COR 15 rust

[Gtinnel]

I recently bought a used COR 15 pump from a forum member and when I started cleaning the pump I noticed what appears to be rust on the end of the impeller shaft. It’s right where the snap ring goes onto the shaft. I assume the shaft is ceramic and the snap ring is probably made out of some metal that won’t rust, so why would there be a tiny bit of rust there? Also, is there any reason not to take the snap ring off so that I can clean it up better?
I’m trying to decide if I need to buy a new impeller, snap ring, or just take it fully apart and clean it really well

 

[Dburr1014]

Even stainless steel will rust.

Probably will need a new one.

IMO, take it off carefully, clean it and personality, I would coat it with a reef safe grease before putting it back on. Just a little extra protection.

 

[Gtinnel]

I have always believed that stainless won’t rust.

So obviously the rust has to be coming from the snap ring then.

 

[Steve2020]

I have always believed that stainless won’t rust.

So obviously the rust has to be coming from the snap ring then.

There are many grades of stainless steel. Even some of the best grades ( 316 ) that has Molybdenum added will show some rust over time in a saltwater environment. I find it strange that a company like Neptune would use a stainless circlips and not titanium. I have 2 Ecotech Vectra's that have been running for over 2.5yrs with no rust at all but they are using titanium circlips. Call Neptune and ask for the size of the circlips and if it was me I would purchase some titanium ones. If you decide to stay with stainless circlips make sure you do not use carbon steel snap ring plier tips when removing the circlip. Only use stainless tips so not to contaminate the stainless circlip.

 

[Gtinnel]

There are many grades of stainless steel. Even some of the best grades ( 316 ) that has Molybdenum added will show some rust over time in a saltwater environment. I find it strange that a company like Neptune would use a stainless circlips and not titanium. I have 2 Ecotech Vectra's that have been running for over 2.5yrs with no rust at all but they are using titanium circlips. Call Neptune and ask for the size of the circlips and if it was me I would purchase some titanium ones. If you decide to stay with stainless circlips make sure you do not use carbon steel snap ring plier tips when removing the circlip. Only use stainless tips so not to contaminate the stainless circlip.

My experience with reaching out to Neptune Systems about questions has not been successful for me in the past. I will probably just use some vernier calipers to measure the shaft diameter and I’ll have to figure out something for measuring the groove diameter.
I will definitely try to find titanium rings but if not I’ll at least replace it with a stainless one, since I know it’ll be easy to find.

I am intrigued by the part about using snap ring pliers with stainless tips instead of carbon steel. Since carbon steel is harder than stainless (or at least from a quick google search it seems to be) then would there be an issue with the carbon steel contaminating the stainless, wouldn’t it be the other way that the softer metal would contaminate the harder metal? If that is an issue why wouldn’t the same be true for titanium? Also I would think the amount of contamination between the two metals would have to be negligible or am I wrong about that?

 

[Dburr1014]

My experience with reaching out to Neptune Systems about questions has not been successful for me in the past. I will probably just use some vernier calipers to measure the shaft diameter and I’ll have to figure out something for measuring the groove diameter.
I will definitely try to find titanium rings but if not I’ll at least replace it with a stainless one, since I know it’ll be easy to find.

I am intrigued by the part about using snap ring pliers with stainless tips instead of carbon steel. Since carbon steel is harder than stainless (or at least from a quick google search it seems to be) then would there be an issue with the carbon steel contaminating the stainless, wouldn’t it be the other way that the softer metal would contaminate the harder metal? If that is an issue why wouldn’t the same be true for titanium? Also I would think the amount of contamination between the two metals would have to be negligible or am I wrong about that?

I think you are right.

Should get in that Groove easy enough with verniers. The tips are usually thin for times like these. Or at least machine verniers, not ones for brakes and such.

 

[exnisstech]

I am intrigued by the part about using snap ring pliers with stainless tips instead of carbon steel. Since carbon steel is harder than stainless (or at least from a quick google search it seems to be) then would there be an issue with the carbon steel contaminating the stainless, wouldn’t it be the other way that the softer metal would contaminate the harder metal? If that is an issue why wouldn’t the same be true for titanium? Also I would think the amount of contamination between the two metals would have to be negligible or am I wrong about that?

I think this is a case of over thinking things (not on your part but the comment about carbon snap ring pliers.) I use general mechanics tools and have even dropped them in the water with no I'll effects that I can tell. I think sometimes caution turns into paranoia in this hobby.
On a side note I have a mp40 that has rust at the base of the ceramic shaft. I'm not really sure of the cause unless some gfo powder got inside somehow and it's not even rust I still use the mp40 and last ICP didn't show anything strange.

