Raw water impellers

[seafox]

I empty and clean my 2 raw water impellers strainers, engine & gen, every 3 to 4 weeks. It was suggested that I add a little dish soap in the strainers to lubricate the impellers. It sounds reasonable but putting dish soap through the impellers could break up the grease that was used when installing new impellers?????????
Someone else suggested adding some cooking oil to the strainers after cleaning them to keep the rubber impellers lubricated.
This actually sounds better and makes some sense.
Any thoughts?

 

[JamesG161]

I would think it would only be "momentary" effects. The grease would be better than dissolvable soap, but again only for a while.
Normally the resiliency of the rubber is the wearing reducer.
Jim...

 

[SG]

Why are you cleaning your impellers every two weeks? or you just cleaning your strainers?
I understand why your generator strainer MIGHT get some grass in it -- but your engine's strainer shouldn't normally? What's up?

Unless your installation is different, I would't mess with the impellers. I'd just clean the stainer, allow it to "fill" by opening the seacock. Then just keep going.


P.S. -- I use Superlube (not very much) on the impellers. It's a Teflon based lubricant. You don't want a petroleum based product because of the rubber.

 

[Justin_NSA]

I would think it would only be "momentary" effects. The grease would be better than dissolvable soap, but again only for a while.
Normally the resiliency of the rubber is the wearing reducer.
Jim...

You said it better than me. Nothing you put in the line will linger long.

 

[seafox]

Thank you for your thoughts. Appreciate it. I only cempty the strainers and yes both, when I have to.. I have been spending the last couple of months in Miami and the Keys and there seems to be much grass and debris floating around.....Probably thanks to Irma!
I empty and clean ONLY the strainers. I change the impellers 12 to 18 months and use the proper grease. I have a 75 HP YANMAR and those of us that have that engine, changing the impeller is not the most enjoyable task. The genie is easy. But I digress......
The question is: does anyone add a small amount of oil when emptying the strainers to lub the rubber impeller and has it proven useful?

 

[Justin_NSA]

How would you measure that usefulness? Ease of installation? Longevity? It would take some time to get comparison data on wear.

 

[Gunni]

What does your impeller look like when you remove it at 12 months? 18 months? That is the measure of any problem. Heat is the enemy of an impeller - that means restricted water flow and friction within the raw water pump volute. Make sure your raw water flow remains strong (strainer, heat exchanger, mixing elbow) and consider using a speed seal Life which provides a rotating bearing for the impeller against the side plate. When I remove my impeller from the Speedseal Life from my auxiliary at one year there was no wear or crazing on the impeller. When I remove the impeller from my genset at one year (with simple bronze cover plate) the impeller shows significant wear and some cracking of the impeller vanes.

 

[Justin_NSA]

When I remove my impeller from the Speedseal Life from my auxiliary at one year there was no wear or crazing on the impeller. .

I upgraded from the PO's Speedseal to the Speedseal Life. I haven't removed the impeller to see how it looks. I read somewhere that sailors remove impellers over the winter to let them regain their shape. The impeller I mean.

 

[Benny17441]

I follow manufacturer recommendations and there is no mention about the need for lubricating the impeller. Oil degrades rubber and soap tends to dry rubber out so I don't see any benefits from either. The solution to prevent a sticking impeller is to run the engine periodically. Most strainers come with a transparent inspection cap so we can know when they need cleaning. Every time we mess with any component there is a risk factor that something can get damaged, hence the old adage, "if it ain't broken don't fix it".

 

[Gunni]

I read somewhere that sailors remove impellers over the winter to let them regain their shape. The impeller I mean.

The chemical compatibility testing done by Thinwater and the Practical-Sailor team indicated that raw water impellers (and lots of other plumbing parts) are eaten alive by the ethyl alcohol and propylene glycol in common winterizing antifreezes. Therefore it makes good sense to remove the impeller after completing winterization, rinse and stow. I'm basically too lazy to do so.

 

[Justin_NSA]

The chemical compatibility testing done by Thinwater and the Practical-Sailor team indicated that raw water impellers (and lots of other plumbing parts) are eaten alive by the ethyl alcohol and propylene glycol in common winterizing antifreezes. Therefore it makes good sense to remove the impeller after completing winterization, rinse and stow. I'm basically too lazy to do so.

Good intel. Thanks Gunni. I should remove mine next time I'm at the yard.

 

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[chuckwayne]

I remove my impeller after winterizing, rinse with fresh water, inspect, and store coated with glycerin - protects and lubes the rubber.
I agree anything you put in will wash/rub off really fast and won't do much

 

[seadaddler]

I have found also to remove the front of heat exchanger on my 3YM
every so often and do find some sea grass and even once found a piece of impeller vane.
Not really hard to do and even reused the O ring.
Nick