yes, we purchased a motor yacht but we are out to avoid becoming full fledged motor yachters. We prefer a propane cook top over electric and solar power over a generator. We are accustomed to engine noise while underway since most of our cruising time in transit on Vela Via was during light air times while we were on a schedule. But once we arrive we want piece and quiet and fresh air. No generator running unless it is absolutely necessary.
My original plan was to ignore the generator putting off any work on it until I had nothing better to do. That was until the generator had to be moved out of the way for transom work. Since the generator was coming out of the boat I decided to bring it home where it would be easier to work on and I am free to work on weekends. Thus began the generators journey on Feb 13, 2018.
It was filthy work removing the rust bucket of a generator from the boat. As Steve (primo mechanic at the yard) was helping me hoist it out of the boat and onto the trailer I commented, partially out of frustration that I wasn't sure this thing would be returning to the boat. Steve encouraged me saying why not, those things cost $8,000 and if you need help troubleshooting anything just ask Cummins-Onan folks who are glad to help. I adjusted my thinking. I will also note that about this time we were still struggling with the our decision about the cook top having been told we'd need to enclose the tank in a locker. I blogged about that in a previous post. So for all I knew we might need this generator for cooking.
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| Fresh out of the boat, note slumping control box |
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| Loaded on the trailer for the 90 minute ride home |
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| Sound shield schematic |
First order of business was to remove the rusted parts and begin the cleanup. There were two parts of particular concern, the drip pan and the part that supports the control box over the alternator. The support part was wasted away halfway across the top and along one side on the bottom. I wasn't sure what to do about it. I considered cutting out the corroded sections and scabbing on new pieces from home depot purchased sheet metal. I considered reconstructing the part out of plywood. I put the thinking on the back burner and focused on getting the drip pan off. This would require some way of lifting and supporting the generator which is normally supported by the drip pan. How might that be done?
I had rented an engine hoist aka cherry picker to get the generator out of the trailer, that was one option at a cost of $35 for 4 hours and required a couple of hours of pickup and drop off time. I considered using my 2 ton come along connected to the garage rafters. I decided to build a gantry. Mostly because of the cool name.
 |
| Home made come along gantry |
 |
| Gantry in action, drip pan removed |
I spent a couple of hours chisel scrapping the pan. The corrosion is layered and brittle so it kind of flakes off. as seen in the video clip above. With the layers of corrosion removed and almost down to bare metal I treated it with a product called Corroseal. Corroseal is some kind of acid that converts the rust essentially into primer. Once treated it was ready for paint.
 |
| Drip pan with most of the corrosion removed and the tools used |
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| Drip pan and other parts treated awaiting paint |
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| The alternator housing top ready for Corroseal |
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| Alternator housing reinforced with JB weld |
As I considered fixing the other parts I recalled high school metal shop where we had two wonderful machines. A metal brake does the folding of a sheet and a sheer does the cutting. Those machines are huge and I can neither build one or rent one so this left me seeking a metal fabricator shop. I found Accurweld right here in Washougal. I took my rusted parts down to ask them what they could do. They gave me an estimate of 3-4 hours which seemed reasonable to me. Even if I had those tools it always takes me twice as long as the professionals. I left the parts and returned home to resume other work.
I treated most of the other parts that would be easier reattach with the generator still out of the boat. I left the two side panels for later as my garage workspace was limited due to so much boat stuff temporarily taking up space.
There were also some deferred maintenance items due on the generator engine. I changed the oil. Cleaned and repainted the heat exchanger. Changed the fuel filter and checked the valve adjustment.
It took a couple of weeks for Accurweld to do their work. They did a great job from the specifications I provided (none). Rather than scab on new portions of sheet metal in place of the wasted sections they created complete new parts from stainless steel. That was the good news. The not so good news is that I forgot the specifications. What I should have done was give them every part along with the picture above so they would see how they were to fit together. The picture would've provided details such as how both bottom edges of that support structure should've been flanged where they bolt to the base. They would have been able to test fit the parts and measure to make sure it all fit together. But alas I neglected that important part. This meant several more hours on my part fabricating brackets to hook everything together as well as I could. Although not as neat and tidy as the original enclosure it will do.
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Drip pan and support platform repainted and installed. Heat exchanger serviced and painted. Test fit of control support.
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| The newly fabricated parts |
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| Generator assembled forward view |
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| Starboard side view. Note the side panels and access ports yet to be treated and painted |
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| Port side view |
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Aft end view
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