 

[Gtinnel]

I think this is a case of over thinking things (not on your part but the comment about carbon snap ring pliers.) I use general mechanics tools and have even dropped them in the water with no I'll effects that I can tell. I think sometimes caution turns into paranoia in this hobby.
On a side note I have a mp40 that has rust at the base of the ceramic shaft. I'm not really sure of the cause unless some gfo powder got inside somehow and it's not even rust I still use the mp40 and last ICP didn't show anything strange.

Yesterday I broke a piece of a razor blade off in the tank and although I did find it, I about gave up and just left it. I also had a dosing container once that had a screw fall in it and rust so at some point I was dosing rust along with my trace elements. My tank is no stranger to a some rust.

I really should send in an icp since I haven’t in over a year.

 

[Gtinnel]

I think you are right.

Should get in that Groove easy enough with verniers. The tips are usually thin for times like these. Or at least machine verniers, not ones for brakes and such.

The calipers are a nice pair of mitutoyo vernier calipers and you may be right the tips may fit down into the groove.

 

[exnisstech]

I really should send in an icp since I haven’t in over a year.

I've only done icp once. I sent in a sample from 2 tanks mailed in seperately. The problem I have is I used ATI and they test rodi also. I sent samples of RODI with both tank water samples. The rodi was from the same container but the results were way different. Kind of destroyed my confidence in the test accuracy.
I suppose as a last resort chasing an unknown I might do one again with a different company but it will never become a routine thing for me

 

[Gtinnel]

I've only done icp once. I sent in a sample from 2 tanks mailed in seperately. The problem I have is I used ATI and they test rodi also. I sent samples of RODI with both tank water samples. The rodi was from the same container but the results were way different. Kind of destroyed my confidence in the test accuracy.
I suppose as a last resort chasing an unknown I might do one again with a different company but it will never become a routine thing for me

I have only submitted an icp once and it was the cheap fauna Marin icp. I actually bought another test but never did it, so I just need to get motivated to get the sample and mail it in.
I have no clue how accurate these tests are but figured it would help point out if there was any major problems, but since I’m not currently having any unknown corals problems then I doubt it’s too important.

 

[Steve2020]

I think this is a case of over thinking things (not on your part but the comment about carbon snap ring pliers.) I use general mechanics tools and have even dropped them in the water with no I'll effects that I can tell. I think sometimes caution turns into paranoia in this hobby.
On a side note I have a mp40 that has rust at the base of the ceramic shaft. I'm not really sure of the cause unless some gfo powder got inside somehow and it's not even rust I still use the mp40 and last ICP didn't show anything strange.

If you use a non plated carbon steel tool that has any small particles of rust on them which most do, and you put a microscopic scratch on stainless it will eventually rust especially in saltwater. I was just stating a fact because Gtinnel did not know that stainless can rust.

 

[exnisstech]

If you use a non plated carbon steel tool that has any small particles of rust on them which most do, and you put a microscopic scratch on stainless it will eventually rust especially in saltwater. I was just stating a fact because Gtinnel did not know that stainless can rust.

My apologies

 

[Gtinnel]

If you use a non plated carbon steel tool that has any small particles of rust on them which most do, and you put a microscopic scratch on stainless it will eventually rust especially in saltwater. I was just stating a fact because Gtinnel did not know that stainless can rust.

Ah so the issue isn’t with some of the metal from the tool contaminating the snap ring, but allowing a place for the rust to start developing?

 

[Dburr1014]

Interesting read

https://www.reliance-foundry.com/blog/does-stainless-steel-rust#:~:text=Stainless%20steel%20is%20naturally%20corrosion,of%20time%20can%20cause%20corrosion.

Some things I did not know.

OP, you may want to replace that ring also because those tiny rings bend easily and it might lose some of its retention.

 

[Gtinnel]

Interesting read

https://www.reliance-foundry.com/blog/does-stainless-steel-rust#:~:text=Stainless%20steel%20is%20naturally%20corrosion,of%20time%20can%20cause%20corrosion.

Some things I did not know.

OP, you may want to replace that ring also because those tiny rings bend easily and it might lose some of its retention.

When I take the ring off I will definitely be replacing it with at least another stainless one. I’m hoping to be able to easily find a titanium one.

 

[opwan]

I recently bought a used COR 15 pump from a forum member and when I started cleaning the pump I noticed what appears to be rust on the end of the impeller shaft. It’s right where the snap ring goes onto the shaft. I assume the shaft is ceramic and the snap ring is probably made out of some metal that won’t rust, so why would there be a tiny bit of rust there? Also, is there any reason not to take the snap ring off so that I can clean it up better?
I’m trying to decide if I need to buy a new impeller, snap ring, or just take it fully apart and clean it really well

Where can we buy the impeller?

 

[Gtinnel]

Where can we buy the impeller?

Sorry but I have no idea. I looked on Neptune systems website and they don’t have any parts for any pumps in stock it looks like.