Titanium Frames and anti seize

[timsmcm]

What causes a carbon seatpost to weld solid into a titanium frame. I have had one do it and several riding buds that have the same thing happen. I had to cut mine out and it was in less than a year, or at least that is what the person told me that I bought the bike from. Lost out on that 250.00 post. What is the best doodoo to put on that joint?

[GOTHBROOKS]

not titanium related, but i found that using silver antiseize instead of grease in alu bb30 shells made for creak free riding. both road and mtb.

[Kontact]

Originally Posted by 11.4

Galling isn't a process of chips wedging. The metal has to be under such pressure or heat that it flows -- it literally welds. What does happen sometimes is that the metal distribution is uneven and you get too much metal and not enough grease. At that point it's just like metal filings in the oil in your Toyota. It jams threads, but isn't a true case of galling. Not good.

It is galling, and it doesn't require large amounts of environmental heat - just high localize pressures on naturally passivated metals like Ti, SS and aluminum. If there are screwed together with much friction (under lubricated, rough surfaces), the crusty, hard surface layers fracture away leaving pits that can fill with the chips and stick.

I've seen this personally on an aluminum cup that had no corrosion but a lot of thread chipping when I unscrewed it from a Merlin. There was only grease present in the BB.

Here's a good industry article about it:
https://www.boltdepot.com/fastener-i...d-galling.aspx

Anti-seize, which has particulate that acts as little bearings in the grease, definitely helps prevent thread galling. All types of anti-seize will decrease galling.

galvanic corrosion between titanium and aluminum alloys is definitely a thing.


http://blackmtncycles.com/grease-is-noble/

You are correct, I was wrong. So what happened here?


Titanium will not corrode from galvanic corrosion, but a large chunk of Ti with a smaller piece of aluminum is a likely way for it to happen. This is the best industry article I could find:

https://www.azom.com/article.aspx?ArticleID=1241

Long story short, copper based anti-seize makes things worse, because the copper is pretty reactive, but it is more noble than the aluminum. Which is part of why the BB in the article corroded - of the three metals, the aluminum was definitely the sacrificial anode.

For years I've been using at home and at the shop the little tubes of Permatex. Many don't even say what type of anti-seize they are, but the gray stuff is aluminum based for use with aluminum engines. Apparently, aluminum based anti-seize will act as a sacrificial anode when used with aluminum, probably because the aluminum part in anodized. I was using it because it was much cheaper than Ti Prep, and easier to find than copper based formulas, but it appears to be what might be the best of the common choices.


If I had to guess from everything I've read tonight, I would say the best possible anti-seize for aluminum parts in Ti or SS frames would be either zinc or magnesium based formulas, because galvanic effects will eat those particles before the slightly more noble aluminum. These aren't common because zinc and magnesium aren't so great for engine temperatures, so they are considered very specialized.

Teflow tape can't hurt, either. But I find that it usually is cut by the threads, so it can only do so much.


From the articles I was reading from the marine industry, the main way to prevent galvanic corrosion isn't the kind of lube used between the metals, but how well the anodic metal is protected from water. That means paint and grease covering the outside of the aluminum so the flow of water over it doesn't create a current.

Which makes me wonder if one of the main reasons the BB in the article corroded so badly is because of the huge amount of exposed, uncoated and ungreased aluminum that Hollowtech II cups have hanging outside the frame. They are almost like galvanic antennas attracting the most electrical potential from rain and sweat, but sending that current to where the cathode is - in the frame threads.

I would bet that the worst BB corrosion is with external BBs and copper antiseize.

But I would not be surprised if the worst "cold welded" parts are those that first galled during assembly (or from wiggling during use after being under torqued), and then corroded the chips in place after the anodized surface was broken away increasing the conductivity.


Overall, I would much rather use anti-seize than not because it prevents galling. If the BB cups corrode but the Ti threads are in good shape, the BB will still unscrew and be pretty cheap to replace.

[11.4]

Originally Posted by Kontact

It is galling, and it doesn't require large amounts of environmental heat - just high localize pressures on naturally passivated metals like Ti, SS and aluminum. If there are screwed together with much friction (under lubricated, rough surfaces), the crusty, hard surface layers fracture away leaving pits that can fill with the chips and stick.

I've seen this personally on an aluminum cup that had no corrosion but a lot of thread chipping when I unscrewed it from a Merlin. There was only grease present in the BB.

Here's a good industry article about it:
https://www.boltdepot.com/fastener-i...d-galling.aspx

Anti-seize, which has particulate that acts as little bearings in the grease, definitely helps prevent thread galling. All types of anti-seize will decrease galling.



You are correct, I was wrong. So what happened here?


Titanium will not corrode from galvanic corrosion, but a large chunk of Ti with a smaller piece of aluminum is a likely way for it to happen. This is the best industry article I could find:

https://www.azom.com/article.aspx?ArticleID=1241

Long story short, copper based anti-seize makes things worse, because the copper is pretty reactive, but it is more noble than the aluminum. Which is part of why the BB in the article corroded - of the three metals, the aluminum was definitely the sacrificial anode.

For years I've been using at home and at the shop the little tubes of Permatex. Many don't even say what type of anti-seize they are, but the gray stuff is aluminum based for use with aluminum engines. Apparently, aluminum based anti-seize will act as a sacrificial anode when used with aluminum, probably because the aluminum part in anodized. I was using it because it was much cheaper than Ti Prep, and easier to find than copper based formulas, but it appears to be what might be the best of the common choices.


If I had to guess from everything I've read tonight, I would say the best possible anti-seize for aluminum parts in Ti or SS frames would be either zinc or magnesium based formulas, because galvanic effects will eat those particles before the slightly more noble aluminum. These aren't common because zinc and magnesium aren't so great for engine temperatures, so they are considered very specialized.

Teflow tape can't hurt, either. But I find that it usually is cut by the threads, so it can only do so much.


From the articles I was reading from the marine industry, the main way to prevent galvanic corrosion isn't the kind of lube used between the metals, but how well the anodic metal is protected from water. That means paint and grease covering the outside of the aluminum so the flow of water over it doesn't create a current.

Which makes me wonder if one of the main reasons the BB in the article corroded so badly is because of the huge amount of exposed, uncoated and ungreased aluminum that Hollowtech II cups have hanging outside the frame. They are almost like galvanic antennas attracting the most electrical potential from rain and sweat, but sending that current to where the cathode is - in the frame threads.

I would bet that the worst BB corrosion is with external BBs and copper antiseize.

But I would not be surprised if the worst "cold welded" parts are those that first galled during assembly (or from wiggling during use after being under torqued), and then corroded the chips in place after the anodized surface was broken away increasing the conductivity.


Overall, I would much rather use anti-seize than not because it prevents galling. If the BB cups corrode but the Ti threads are in good shape, the BB will still unscrew and be pretty cheap to replace.

Thread chipping happens for many reasons, and is no indication of galling per se.

And on the last comment ("Overall, I would much rather use anti-seize than not because it prevents galling. If the BB cups corrode but the Ti threads are in good shape, the BB will still unscrew and be pretty cheap to replace."), the point is confusing galling in the first sentence and corrosion in the second. if bottom bracket cups corrode, the oxides they form typically tighten the clearances in the threading to the point that the bottom bracket is locked in place. This is the classical example of a bottom bracket that has to be sawn out of a shell, and is equivalent to a seat post needing the same treatment.

[AngryScientist]

Originally Posted by Kontact

But I would not be surprised if the worst "cold welded" parts are those that first galled during assembly (or from wiggling during use after being under torqued), and then corroded the chips in place after the anodized surface was broken away increasing the conductivity.

yes, this is it exactly. chris king bottom brackets seem to suffer this the worst. i assume they put some surface treatment on the alloy to prevent corrosion, but it is scraped away largely during installation, leaving a perfect surface for conductivity and a relatively large surface area.

i still maintain the best practice, especially if the bike is used in wet conditions is to use a heavy coat of good grease, which serves the purpose of lubricating the threads for install - as well as the big gobs that are left for a sort of barrier against moisture migration along the threads. Pull and re-lube often. the specific interval of "often" is something to be determined by trial and error.

[Clancy]

First, this forum is overwhelming in its useful information.

Second, this forum is overwhelming in the amount of information. Often contradictory.

So, for reasons of simplicity, is this very basic summary accurate?

When assembling X into Y, use lots of high quality grease.

Disassemble, clean, reapply lots of high quality grease, and reassemble often.
( 1X to 3X a year depending on riding conditions)

Anti-seize is not necessary - Use a high quality grease.

Simple and accurate?

Or can it not be simpled down that much?

[tylercheung]

Not having a whole lot of experience w/ Ti frames...but I would assume Park Tool anti-seize would be formulated for the most common bottom bracket in use today? Or is it always dangerous to "assume"

[Kontact]

Originally Posted by 11.4

Thread chipping happens for many reasons, and is no indication of galling per se.

And on the last comment ("Overall, I would much rather use anti-seize than not because it prevents galling. If the BB cups corrode but the Ti threads are in good shape, the BB will still unscrew and be pretty cheap to replace."), the point is confusing galling in the first sentence and corrosion in the second. if bottom bracket cups corrode, the oxides they form typically tighten the clearances in the threading to the point that the bottom bracket is locked in place. This is the classical example of a bottom bracket that has to be sawn out of a shell, and is equivalent to a seat post needing the same treatment.

I don't know why you would be so immediately dismissive of boltdepot article about thread galling. I've found plenty of references to it in a range of industries. Why do you know Ti BBs are immune?


As far as the cups corroding, you'll note that in this article the cups did come out. They weren't "cold welded" to the frame and the frame threads weren't damaged. You'll also note that the worst damage wasn't in the center of the thread but mainly at one exposed end.


Anti-seize prevents thread galling better than grease. As long as the anti-seize doesn't contribute to galvanic corrosion (like copper based ones do), then you are getting superior protection from anti-seize than grease. And if you use an anodic anti-seize, you are getting the best possible protection from both thread galling AND galvanic corrosion.

[Clancy]

Originally Posted by Clancy

First, this forum is overwhelming in its useful information.

Second, this forum is overwhelming in the amount of information. Often contradictory.

So, for reasons of simplicity, is this very basic summary accurate?

When assembling X into Y, use lots of high quality grease.

Disassemble, clean, reapply lots of high quality grease, and reassemble often.
( 1X to 3X a year depending on riding conditions)

Anti-seize is not necessary - Use a high quality grease.

Simple and accurate?

Or can it not be simpled down that much?

“Not having a whole lot of experience w/ Ti frames...but I would assume Park Tool anti-seize would be formulated for the most common bottom bracket in use today? Or is it always dangerous to "assume" “

Two questions basically the same.

Answers?

[zank]

When I worked at Seven, we always said to use Phil Wood grease. That will be my same recommendation on my ti frames as well.

[Cicli]

Originally Posted by Clancy

“Not having a whole lot of experience w/ Ti frames...but I would assume Park Tool anti-seize would be formulated for the most common bottom bracket in use today? Or is it always dangerous to "assume" “

Two questions basically the same.

Answers?

Park antiseize is just that, Antiseize. Nothing special.

[oldpotatoe]

Originally Posted by Clancy

“Not having a whole lot of experience w/ Ti frames...but I would assume Park Tool anti-seize would be formulated for the most common bottom bracket in use today? Or is it always dangerous to "assume" “

Two questions basically the same.

Answers?

The operative term with any metal on metal attachments on bikes is frequency of taking apart, cleaning and re applying the 'stuff', whatever that stuff is. I use antisieze on Moots ti seatpost in my Moots...in BB, I use grease...stainless bolts(like bottle cage bolts), antisieze. BUT grease is fine, antisieze is fine(altho hard to wipe off fingers)...but applying some 'stuff', that 'may' be formulated for bikes(most not, just repackages automotive stuff, add $ please), and then just forgetting about it, thinking you are covered, is a mistake, IMHO, of course.

[Mikej]

If you ever got ti anti seize on your couch, you know it never comes off. That’s my reasoning-

[Rusty Luggs]

I use aluminum based anti-seize (Permatex) on threaded fasteners. All of them. That include things I thread into Ti bikes, including bottom brackets.

I use grease on things that rotate, like bearings and bushings.

I got away from lubing threads with grease long ago, particularly after seeing threaded stuff exposed to the elements did much better from a frozen thread standpoint if lubed with anti-seize. I only use grease if I don't have anti-seize available, since it's better than nothing.

If you know about galvanic corrosion, you wouldn't pair up copper and aluminum. Copper based might be fine if threading Ti into Ti.

In the world of industrial maintenance, nobody lubes threads with grease, it is always anti-seize.

[11.4]

Originally Posted by Kontact

I don't know why you would be so immediately dismissive of boltdepot article about thread galling. I've found plenty of references to it in a range of industries. Why do you know Ti BBs are immune?


As far as the cups corroding, you'll note that in this article the cups did come out. They weren't "cold welded" to the frame and the frame threads weren't damaged. You'll also note that the worst damage wasn't in the center of the thread but mainly at one exposed end.


Anti-seize prevents thread galling better than grease. As long as the anti-seize doesn't contribute to galvanic corrosion (like copper based ones do), then you are getting superior protection from anti-seize than grease. And if you use an anodic anti-seize, you are getting the best possible protection from both thread galling AND galvanic corrosion.

I am saying that titanium bottom brackets are not immune to corrosion. But I'm saying that they don't undergo true galling. The example you cite, with the damage at one exposed end, is characteristic of corrosion -- corrosion typically doesn't happen without exposure to air. And while in this particular case it was possible to spin the bottom bracket out, in many cases it isn't and one is trying to figure out how to cut the cup out of the shell (or the seat post out of the seat tube).

Anti-seize does prevent galling better than plain grease but for different reasons -- the metal flakes have a lubricity that allows the metals to slide against each other. The issue here is that what's happening in a bottom bracket or seat post is typically corrosion. Galling occurs as soon as you've applied heat or pressure to the two metals in contact, so you would have a galled and locked up bottom bracket as soon as you had threaded it in. That's not what people typically find. What you find is induced by corrosion over time and that is why the bottom bracket tends to thread in easily when installed but is locked up a year later.