1994 Serotta Colorado ATi - and a Lot of DIY Anodizing

[Frankenorange]

I love this thread. It has interesting bits and peices, engineering and some science. I think those stems are ace and wish you could get longer versions. I think 135mm was available, but thats it.

Forgot to say.... there is some good info and a manual on the Disraeli Gears website, for the Precision mech, but maybe you already know that.

 

[MuchAlohaNui]

I love this thread. It has interesting bits and pieces, engineering and some science. I think those stems are ace and wish you could get longer versions. I think 135mm was available, but thats it.

Forgot to say.... there is some good info and a manual on the Disraeli Gears website, for the Precision mech, but maybe you already know that.

Glad you are enjoying some of the aspects thus far. Yeah these stems really are no comparison to others and totally fly under the radar IMO. I think the Dyna-Tech lovers are dialed into them for sure in part because the frames were high quality Ti but the early stems were cromoly and people were demanding a Ti stem. The Retrobike Dyna-Tech appreciation thread is very very very long, but in general, I think no one outside that thread has bothered to look closely. I mean look at the photos...this stem is so unassuming looking it's laughable. Everyone is always talking about their Ringle 3DV and Syncros Cattle Prod stems but in comparison those are very very heavy to these Dyna-Tech stems by a long shot: 189 grams and 224 grams respectively. The Ringle stuff is beautifully anodized for sure. I do though, have a Cattle Prod on my 92' Serotta T-Max which was a factory option, but that bike is also a steel frame and neither here nor there at the moment.

Hey thanks for the Disraeli Gears recommendation and no I was not aware. For anyone else too lazy:
https://www.disraeligears.co.uk/site/home.html
The info on Precision while short, was helpful. I was a bit unsure as to what year/version of a derailleur I had but that website cleared some smoke for me. I anticipated picking up a derailleur and preemptively bought all the spare parts from a recent F/S thread by @thesneaker and he included these two super cool factory manuals by Precision. Like mentioned on the Disraeli Gears website, these manuals look like they were printed at home and assembled very basic. Cool nonetheless.

 

[MuchAlohaNui]

Been experimenting with different etching chemicals that have been mentioned on other forums. The problem with titanium is its very high resistance to corrosion so the ideal scenario would be Hydrofluoric Acid and second best Ammonium Bifluoride, but being in Europe I cannot find either of these anywhere (and not growing up here, more or less not knowing where to look exactly).

I have been able to get my hands on some semi-commercial grade de-greasers which are "supposed" to etch metals, and are really not doing jack squat. I've tried rust removers...no luck.

Do any of you who are in Germany know what household, readily available cleaning chemicals comprise Hydrofluoric Acid? Examples from America are Wink Rust Remover and Lysol Toilet Bowl Cleaner. Without the Hydrofuoric Acid, I cannot get a proper etch on the surface of the titanium...which means muted colors when anodizing.

 

[MuchAlohaNui]

Seems I can get results with using Sulfuric Acid (swimming pool chemicals), but due to fumes is something I would need to do outside for safety reasons. I have been to several hardware stores over the last few days looking at various tile cleaning chemicals, pool cleaning chemicals and drain clog chemicals. The hardest stuff I can find over the counter so far is 30% H2SO4 in pool cleaner. I can decrease etching times by reducing the ratio of distilled water and increasing the temperature of the solution to 90 degrees C or a little higher (so it seems). Likewise, a solution with a pH around 6.8 is ideal.

https://pubmed.ncbi.nlm.nih.gov/16375960/
An order of hierarchy of sorts from best/fastest etching of Titanium to satisfactory/slowest:

1) HF: Hydroflouric Acid i.e. Winks Rust remover @ 1-2.5% concentration to distilled water and works extremely fast
2) 3) HO2C−CO2H: Oxalic Acid i.e. pool pH additive @ 15% concentration to distilled water over several minutes of submersion VIA electroetching...just like how you would anodize titanium in the first place with a cathode and anode
3) SF + APS: Sodium Flouride + Ammonium Persulphate @ 5% SF + 10% APS + 85% distilled water at 27 deg. C for 6 minutes
3) H2SO4: Sulfuric Acid i.e. pool pH additive @ 48% by ratio to distilled water at 90 deg. C time varies
4) NAHSO4: Sodium Hydrogen Sulfate i.e. pool pH additive @ >90% by weight

Still though, Hydrolouric Acid at 2 - 5% concentration would be ideal because the etching is over in less than ten seconds or so, where as a weaker and all be it, safer acid will take several orders of magnitude longer. As always if anyone knows where to buy over-the-counter Hydroflouric, let me know!

 

[Frankenorange]

You are going to get black van'd at this rate with all the chemical googling and purchases . It is like bomb makers bingo

 

[MuchAlohaNui]

You are going to get black van'd at this rate with all the chemical googling and purchases . It is like bomb makers bingo

I use 20 VPN's, spoof other peoples MAC addresses and only post from public wifi. Granted, making a post takes upwards of a half hour to upload and update but yeah, gotta be careful these days.

In all seriousness I am only looking for about a U-haul sized amount. I have a LOT of titanium to try and anodize.

Ok ok, I'll settle with a rust remover german-brand recommendation like the American brand Winks that has a few % HF, if possible. Though I am suspecting some bureaucrat in Brussels has made the decision that rust remover will make the polar bears cry and is verboten.

 

[rigidftw]

Ok ok, I'll settle with a rust remover german-brand recommendation like the American brand Winks that has a few % HF, if possible. Though I am suspecting some bureaucrat in Brussels has made the decision that rust remover will make the polar bears cry and is verboten.

Looks like hydrofluoric acid is not sold to regular citizens and is only available for commercial purposes. You'd need to provide information that you're running some sort of business to be able to order it online.

 

[MuchAlohaNui]

Looks like hydrofluoric acid is not sold to regular citizens and is only available for commercial purposes. You'd need to provide information that you're running some sort of business to be able to order it online.

Are you located in Germany?

 

[rigidftw]

Are you located in Germany?

Yup.

 

[MuchAlohaNui]

Small update: I received after much delay my new scale. Max weight of 500 grams, but also reads to 1-hundreth of a gram. I was looking for better resolution from my wife's baking scale and with some of the lighter aluminum and titanium bolts the measurement would wander and never settle. First weight is new scale, second is the kitchen scale. BOLD is the lighter reading and all in grams of course. The old kitchen scale was rounding up or down to the nearest whole number:

Cycle Dynamics titanium 8-spd cassette, lock ring and spacers:
146.35 / 150

Rock Shox Mag 21 SL (must be weighed by piece due to scale limitation. 1322 grams total with old kitchen scale)

Michael Dengler brake bridge w/cantilever stop and aluminum m6x15 countersunk bolt
159.90 / 160

Brake post pretensioners (three hole type)
1.56 (3.15 grams total for two) / 3

Titanium m6x20 bolt which hold brake bridge to forks (prior stainless steel were 6 grams ea.)
2.48 / 3 (4.96 grams total for two)

Titanium SRP brake bosses (prior steel were 11 grams ea)
5.61 / 5 (11.22 grams total for two)

Ultimate Machine Co. crown, aluminum 1-1/8" x 200 mm x 3.48 mm wall thickness steer tube, generic star nut & Chris King No-Threads bearing race
358.32 / 358

Titanium SRP m5x20 crown bolts (prior stainless were 5 grams ea.)
2 / 2 (8 grams total for four)

Rock Shox Mag 21 SL non-drive side fork
376.51 / 376

Rock shox Mag 21 SL drive-side fork
390.55 / 391

Rock shox Mag 21 SL weight with new scale: 1312.61 grams

Tech Lite brake levers
106.12 / 107

Delta Aztec brake pads (x4)
67.96 / 68

Titanium no-name wheel bolts, set
28.95 / 29

Paul Thumbies & Shimano Ultegra bar end shifters (148 grams total weight with original stainless steel hardware weighed with kitchen scale)

Paul Thumbies
53.96 / 54

Paul Thumbies bolts m5x20 mm x4 (prior stainless steel were 5 grams ea.)
1.18 / NA

Shimano Ultegra bar end shifters w/ square adapters
69.69 / 71

Paul Thumbies & Shimano Ultegra bar end shifters with new scale: 128.37

Proshift long-cage derailleur
184.76 / 185

Raleigh Dyna-Tech Titanium 1-1/8" x 130 mm stem
103.44 / 106

Raleigh Dyna-Tech Titanium m6x20 mm x2 (prior stainless steel were 7 grams ea.)
2.89 / 3

Nosler 32h front hub
73.59 / 75

Onza Porcipaws, clear, no bar end plugs
51.74 / 52

Schmolke TLO handlebars
73.58 / 74

Titanium 68 mm x 122 mm NO NAME/MYSTERY bottom bracket with cups x2, lock rings x2 & bearings x2
164.68 / 165