Bicycle Mechanics - Ti build concern

So I am about to build up my 1st Ti frame, and I remember reading many years ago that the BB could "seize" if not properly treated.

Is this really a problem? What "anti-seize" product should I use?

Any other Ti issues?

Thanks for any help.

Any 2 dissimilar metals will eventually seize. With that said and to answer your question. When I install a BB I wrap the threads with Teflon plumbers tape. I have not had a problem with my BB's seizing. I have worked on some bike that did have the BB seized. Looked like the threads were not treated with anything, just installed dry. Any new BB you get will have a small amount of grease on the threads from the MFG.

its called anti sieze and you it it at the auto parts store. its messy and gets all over the place

I have a small tin of anti seize I use for threads on spokes, when building.. , grease with a powdered metal in it ,

mess not so bad, but I don't have an all White living room either.

Make it easy on yourself and cheap by doing what Kycycler said and use the white Teflon plumbers tape (You can use yellow teflon gas tape too, it's just a mil thicker so you would wrap 1 to 2 times). It's fast, easy, no mess, and last forever...at least until you remove the BB. Just wrap the threads as you would with pipe, in the same direction as the BB will screw into, wrap about 2 to 3 times fairly tight, cut don't tear the tape,

I use a graphite paste called Never Seize. You buy it at plumbing supply stores.

The problem with titanium alloys is unless finely polished/ burnished they have a nasty tendency to behave in an abrasive way when something slides over the interface. The bottom bracket in a frame are likely tapped, and screwing the cup in dry will likely cause instant gauling and microwelding. The parts won't get a chance to be damaged from corrosion or eventual solid state diffusion.

Grease or antiseize are absolutely necessary.

Not to disagree with the strong advice to use some sort of lube/antiseize,
not just with Ti but other metals and any inserts in CF frames,
I apparently got away with an Al seat post in my Teledyne frame and Phil
BB which were both left in the frame in the basement from '76 to '99 when
I took it off the hanger and rebuilt with castoff 8spd gear. Phil bearings were
seized up, but a popoff of the seals, wash out and relube fixed that.
One diff: frame was anodized.

Thanks guys -
I would never install BB dry.
Like the idea of teflon tape and a very small amount of grease on top.

1 or the other

Wildwood, I also suggest that you chase and face the BB shell prior to installing the BB. I haven't used teflon tape, though it sounds good, but I have used anti sieze and regular wheel bearing grease without any problems with my aluminum frames.

Brad

Wildwood, I also suggest that you chase and face the BB shell prior to installing the BB. I haven't used teflon tape, though it sounds good, but I have used anti sieze and regular wheel bearing grease without any problems with my aluminum frames.

Brad

With titanium, he'll likely not be able to chase and face the bottom bracket. Not many shops handle the tools to do that on Ti and the cost is waaay prohibitive for the home mechanic.

Use anti-sieze on Ti.Teflon tape should be OK,Ti is really not that abrasive compaired to other alloys,like SS.

Just for the record,you CAN cut Ti with HSS,all day long.I repeat,you DO NOT need carbide/diamond to machine Ti.There is no Ti that is anywhere near as hard as HHS.

If you think you can spin/feed HSS fast/hard enough to burn the edge of the tooling by hand,more power too you.

Use anti-sieze on Ti.Teflon tape should be OK,Ti is really not that abrasive compaired to other alloys,like SS.

Just for the record,you CAN cut Ti with HSS,all day long.I repeat,you DO NOT need carbide/diamond to machine Ti.There is no Ti that is anywhere near as hard as HHS.

If you think you can spin/feed HSS fast/hard enough to burn the edge of the tooling by hand,more power too you.

I could find no one in my bicycle crazy area that was willing to risk their tools on a titanium frame. I called about a dozen shops and each one said the same...Nope.

Ti is generally SOFT, it has other good properties, like strength and corrosion free, but it's a soft material that can be cut easily like any other steel.

