Re: [Amel Yacht Owners] Re: Globe Run Dry Impellers
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Bronze is very easy to machine and you don't have to use a mill or anything fancy for a job like cleaning up rough areas inside your pump housing. One option is to use a drum sander just under the ID of the casting. I would start with about 80g and once the imperfections were removed work down to finer grits, finishing with w/d down to about 600g. Move the drum in and out so that you don't cut grooves. You could even polish the last of the scratches out using fiberglass or metal polish. Just wash the housing out really well to remove the abrasive. I wouldn't worry about taking a little metal out in this process if needed. Best of luck, James
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From: "'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]" <amelyachtowners@...>
Date: 06-09-2016 10:44 AM (GMT-04:00)
Subject: RE: [Amel Yacht Owners] Re: Globe Run Dry Impellers
For my two cents...
I think this modification has numerous issues and would caution the attempt to re-engineer what Cummins Onan has done.
I believe that you need to address these things if you proceed with this:
Water flow and water flow pressure - While the March magnetic drive may have the reguired flow specifications, it may not have the force of flow. AND, most importantly what is the required flow. It seems to me that the flow could possibly overwhelm the exhaust 's ability to clear the wet muffler...if that happens, good-bye Onan.
Where to connect the pump to 230VAC? I assume that you would want to connect it to the same place as the exhaust fan. Is there sufficient current available? Is that going to be properly fused?
Will the flow sensor work properly? What are those specs?
What are your plans to seal the port for the existing pump? If you leave the pump in place, will it be OK free-running without an impeller and the water to cool the casing?
My bottom line is that none of us has all of the information to make this decision, and I do not envision Onan giving any of us what we need to do this. I will not be doing this modification because I do not want to bet the cost of a new generator for something that nobody can be sure of.
On another note regarding the saltwater pump that Onan selected for this generator, I belive the original casting is poorly done and the inside of the pump needs to be machined slightly. The last time I changed the impeller (The dreaded Globe Run-Dry) I noticed a casting imperfection. When I was cleaning the inside of the pump with Wet-dry sandpaper, there were obviously two spots that were bad. I want to try to have this pump machined/polished. Has anyone done this?
On Jun 9, 2016 8:24 AM, "'Mark Erdos' mcerdos@... [amelyachtowners]" <amelyachtowners@...> wrote: