6105 shaft ends rusted

ReefAnon

New member
Having used Tunze pumps for over a decade I was horrified to find that the shafts on my new 6105s had both rusted at the back ends. On closer inspection I found what I think is the cause - it looks like the shiny plating has disintegrated and started to come away exposing the metal underneath. I thought they were supposed to be titanium? The is no sugar sand in the tank that might have got stuck in them or anything else that could have caused damage.

I am also still having problems with the brackets not keeping them in the same position - as advised I did squeeze them together but stopped when the plastic showed signs of stress.

My old Tunze pumps never did this over years of service so I am very disappointed at the problems with the new ones :( I can post some pics if it helps...
 
The older 6105 shafts are made of a Titanium alloyed stainless steel, they are not plated. The nusuiance rusting you see is due to the crevice formed at the bushing. It doesnt seem to effect operation of the pump, but makes it a pain to get the magnet off for cleaning. You can simply scrub the rust spot with steel wool and it will work fine.

Tunze just recently changed shaft material to a commercially pure Titatnium grade which eliminiates this rusting.


HTH
 
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Thanks, I could do that of course but I don't want rust in my tank and wasn't expecting any from Tunze. The pumps are only a few months old.
 
Ironically, people add rust to there tank all the time, (granular ferric oxide phosphate remover), it does no harm and this is a superficial surface corrosion as Andy explained. Tunze UK should be able to get you the new Titanium shafts if you just contact them.
 
I'm aware of GFOs [iron oxide hydroxide] and I'm not sure it's chemically the same thing as rust - see RFH in http://reefkeeping.com/issues/2004-11/rhf/index.php "There is no ferrous iron in GFO" though I may have misinterpreted the statement. As it happens I don't use GFO and don't wish to add iron to my tank.

However, that is beside the point. My concern is the build quality of the pumps as I have 4 of them which cost a considerable amount. If I contact Tunze UK will I be charged for the replacement shafts?

What about the holding clips? I did bend them as you (Roger) suggested but the fit is still loose. It is better as I'm now only having to re-position them once a week or so rather than every day but it's hardly ideal. I'm reluctant to apply any further pressure as I saw stress on the plastic and don't want to break them. They almost seem to be slightly the wrong shape as they grip at the tips but not in the middle.

Thanks,

Daniel
 
I would contact Tunze UK, there is no set policy on the shafts or clamps as mostly these are cosmetic issues but they generally will replace them at no charge if they were purchased within the last 6 months and with only a small charge after that to cover shipping. The clamp grip you describe is normal it reduces the contact area which transmits vibration. Another good squeeze will likely be all it takes to resolve that issue.

GFO is indeed rust, ferrous oxide is smiths black or the black form of iron oxide. It is completely harmless to a reef aquarium.
 
It may be better in that case to just contact Tunze Germany directly at info at tunze dot com, those emails go direct to the factory. Info dot english at tunze dot com comes to me.
 
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