# Did anyone else notice this? Guru/ti welding?



## Walt (Jan 23, 2004)

Factory Tour ? Guru Cycles, Part 3: Titanium Frame Building, Painting and Finishing

You ti guys - is this amount of color/O2 contamination ok? I know very little about working with ti but I've been told blue/black/grey anywhere = frame in the trash, start over. Obviously these guys are professional builders - am I crazy to think the contamination looks scary?

-Walt


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## RCP FAB (Jun 15, 2011)

I haven't welded Ti in years, and never any frame work, but I did quite a bit of Ti and one of the welding shops I worked at. We were "allowed" a slight straw color without catching any crap. Anything blue/purple/green/whatever was unacceptable.


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## smudge (Jan 12, 2004)

That amount of color is not OK at all.

This amount of color is what you need.


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## Walt (Jan 23, 2004)

Yeah, that's what I thought. So what were they thinking letting those pictures get out? Do they not KNOW they're doing a bad job? 

I like this line in the article, too: "They use diameter rather than butting to doctor the stiffness of the frame. They say this gives the desired result without adding the additional weight and complexity of butting."

WTF?!? I really hope that was just a misquote or misunderstanding...

-Walt


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## Testmule (Jul 27, 2013)

I think they just slipped up letting those pics get published. There has to be someone in house that knows what their doing - er maybe not&#8230;
I am just getting back into some ti bikes after a twenty year hiatus. When I started I self taught myself through an extensive technical library at a local college, and the information I learned from was intended for aircraft standards.

Colour isn't good and indicates loss of shielding and would be rejected in the aircraft industry. I think some bike builders get away with a lot in the industry, because most failures of titanium frames are usually from abuse or crashes - the stresses on a bike frame, in most cases, is much less than in an aircraft. I am still in contact with happy customers after twenty years.

When I built my first frames I was buying the 3/2.5 tubing from Ancotech in Detroit MI, and got a full tour of the plant. The tubing would come in wooden crates and looked like a case of guns. It also was aircraft certified and came with a mound of paperwork.



Walt said:


> Yeah, that's what I thought. So what were they thinking letting those pictures get out? Do they not KNOW they're doing a bad job?
> 
> I like this line in the article, too: "They use diameter rather than butting to doctor the stiffness of the frame. They say this gives the desired result without adding the additional weight and complexity of butting."
> 
> ...


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## seat_boy (May 16, 2006)

So they're just using straight gauge tubes instead of butted... not the lightest way to manage the stiffness of a frame, but probably quite a bit more cost effective.



Walt said:


> Yeah, that's what I thought. So what were they thinking letting those pictures get out? Do they not KNOW they're doing a bad job?
> 
> I like this line in the article, too: "They use diameter rather than butting to doctor the stiffness of the frame. They say this gives the desired result without adding the additional weight and complexity of butting."
> 
> ...


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## Walt (Jan 23, 2004)

What I meant was that they said the straightgauge tubes are *lighter* as I understand it...


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## unterhausen (Sep 28, 2008)

the standard in the bike industry is to make things the way you want to make them and then come up with some bogus reason why it's ok, if not better. As time goes on, good technical information has seemed to diffuse into cycling, but you can expect people to try to feed you horse manure as well.


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## dacosta (Jul 23, 2010)

Looks like just surface contamination to me. The oxidation should buff out with a wire brush and some elbow grease. Its difficult to weld those tight corners with out a little surface contamination. Personally I would add more post gas, and buff out the contamination before continuing to weld. Also I would have buffed out the weld before taking the picture. If the contamination is so deep that the wire brush doesn't buff it out then you got problems. 

Fooly


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## car bone (Apr 15, 2011)

Walt said:


> Factory Tour ? Guru Cycles, Part 3: Titanium Frame Building, Painting and Finishing
> 
> You ti guys - is this amount of color/O2 contamination ok? I know very little about working with ti but I've been told blue/black/grey anywhere = frame in the trash, start over. Obviously these guys are professional builders - am I crazy to think the contamination looks scary?
> 
> -Walt


That color is ok imo. Its the first 2 colors that appear after heating. kinda.

If you have a piece of ti you can just heat it at the end with a propane torch and then you see the colors and their spread, from hottest to coldest. Remember to sand it and degrease it first. for fun you can put a fingerprint (lipides/contaminant) somewhere and see how that turns out.

The colors allowed are different for different applications and ti varieties. Even though that we saw above is not optimal, its not bad. Id say that frame will last for at least 10 years. Even frames that are severely colored (really really unaccepable colors) hold up just fine for a at least a few years. The ti gets a bit brittle, or a lot brittle but it could still be strong and durable enough to last many years.

Even if its really dark and purple and all imaginable colors it will polish right off since the destructive/constructive interference is like a few wavelengths of light thick Interference (wave propagation) - Wikipedia, the free encyclopedia its still ruined though.

I have a feeling those colors are less than most makers, or on par. The reason for colors is speed of fabrication, it all has to go so fast. Me and my father discussed this and he told me "no one is ever gonna use the long (30s) post gas when welding a bike" and he's probably right (he is a welder), most people probably just weld it up like that or a bit worse and polish/blast it off, no one will ever know. This is obviously the wrong way, but i think its very common. If its not going up in space and no one is there to verify it people take short cuts.

I would ride that one. but not much more color than that. its very light blue and light brown. At least the quality is known with this brand.


