Removing dried sealant on rims -- help

[Keith A]

A while back I purchased a set of Dura-Ace WH-7850-C24-TLs from a member of our forum. Unfortunately, the previous owner had used some sealant in there which had corroded some of the rim surface. I should have sent them back since this damage was not mentioned during the purchase of these wheels, but I neglected to do so and stuck them in the corner in frustration.

I finally decided to use these with tubes, as there is no way they could seal with a tubeless setup. I have been working on removing the dried sealant and this is a pain the backside!!! I've tried scraping, moistening this, mineral spirits, Dawn soap, and scrubbing with a stiff nylon bush. I have been able to remove much of this with plenty of elbow grease, but there is a still a fair amount that remains.

I've done some research on the Internet and nothing has popped out that seems like it would work. This stuff is really stuck to the rim, and would appreciate any suggestions on how to remove the remaining bits.

Here's a sample of what it looks like. It almost looks like rust on there, but as we all know, aluminum doesn't rust.

[Tony]

Lacquer Thinner may be helpful in removal? Pictures looks like some oxidation on the rim?

[Fatty]

Looks kind of ugly. A little toothbrush size brass brush might get in there.

[AngryScientist]

have you got a dremel Keith?

if not you should buy one, they are great for a whole bunch of stuff.

if you do, get a felt polishing wheel, dip it in mineral spirits and go to town. should make short work of that goop.

http://147sko1406zi1hs2j74emh3jf5g.wpengine.netdna-cdn.com/wp-content/uploads/2009/07/attach-felt-2.jpg

[Bentley]

I've used Isopropyl (rubbing alcohol) and a scothbrite successfully before. My guess is they used Stans sealant which is corrosive. I use Orange Seal, no issues

Best

Ray

[Dead Man]

Life hack: Methyl Ethyl Ketone removes everything.

Can be hard to find in some areas, as it's a common prep chemical for illicit clandestine "labs."

[Keith A]

Thanks for the replies so far. Yes, they ain't pretty (although the other rim is in better shape) and there is certainly damage to the rim surface from the sealant. Some of the damage is superficial (top layer), and looks like oxidation, but there are other areas were part of the rim material has been eaten away by the sealant.

AngryScientist -- I do have a Dremel and will need to check and see which attachments I have. I've been thinking this might be my next step.

Bentley -- I did try rubbing alcohol, but not with a Scotch-Brite pad.

Dead Man -- Totally unfamiliar with "Methyl Ethyl Ketone", but it seems like some potent stuff. Any precautions in working with this?

[Black Dog]

Acetone. AKA nail polish remover.

As with all solvents. Use outside and try not to inhale, wear eye protection and gloves.

[Dead Man]

Dead Man -- Totally unfamiliar with "Methyl Ethyl Ketone", but it seems like some potent stuff. Any precautions in working with this?

Treat it like you would any other volatile organic compound (every chemical mentioned in this thread, basically), and you shouldn't poison yourself... but definitely be really careful not to let it touch carbon parts or anything else non-metallic, I'd say. It's the only consumer-grade solvent I'm aware of that'll dissolve epoxy, for instance... nasty stuff. Excellent stuff.

[peanutgallery]

This is why I don't use Stans anymore

Check the nipples as they corrode before the rim, I've seen them basically turn to dust

[Idris Icabod]

Dead Man -- Totally unfamiliar with "Methyl Ethyl Ketone", but it seems like some potent stuff. Any precautions in working with this?

Acetone would do the same thing, it's almost the same with an extra methylene group at one side of the carbonyl group.

[rwsaunders]

I recall that Shimano posted warnings about using alkaline based sealants with those particular rims and there are snippets out there on the web (see below) regarding the potential damage. After you clean them, you might want to inspect them very carefully.

http://www.bikeforums.net/road-cycling/787958-dura-ace-7850-tubeless-wheels-corrosion-issues.html

[Keith A]

Thanks for the additional information!

rwsaunders -- I've read about others having the same issue and am aware of Shimano's statement that using a sealant will void their warranty. I've never used any sealant on my tubeless wheels -- and as I mentioned, I bought these from a forum member and they arrived in this condition.

As far as inspecting them for any potential problems, it seems like a little bit of material missing here and there would still be safe to ride?

[batman1425]

I'd be on the fence about safety. Anything that weakens the rim wall, which is dealing with a whole lot of force from the tube could be a very big problem. Will it fail? Who knows, but I'm very conservative about parts that have catastrophic failure modes for the rider during normal use (wheels, stems, steerer tubes, etc.)

