Finally finished city bike!!

I finally finished the city bike! Fenders, Brooks saddle and some fine Nitto bars. It also features a SRAM Spectro 7 internal hub. I think on future bikes, I'll spec the Shimano Nexus hub with roller brakes. Much cleaner and no rim brake dirtiness. Other than that, the bike turned out well. It should make a good commuter for San Francisco.

Long time, no post....

Sorry about the delay in posting. Its been a long time. But, I've quit my job and have been going to school full time at California College of the Arts in San Francisco studying industrial design. What an amazing place. I'll try to post some of my bike related work here once in a while.
In the meantime, here's a little frame I finished up this winter. I handcut the dropouts from 4130 3/8 plate steel. The headbadge is cut from stainless, i forget which alloy. It cut easily anway. Its bolted into the headbadge with these wee little socket head cap screws.
More to come this summer when I have some time to work on more frames. Untill then, I'll try to catch up on some pics I have in folders that show some more process work.
Another interesting note on this frame. I left the back end of this frame unpainted to try a little something out. I finished the tubes with Fred Parr's Altife Pro and it hasn't rusted yet!! And I live right by the ocean with plenty of salt air and rain. Fine stuff, Mr. Parr.

More lessons than I can shake a stick at....

I've been getting in lots of practice sessions working on my fillet joints. Instead of posting on a regular basis, I've been just spending time with the torch. Fred Parr has been helping me a ton getting everything set-up right. Do yourself a favor: call him. He is incredibly knowledgable. His new Al-Tife metal pre-treatment is incredible. The LFB I've been using just flow's like mad. Wets out on crappy steel like hot butter on a skillet. Its so effective, I've been having to re-learn how to pull a fillet around the joint. (pics to come.)
I've also got some tubes on order as well as some silver. We're getting close, folks.
Frame #1 will be a pixie bike for my buddy, Derek. Something easy to start with, nice small frame, short tubes, strength requirements are pretty minimal.
In the meantime, I'll get some pics posted of my progress. Its not pretty, but its progress.

Go with the Flow....

You'll remember that I got some lugs from Rivendell a while back. These are labelled as "practice" lugs and are sold as seconds at $2 each. Right in my price range.
So, I've been working with these things and they are great!
I start with taking my flexible shaft tool and using a sanding drum, work it around the ID of the lugs to open them up to the proper clearance. You want to open it up just enough so that the tube slides in. This is quite different than needing to force it in. It should just slide in. This tells you that you have .003-.005 clearance. This is important for the capillary action of the molten filler metal.
Once everything is sanded and cleaned up and your tubes are mitered, I fixture it up in my vice and get the torch going. Heating is crucial. However, its pretty easy as the flame does all the work. Your job is to keep your patience and wait. Once the metal is the right color, (depending on your filler, of course,) just drag the rod/wire around the lug edge and imagine using the flame to brush it in.
That's it. Seriously. Its pretty easy.
After cutting a few lugs apart, its amazing to see how the molten filler, (in this case, bronze,) flows right in, and even creates a little internal fillet between the two mitered tubes. Just amazing.
I think my first frame will be lugged.

Stay away from hydrochloric acid!!!!

