Old "new" impeller?

Is a 20 + year old, but still new in the package (never used) rubber impeller still good? Im helping my brother-in-law get his 1985 Hunter 40 back in shape. The boat has not seen much use in the last 20 years and if you can believe it, has the original impeller. He has this new in the box spare impeller he purchased some 20 (or more) years ago but Im not sure that installing that old of a rubber impeller in the engine is a good idea. It was stored in a dark, temperature stable environment, but how will rubber that old perform under the flex stresses imposed on an impeller? Any thoughts? *
Thanks.
SteveH


-- Edited by SteveH on Tuesday 1st of February 2011 09:37:06 PM

I'd buy a new impeller and toss the old one!

Chances are the impeller in use is the same as the spare. Apparently both are still good after 20 years!

For that little sailboat engine they have got to be cheap. I would get a new one.

The properties of rubber (if it's a rubber impeller) can change over time and can change due to the temperatures it's exposed to. It can become harder, more brittle, less flexible, etc. even if it seems to be okay. As Doc says, given the low cost of impellers I think it makes far more sense to simply buy a new one than hope that the 20-year old one has retained all it's properties.

I would replace it also. The old new one and the old used one become get home spares.

Jack, is that the crew of the Atlantic Salvor in your avatar, or were they just strolling down the dock?
Steve W.

Nobody likes the 20 year old spare.

When you buy a "new one" don't get one at the boatyard it may have been laying on the shelf for 20 years.

JohnP

When replacing impellers on Moonstruck, I use the one from the spare parts kit I carry.* Then replace the spare with a new one.* Rotate the stock.* Rubber deteriorates with age. Same with fuel filters, oil filters, and belts.

-- Edited by Moonstruck on Wednesday 2nd of February 2011 04:07:25 PM

-- Edited by Moonstruck on Wednesday 2nd of February 2011 05:42:59 PM

I ordered a Speed Seal and it came with a handy little gadget to remove the old impeller.

*Pulled the old one without any damage to it.

*I'll keep it for a spare.

SD

How hard is it to change? Then ask yourself,"if it fails, how many hours of my life will I loose changing it again compared to the price of buying a new one now".

Impellers are like fan belts, oil, and filters. Always replace them before they go bad with quality components. The potential cost from their failure can be well over 100 times the cost of the component.

Ted

O C Diver wrote:
How hard is it to change? Then ask yourself,"if it fails, how many hours of my life will I loose changing it again compared to the price of buying a new one now".

Impellers are like fan belts, oil, and filters. Always replace them before they go bad with quality components. The potential cost from their failure can be well over 100 times the cost of the component.

Ted

Click to expand...

I would add this question. Would you rather change it in the comfort of your own slip, or rolling in the trough in stormy seas?

*

Thanks for all the inputs. I think we'll be erroring on the side of safety and installing a new "fresh" impeller and keep the old "new" one as a spare. This boat, a 1985 Hunter 40 was outfitted presumably at the factory, with the raw water filter unit located where it's blocking any and all access to the impeller, making it utterly impossible to change the impeller without completely removing the raw water filter and it's hoses! A potentially dangerous situation while underway. So besides changing the impeller we will be relocating the raw water filter as well.

SteveH

SteveH wrote:

Thanks for all the inputs. I think we'll be erroring on the side of safety and installing a new "fresh" impeller and keep the old "new" one as a spare. This boat, a 1985 Hunter 40 was outfitted presumably at the factory, with the raw water filter unit located where it's blocking any and all access to the impeller, making it utterly impossible to change the impeller without completely removing the raw water filter and it's hoses! A potentially dangerous situation while underway. So besides changing the impeller we will be relocating the raw water filter as well.

SteveH

Click to expand...

Steve, throw the old "new" one away and buy 2 new ones. You have determined that the spare you have now would be a poor choice to install. It's not going to improve as it continues to age. This is like replacing a cracked fan belt and saving the old one as a spare. If it's not good enough to use, it's not good enough to be a spare.

Ted

*

"Steve, throw the old "new" one away and buy 2 new ones. You have determined that the spare you have now would be a poor choice to install. It's not going to improve as it continues to age. This is like replacing a cracked fan belt and saving the old one as a spare. If it's not good enough to use, it's not good enough to be a spare."

Absolutely. Not even a question. You don't want tp mess around with the raw water system...it is the lifeblood of a marine engine.

Steve they worked at Hooters (on the waterfront where the tug was ) in Norfolk

Yea, you guys are right. What was I thinking? It's out with the old and in with the new. Thanks guys!

SteveH

Hi Charles, and thanks for the tips. I've changed out a few impellers before and actually used the zip type technique. I was kinda proud of myself thinking I came up with that idea, but it looks like I'm not the first to think of it...., oh well. A problem that I did encounter while trying to slide the new impeller down the spline was the bottom of the blades would poke into the inlet and outlet journals on the inside wall of the impeller housing preventing the impeller from sliding into position. I cut a sleeve of thin plastic from a note book cover the same width as the depth of the housing and long enough to cover the inside circumference so in effect, the plastic covered the journals allowing the impeller to slide home. After that I just snipped the zip tie and pulled it and the plastic sleeve out with a needle nose and, Voila..., job done.*

SteveH

Old Stone wrote:

Dave - Do you like the Speed Seal? Always been tempted. Seems totally logical.

They say that tool comes with it as a free extra. I always thought it would be worth it just for that tool alone.

Click to expand...

Well I can't say for sure one way or another yet.

One thing for sure I won't have to pull the entire raw water pump off just to change the impeller.

The concept is a great idea if you go to there web site and look at there product.

They don't explain the bearing idea but the concept is . The cover is similar to the cover you now have only thicker.**the center is machined out and a small plastic disc is inserted behind a thin brass disc. the impeller spins on the disc which spins on the plastic inserted disc not just on the cover of the pump.

*Instead of those small slot brass* machine screws. (That if you don't have the exact size screwdriver the head always* strip.)**There are 4 knurled grippable heads that all it takes is to finger tighten to compress the O ring. (No more scraping off the paper gasket.) The cover is slotted for two of the mounting screws. So all you have to do is loosen two and remove the other two.

The cover slides right off.

Oh yea they provide a lubricant to make everything easy to assemble.

I installed it this winter but I havent started her up yet. We will see this spring how well it holds up.*

SD


-- Edited by skipperdude on Thursday 17th of February 2011 11:18:39 AM

I have a speed seal cover and love it. If you buy one, go ahead and buy a spare knurled nut in case you lose one, and a spare O-ring. I keep a little bag in the ER with a new impeller, zip tie, silicone plumbers grease, impeller puller and pair of pliers. I bet I can change the thing out in 5-10 minutes, with most of that time crawling over there and getting in place.

Of course, if you change them often enough at the dock, you don't have to do it in a pitching sea next to a hot engine!

Keith--- What kind of impeller puller do you use? I have contemplated getting one but have heard so many conflicting testimonials--- they're great, they're worthless--- that I've not yet bothered to check them out.

Jabsco, I think it's the larger one. They have two sizes. No matter how or what I use to lube up the spline and shaft, I still normally have to use the puller to get the old one out easily. You really just have to get it started...once it's out maybe 1/4 or 1/3 of the way, you can just grab the puller and pull the whole thing out.

Keith wrote:

Jabsco, I think it's the larger one.

Click to expand...

Thanks much.

*