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Hi fellas (and lurking ladies),I have been welding bike frames here in the Phoenix area for about the past nine or so years. Its not the only thing I do by far, but I get about two or three a month. Most are aluminum ones. I am aware that these are heat treated and that the welding affects the temper. I compensate by always plating cracks or breaks on both sides. So far not one has returned to me or complaints of breaks. However this doesn't mean that they didn't break, only that I was never informed.I did have one person several years ago put a craigslist post (where I post my service) promoting my service. He reported that the repair on his bike was still holding up after two years on the road. I plate all repairs in one form or another regardless of base metal by the way.However, recently I have been thinking that I would like to be able to heat treat parts (or frames) to restore hardness and am in the process of locating some local services that do this. My question is: Has anyone else done this before? Is it cost effective? Some bike frames I repair are obsolete and no longer available except on the use market. So repair or fabricating from scratch is the only solution.Some of my customers are hard core mountain bikers and I think for them it is important to be able to restore the hardness. Swing type chain stays are subject to cracks and I repair and plate these often. I would like to harden these maybe as a matter of practice. Any thoughts on this? Anyone been down this path before?Finally, in my old age (I'll be 65 this year), I want to slide away from the heavier aspects of the welding and decided to specialize in bike frame repair and possibly building. I have ordered some plans for a bike frame jig and for a cool recumbent trike made from off the shelf parts and welded steel frame. I am also investing in a bike repair stand to simplify my life. I am aggressively moving in this direction and have setup a Facebook page to promote this work. "Bike Frame First Aid".My logic is that the biking community will be growing as the years pass and the biking culture spreads. There will be a need for repair services even more so of the metal working type. I would encourage others to explore this too.Thanks for the feedback,Tony
Reply:Nice work! mzank, a member here would be your go to guy with your questions. Hopefully he chimes in, if not send him a PM. One of the best bike builders around!I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:I don't know that mzank guy but zank is great too.
Reply:@ therrera - echo what weldermike stated about WW member Zank. Zank's at the zenith of custom bicycle fabrication & welding. Aluminum, steel, and titanium frames. Certain he'll jump in to support you. Aloha "Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:i would say it's not economical.i've gotten some heat treat quotes, they were in the hundreds of dollarsand all I wanted to do was take a bunch of 1/4 aluminum bar and anneal it to zero temperI can buy a lot of map/propane torches for what they quoted. http://www.thefabricator.com/article...ation-for-6061maybe if you got a self cleaning oven and rockwool insulation (doesn't burn made of rocks) you could do it one frame at a time,you could also royally screw up an irreplaceable bike frame trying to make it a tiny bit stronger and gain a reputation as someone who pushed the limits and destroyed their customers gear.
Reply:Tony, nice work on the repairs! I think you are the right track with gussetts and doublers. As far as heat treating goes, the grade of aluminum determines how to proceed. Generally, bicycles frames are constructed of 7005 or 6061. If it's 7005, they are aged at 250F for 12 hours. If it's 6061, that's much more involved. The frame is first brought up to 900F and held there for a predetermined soak time. Then they are quenched in either water or glycol. Then you have about 30 minutes to straighten them before they go back in the oven for aging. As you can imagine, the quench can twist a frame into a pretzel. But they are so soft at that point, it is quite easy to straighten if you have an alignment table close by. I only make 7005 frames, so I don't have to worry about solution heat treating 6061 frames after welding. If the frame you are repairing is 6061, re-solution heat treating would be a challenge. Adding reinforcement the way you are is probably your best chance for success on a 6061 frame, unless the stress is being transferred to a thinner wall section of the tube (tubes vary in wall thickness along the length of the tube). If it's a 7005 frame that you are repairing, you could look into re-aging after the repair. I know guys who have done it in a pizza oven.I hope that helps a bit!Mike ZanconatoZanconato Custom Cycles @mzank on Instagram
Reply:Looking good Mike!Looks like Easton in their infinite wisdom pulled down the tech bulletin from their website. Found it England. http://www.sillygrin.co.uk/techstuff...-7005_6061.pdfHope you used 5000 series filler.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Thank you all for your help, advice. I appreciate the document and link to the Fabricator article. I subscribed to it as it seems good reference material. It never occurred to me to look up technical notes on frames and how to weld them. I just kind of jumped into it using prior experience as a repair and maintenance welder. Zank, your input was very encouraging and I will pursue doing more research on the subject so I can have a small reference library of material to draw on. As I put the word out via Facebook on my frame repair service I am getting flack from seasoned riders who basically promote that it is not safe to trust an aluminum bike frame that has been welded. As a result I looked into a local hardening service that does frame hardening for local frame builders. They told me that they charge based on oven fire up cost of $275 plus a charge for the weight of the object to be treated. They have jigs that they use to keep frames straight during the process.For small jobs (like the ones I would take to them ) they put parts to be hardened in the oven with their larger jobs and split the cost accordingly. They couldn't give me a fixed price though and will find out when I take my first piece to them for hardening. My wife is into ceramics as a hobby and she said that people use commercial kilns along the same lines. Small jobs are fit in between larger jobs where there is room, thus taking advantage of the unused areas of the kiln.I'm sorry for not replying sooner. For whatever reason the "instant notification" feature does not always notify. One of the larger and oldest local bike clubs here in Arizona has offered to post an ad for me on their main web page. That should give me some good exposure and maybe move along my plan to get more into this line of work. I am in the process of modifying an aluminum body ambulance and converting it into a mobile advertising display using an embedded large flat screen TV on its driver's side wall. the client wants to use it to advertise his business.While it is not as physical as laying under a truck frame with a torch and sledge hammer cutting out a damaged section and re-plating it, its hard enough for me to pass up in favor of being able to work on the bench with a lab coat on complete with a pocket protector loaded with pens and working on some bike frames. I can't wait!!Thanks again,Tony
Reply:Just make sure you've got proper liability coverage.Mike ZanconatoZanconato Custom Cycles @mzank on Instagram
Reply:Thanks, I'll look into that.Tony |
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发表于 2021-8-31 22:36:45