I received an e-mail from Fred Parr this morning. He's been sending me volumes of advice as I blunder my way through the learning curve of fillet brazing. He's been working with me to help me refine my prep process for the tubes. This is critical and the large part of your time is dedicated tocleaning and preparation. If the prep's not done properly, no amount of welding charm and skill will save you.
His #1 point of advice is: DO NOT use hydrochloric acid to clean your tubes. Hydrochloric acid is found in many cleaners and degreasers. Mr. Parr states that the hydrochloric acid never stops eating the steel. This will ultimately compromise your hard work.
Ok. No hydrochloric acid. Got it.
So, looking around the house and the stores, I found a phosphoric acid cleaner normally used for cleaning the lime and mineral buildup out of coffee pots and humidifiers. So, I made up a weak solution to apply to the mitered ends of my joints. A test peice showed some bubbles, indicating that some sort of reaction was taking place. About 5 minutes in the solution and voila: A nice clean tube, inside and out.
Fred says that this is fine with regard to joint strength and longevity. HOWEVER, phosphoric acid, when heated, creates a nerve agent. Uh-oh. Not good. Now, I had been cleaning this off with a light soap solution. But still, history tells me nerve agents are not good.
So, we're back to the citric acid cleaner and elbow grease. There's just no way around it folks. Steel and its oxides are hard, so get in there and scrub!
Fred Parr has some new metal cleaners and preservatives called Al-Tife. I highly recommend you give him a call. Its far more complicated than just a cleaner and will apparently change the way you fillet braze! I can't wait to give it a try.

New dropouts!

Ok, I spent the past week working on another dropout as well as some more fillets and a lugged joint.
The dropout I did in the usual manner: layout on paper, then stick to metal and start drilling and sawing and filing. This one didn't take as long. About 4 hours start to finish. Still, that's a lot of time with a jeweller's saw. I spoke with Chuck Schlesinger at the NAHBS show in San Jose and he told me to try e-machineshop.com. He said he got his laser cut for about $8 each. Not bad. Once I have a design I like, I'm going straight there.
Speaking of which, the NAHBS show was incredible. I tried taking some pictures, but to tell you the truth, I'm no photographer. It really didn't do it justice. Just google it and I'm sure you'll come up with a better selection. In fact, cyclingnews.com had a nice 3 part photo report on it.
I also had a chance to speak with JP Weigel who had some great advice on fillet brazing. He was very excited and encouraging to hear that so many are trying to build frames. Great guy, I recommend you look him up.
Let me know what you think of this dropout. Sorry the photo is so bad. I'll take some better ones later and repost.

Fillets!

Had a great time this weekend creating fillet joints. With some coaching, proper set-up, fluxes and rods, I'm feeling better and better with each pass. The nervous hand-shake is gone, I'm working through the points on the mitered tube better and overall, I think I'm having about 90% success. I'll post some photo's of work later on, but in the meantime, here's the down-low on my set-up and tips:
1. Use a good flux- this is key. I'm using Fred Parr's Saf-T-9 of which you apply a very thin coat.
2. The tube miters need to be good, really good. If you've used a hole-saw to rough it, clean it up with a file and get rid of inconsistencies. At the temperature which brass flows, it will flow right through any gaps to the ID of the tube.
3. Clean the tubes well. In fact, I don't think they can be too clean. I use emery cloth, then a degreaser such as Mira-Chem, (don't use any cleaners with hydrochloric acid,) then liberal, aggressive brushing with stainless brushes on the OD and ID. I don't know what the stainless is doing, maybe some sort of passivation, but it works.
4. Get it hot but not too hot! The tinning run after tacking is very important in forming that internal fillet. I'm still too conservative when tinning, but I find you actually have to run a little hotter than you think you do. Cool off the flame by backing off the oxygen a little then proceed with your fillet run with a larger rod. Keep the puddle moving, gently filling the puddle to avoid voids and watch the shoreline for temperature indication. If the shoreline is getting too wide, you've got too much heat in the tube. Back the torch off a little and keep moving away from the hot area. Do not dwell too long trying to fix it!
5. Use a bath or pot of hot water to get the flux off the tubes onces they've cooled. Water between 140 and 160 degree will get must of the flux off within 60 seconds. Flux remaining that's heavy with oxides might take a minute or two longer.
6. One more note, if you're practicing and you know its not your best work, move on. Spending an hour filing and sanding won't make it better. In fact, the better your fillet, the less you'll spend on sanding and filling.
Hope this helps. These were some hard-learned lessons for me. Here's an example from Dave Bohm of Bohemian Cycles of what you're shooting for.