The 7850 rims have a carbon layer laminated over the base of the rim - which I think is structural. I'd be very careful to keep any of the solvents mentioned away from that carbon if you go that route. Could do bad things to the resin and cause further structural decay. This would include trying to keep it from dripping into the spoke holes while you are cleaning though if memory serves, these have a solid rim bed, which will make things easier.

How far back are we talking? May want to talk to the seller again, especially if you discover any significant structural damage after removing the dried on stuff. Is there a "statue of limitations" on such things?

[Keith A]

batman1425 -- Thanks for your helpful reply, and you make some valid points about not taking a chance with a part that would cause a serious problem if it fails. As far as returning them, it's certainly been more than a year...and I should have acted on this when I first saw the issues :(

[Bentley]

Methyl Ethyl Ketone is a great solvent but it's also a bad carcinogen. I've worked in the aerospace industry and it was used to clean everything. Also causes liver cancer. It is also a bad thing to use near Titanium, it can cause Hydrogen embrittlement. It's typically found in Brake cleaner.

I would use a less agressive solvent, alcohol or Mineral Spirits and elbow grease. My 2 cents

Ray

[Dead Man]

It is also a bad thing to use near Titanium, it can cause Hydrogen embrittlement

eh?

Have a source? Not doubting you, but would like to read up on this. MEK has been used to clean Ti for as long as both have existed together.

[rwsaunders]

Thanks for the additional information!

rwsaunders -- I've read about others having the same issue and am aware of Shimano's statement that using a sealant will void their warranty. I've never used any sealant on my tubeless wheels -- and as I mentioned, I bought these from a forum member and they arrived in this condition.

As far as inspecting them for any potential problems, it seems like a little bit of material missing here and there would still be safe to ride?

Yep...I understood that you purchased the wheels secondhand and it is pretty clear that the previous owner used sealant. Regardless of the timing, I'd reach out to the seller and confirm exactly what product he/she used. That may give you a jump on the cleaning recommendations, as well as the cause of the corrosion.

As far as riding on the wheels, I was on a ride two years ago where somebody had a rim sidewall blow out due to brake wear and it wasn't pretty. We are talking an 8-10 cm spilt where the sidewall meets the rim. They were using tubes and the explosion sounded like a canon shot. I can imagine that if you have some level of deep corrosion that's taken place, that it might raise a concern.

Just be careful and perhaps ask somebody like Ergott or OP to chime in.

[Bentley]

Materials Engineer I worked with told me. I've accepted it as fact. It's a Halogenated hydrocarbon as I recall so it made sense.

I could be wrong, but I try to avoid anything but mild aromatic solvents near Ti.

Always open to hearing that I am mistaken

Ray

[batman1425]

batman1425 -- Thanks for your helpful reply, and you make some valid points about not taking a chance with a part that would cause a serious problem if it fails. As far as returning them, it's certainly been more than a year...and I should have acted on this when I first saw the issues :(

Thats a bummer Keith, sorry to hear of your experience. I hope you are able to find a resolution that you are comfortable with.

[Idris Icabod]

Materials Engineer I worked with told me. I've accepted it as fact. It's a Halogenated hydrocarbon as I recall so it made sense.

I could be wrong, but I try to avoid anything but mild aromatic solvents near Ti.

Always open to hearing that I am mistaken

Ray

I hate to be pedantic on the internet, but MEK isn't halogenated nor is there any proof that it is a carcinogen. I think you might be thinking about DCM?

[Dead Man]

I hate to be pedantic on the internet, but MEK isn't halogenated nor is there any proof that it is a carcinogen. I think you might be thinking about DCM?

I did a fairly intense albeit short scouring of teh googelz and found some kinda obscure NASA studies on halogenated compounds and titanium, but I couldn't find anything related to MEK and Ti. Except examples of using MEK to clean Ti.

I think Ti and MEK are fine... especially when we're just talking about cleaning..... stuff vapes off in a flash. Not nearly enough time for a reaction.

[Idris Icabod]

I did a fairly intense albeit short scouring of teh googelz and found some kinda obscure NASA studies on halogenated compounds and titanium, but I couldn't find anything related to MEK and Ti. Except examples of using MEK to clean Ti.

I think Ti and MEK are fine... especially when we're just talking about cleaning..... stuff vapes off in a flash. Not nearly enough time for a reaction.

I'm an organic chemist so no knowledge about metallurgy but MEK probably has the very similar properties and reactivity as acetone and there is no way that acetone does anything to Ti tubing. Heck, I cleaned the old decals off my Moots a few years ago with acetone and the thing hasn't broken yet!