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## car bone (Apr 15, 2011)

this is severe color for artistic reasons but still those colors turn up quite quickly, after that it gets lighter again.















electrical anodized, not as punchy colors but they follow that line from the least voltage to the most, its the same with heat, but its much harder to control the colors from heat, green for example is hard to get, but easy with electricity.















Brown here is the coldest, followed by the deep purple and the light blue. the hottest part here is the light colored parts in between the brown ones, thats where the flame was put. and that last pic is taken in daylight in a window facing the sun, camera whitebalance set to daylight so its 100% representative color wise if your monitor is calibrated that is. edit: you have to click on the last to see it for some reason.


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## smudge (Jan 12, 2004)

car bone said:


> I have a feeling those colors are less than most makers, or on par. The reason for colors is speed of fabrication, it all has to go so fast. Me and my father discussed this and he told me "no one is ever gonna use the long (30s) post gas when welding a bike" and he's probably right (he is a welder), most people probably just weld it up like that or a bit worse and polish/blast it off, no one will ever know. This is obviously the wrong way, but i think its very common. If its not going up in space and no one is there to verify it people take short cuts.
> 
> I would ride that one. but not much more color than that. its very light blue and light brown. At least the quality is known with this brand.


OK is a relative term I guess. At best, they're managing their failure rate vs. speed of manufacture and at worst they don't know that it's bad. Color isn't the only no-no shown in those photos. It's also obvious that the oxides weren't cleaned off of the tubes before they were welded. You can have a weld of acceptable color and the oxides will still be buried in the embrittled weld. You can simulate this by welding over colored ti. The color goes away but where did it go? It's being driven deeper into the weld.

What's shown in those photos isn't OK.


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## G-reg (Jan 12, 2004)

Guru said:


> From Tony Giannascoli, Founder: Please allow us to chime in on the posts regarding Guru's welds. Guru has been welding titanium frames for more than 10 years already and we take great pride in our craftsmanship and in our weld quality. We were pleased when Tyler accepted our invitation and we allowed him to snap pictures of anything he wanted as we are transparent and have nothing to hide.
> 
> Weld zone discoloration is inevitable when welding outside of an inert chamber. In the bicycle industry, since weld bead aesthetics are important, frames are welded outside of an inert chamber but steps are taken to ensure the integrity of welds. Firstly, the interior of the frame is purged of all oxygen using Argon gas. Then, a specially designed cup which diffuses Argon gas evenly is used to purge any oxygen from the outer surface of the weld. Inevitably, some discoloration will be evident with this technique. It is only a few microns thick and can be easily removed using scotch brite to finish the surface (photo above).
> 
> Note that we've had our welds tested by independent laboratories using x-rays and micrographs. In all cases, the results demonstrated very low levels of porosity and high levels of purity with virtually no contamination. The ultimate test for our welds is fatigue and impact testing which we regularly conduct at Guru. These tests demonstrate that when frames are brought to the point of rupture due to excessive abuse, the welds never break. Furthermore, we have many clients who have been riding their Guru-made titanium frames for well over 10 years without any incidents (Editor's note: They added via phone that they haven't had to warranty a single titanium frame). This is the true testament to the quality of our titanium frame construction.


BR post was updated...


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## zank (May 19, 2005)

Bike radar did a tour of the Dean factory and published pictures of ti welding that were just as bad. Pretty sad. It looked they were using a #7 cup and outrunning their coverage.


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## davesauvageau (Jan 8, 2010)

Minus the horrible music, Seven Cycles' factory tour is pretty good. Her welds look very clean, can't tell if it is Ti, could be stainless too:
Seven Cycles - Factory Tour - YouTube

Most Ti builders pay special attention to contamination, chemically cleaning tubesets and handling them with cotton gloves to avoid contamination. Apparently Lynskey doesn't give a hoot about it in this video:





Where's Rhody when you need him! Groovy Cycleworks, get in here and drop some knowledge!


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## car bone (Apr 15, 2011)

smudge said:


> OK is a relative term I guess. At best, they're managing their failure rate vs. speed of manufacture and at worst they don't know that it's bad. Color isn't the only no-no shown in those photos. It's also obvious that the oxides weren't cleaned off of the tubes before they were welded. You can have a weld of acceptable color and the oxides will still be buried in the embrittled weld. You can simulate this by welding over colored ti. The color goes away but where did it go? It's being driven deeper into the weld.
> 
> What's shown in those photos isn't OK.


But remember the color only indicate that the very surface has been oxidized, now how deep it goes. the diffusion depth is unknown here, gas diffuse into the ti faster and deeper the hotter it gets and the longer the soak, similar to carburizing/nitriding steel in a Carbon containing atmosphere. But it is a sure sign that at least the surface has been oxidized to some degree.
And this could have been avoided. Preferably they should have welded (and all other processes involved) this to aerospace standards, but I guess very few actually do.


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## whydomylegshurt? (Jul 28, 2004)

If you charge $4500 for a ti frame you better weld to the best standard available. Seeing as NASA, Miller, AWS and ASM all agree that no color past dark straw should be seen in the weld bead I feel Guru has failed. Both the drop out and the BB show discoloration in the weld, not just the HAZ. They didn't even prep the tubes to remove the oxide layer.


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## car bone (Apr 15, 2011)

I'm not arguing there. 4500??? lol wtf. for 4500 there shouldn't even be straw. It should be nothing nothing nothing as shown in one of the first pics.


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