For a good lecture about materials check matweb.com
For example Ti alloy (http://www.matweb.com/search/DataSheet.aspx?MatGUID=820e59b4df734877842229181d104acc) compared to some medium carbon steel (http://www.matweb.com/search/DataSheet.aspx?MatGUID=61e5cbeb3ddc4d76a2b5d3e19cdd0341)

Ti is generally SOFT, it has other good properties, like strength and corrosion free, but it's a soft material that can be cut easily like any other steel.

For a good lecture about materials check matweb.com
For example Ti alloy (http://www.matweb.com/search/DataSheet.aspx?MatGUID=820e59b4df734877842229181d104acc) compared to some medium carbon steel (http://www.matweb.com/search/DataSheet.aspx?MatGUID=61e5cbeb3ddc4d76a2b5d3e19cdd0341)

I have to repectfully disagree with your statements about Ti being soft and easy to cut. There are several issues that make Ti difficult to cut. I have designed several Ti parts and have supervised their machining and it is far from a routine process.
1. It does not conduct heat very well, so the cutting zone must be continuously cooled to keep the temps (can easily exceed 2000 degrees F) from ruining the cutter. Most LBS can't easily accomplish this.

2. Ti work hardens so as you cut the material gets tougher and tougher to cut, which also dulls the cutting tool.
3. Ti is springier (more elastic) than steel so it tends to deflect under the force of the cutting tool, which increases friction, and it turn temperature, which increases tool wear.

I don't blame the LBS a bit for refusing to chase Ti BB threads. If I had an expensive pair of chasing taps, I wouldn't want to take a chance on ruining them on a Ti frame.

First, a good quality Ti frame should have it's bb shell properly faced and the threads cleanly made by the manufacturer. I have three Litespeed frames and all have been easy to install the bottom brackets with no further preparation.

Second, Litespeed says plain grease on the bb threads is sufficient to prevent seizure or galling. I've used grease, anti-seize and teflon tape all with good results. I prefer the tape as it's easy to use and not nearly as messy as anti-seize.

Katzman is sort of right, if you are machining in modern high speed CNC machining centers with spindle speeds in the hundreds to thousands of rpm or depth of
cut in the 0.1" or greater range, but clearly hand reaming a BB shell or chasing threads at 3-5 rpm with adequate lube is not going to raise the temp of the cutting
edge more than 3-5D F, probably less and quality HSS tooling is more than up to the task. OTOH Hillrider is right, US made, name brand Ti frame is going to have
had the BB faced and threading cleaned in the course of manufacture. Mainland chinese frames ??? who knows. Ti, even heat treated 6AL4V is not a super alloy
or usable as a cutting tool grade material.

There is a reason that tool makers create special taps for tapping titanium. These taps typically have larger, frequently spiral-cut flutes and grinding away of the trailing edge of thread. This helps deal with chips galling with the parent material and clogging the tap. Once this happens the tap won't turn and can get stuck in the work piece. There are also special cutting fluids for use on titanium. I'm not doubting that in the hands of an experienced machinist at a shop with titanium experience, that tapping titanium is not a problem. For the average bike mechanic at the local bike shop, using a tap designed for tapping steel - not so much! Most shops in the ti manufacturing business prefer to cut threads using a single point method.

And don't fool yourself. Even hand feeding a tap can create very high localized temperatures at a microscopic level - high enough to create a spontaneous weld between particles. That is what causes the galling effect.

some info on drilling and tapping titanium (http://www.timet.com/fab-p18.htm)

Yikes...I built up my Ti bike in August and didn't even think about this issue. This thread may have just saved me a bunch of money, if it's not too late to fix it.

The other annoying about machining Ti is its flexibility throws off your cuts. It flexes away from the tool and springs back. So you have to cut in smaller increments with many repetitions to get the dimensions right.

The other nice thing about the teflon plumbing tape is you can use it to fill the gap between the BB-shell and BB-cups. The tolerances are high and there's enough room for the cups to move vertically within the threads, leading to A LOT of annoying creaks. I'll usually use anywhere between 3-6 wraps of the tape. I typically start at 4 layers and feel how it goes in. If moves easily with minimal force from the wrench, I'll start over and use 5 layers. If it's too tight, I'll use 3 layers. etc.