Stan's ate my rims.... WARNING

[gotbikes]

After two years my Campy Zonda two-way-fit front started needing refilling every ride so I pulled the Hutchinson Intensive tire off and found lots off corrosion pits on the black anodized rim. I cleaned the rim and fitted a new tire, since it was going to take a while to clean the Stan's guck out, and without putting more sealant in, the newly filled tire pressure dropped to zero in a matter of minutes. When I tested it in a water tank the air was escaping through the ventilation hole in the rim wall! Clearly, in one or more of those pits, the corrosion had eaten right through the rim!

I am VERY unhappy. I cannot reliably use tubeless again on this rim! Now there's the rear to deal with and the pair of Zondas on my son's bike and the pair of DuraAce conversions on my wife's bike. I converted these three bikes purely for safety reasons - our rides are up and down the Niagara Escarpment and my son's riding is in the Hollywood hills - both areas have some pretty hairy descents.

There seems to be no clear consensus as to what's going on here - Stan swears his sealant doesn't corrode rims. What is it then - the air? My bike has never been ridden in the rain. Do we just replace these $3000.00 worth of wheels every two years to continue the tubeless program? Cleaning out the Stan's periodically and refreshing would not have helped if the stuff is this corrosive.

[perwjensen]

The cause is ammonia. Cafelatex is formulated with out use of ammonia.

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[perwjensen]

Quote from the Stan's website... http://www.notubes.com/FAQ.aspx

"I heard there is ammonia in your sealant and it is bad for my tire and or rim?
Any trace amount of ammonia in Stan’s sealant will evaporate soon after it is injected into the tire. We have found no damaging effects from our sealant even after years of use. Any oxidation in your rim will just as likely be caused by riding in wet conditions or the humidity in the air. Although tape may not be necessary to seal your rim, you may add one layer to protect un-anodized or scratched areas of your rim from oxidation due to moisture in the sealant."

I suspect that, unless you can prove there were no scratches or nicks in the rims before you applied the sealant, you will be out of luck trying to claim any damages.

It's more than thirty years ago I studied material science, so forgive if my recollection is not correct.

Aluminum is highly corrosion resistant, because the oxidization creates a very hard and protective layer. However, galvanic corrosion ( think salt water) can eat away at aluminum. Also, stress corrosion with the presence of, yes you guessed it ammonia, will eat aluminum.

Where is the evaporating ammonium going to disappear to? Thin air?

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[perwjensen]

Stan's shows their lack of knowledge in that statement. Aluminum corrosion is well understood, and if moisture stripped the protective oxide layer, millions of aluminum extension ladders laying in residential backyards would have long since turned to dust.

Yeppers

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[speedyvelo1]

I have a pair of Campag Zondas new Dec 2011 in April 2012 I decided to run them as tubeless with Hutchinson Fusion3 and Stan's sealant.
I was really pissed off to find that Stan's had eaten through my front rim in one spot and had attacked the the rim in about 10 other spots.
The rear is not as bad but show signs of attack, I guess it was getting cleaned out more often.

Greg,

Yes it happens. I have a pair of Shamals and they have, even not as bad as yours, some corrosion. My wheels have many thousands miles so I've just ignore it and keep using it because I have not flats and everything is perfect with that exception. I have a new pair of Shamals and when I start to use them, the sealant will be Caffelatex that has synthetic ammonium and it does not cause corrosion. I am very aware of Caffelatex does not seal cuts as large a Stan's does but is you can also also carry zot! from the same company and that works very well. I like Stan but corrosion of aluminum rim is a problem. It is true that not everybody has the same problem and many thinks is related to how the aluminum rim is treated painted etc. I bough caffelatex and zot! they had a good price in Wiggle but I have not use them yet.

[UpFromOne]

I heard all that about Stan's and would never touch the stuff. I've used Orange Seal since the day it came out. Never a problem of any kind.

[euka]

It's more than thirty years ago I studied material science, so forgive if my recollection is not correct.

Aluminum is highly corrosion resistant, because the oxidization creates a very hard and protective layer. However, galvanic corrosion ( think salt water) can eat away at aluminum. Also, stress corrosion with the presence of, yes you guessed it ammonia, will eat aluminum.

I've broken couple of aluminium handlebars due oxidisation. The rootcause was sweating while riding indoors.

[ooo]

Ammonia-free sealant :

CaffeLatex
Flat Attack
Orange Seal
Bontrager TLR
Conti RevoSealant
Hutchinson ProtectAir

Ammonia-based sealant :

Stan's No Tubes
Vittoria Pit Stop
Geax PitStop TNT

Unknown :

Specialized AirLock

[perwjensen]

It's more than thirty years ago I studied material science, so forgive if my recollection is not correct.

Aluminum is highly corrosion resistant, because the oxidization creates a very hard and protective layer. However, galvanic corrosion ( think salt water) can eat away at aluminum. Also, stress corrosion with the presence of, yes you guessed it ammonia, will eat aluminum.

I've broken couple of aluminium handlebars due oxidisation. The rootcause was sweating while riding indoors.

Yes, I can see that water salt would be a driver too. But, should be slow going. I have seen a number of boats built out of aluminum lasting forever in sea water.