tag:blogger.com,1999:blog-6467858377106451384.post2835921179854793519..comments2024-03-29T10:52:55.716-04:00Comments on Lovely Bicycle!: Welding and Brazing: a VisualVelouriahttp://www.blogger.com/profile/00359329171411037482noreply@blogger.comBlogger31125tag:blogger.com,1999:blog-6467858377106451384.post-19821028166275738492013-04-17T18:04:50.788-04:002013-04-17T18:04:50.788-04:00During welding steel we have about 1300 Degrees of...During welding steel we have about 1300 Degrees of Celsius. Around weld creates structure called "thick grain" (in microscopic scale). Area around weld is in fact weaker than the weld itself. To balance this welded parts should be normalized in a oven. Steel is being normalized around 800 degrees of Celsius. During brazing temperature is about 900 Degrees of Celsius and during brazing there isn't created structure called "thick grain" (in microscopic scale). Brazed details thus don't need to be normalized. But technically speaking weld (+ normalizing) is mechanically stronger than brazing. Not every welding facility takes care of normalizing steel frames after welding.Maciej Dlugoszhttps://www.blogger.com/profile/15524749535193219789noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-53848973437879709452012-02-14T16:45:00.652-05:002012-02-14T16:45:00.652-05:00I think that the owner of this particular frame sh...I think that the owner of this particular frame should consider getting it clear-powdercoated. The more I look at my pictures, the more I think the rainbow pools and coppery outlines would look great "in the nude."Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-62219444397631650972012-02-13T16:23:35.806-05:002012-02-13T16:23:35.806-05:00I like it as well. A raw or clear-coated welded fr...I like it as well. A raw or clear-coated welded frame could look really nice.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-16941991737677590282012-02-13T16:02:51.596-05:002012-02-13T16:02:51.596-05:00It's true that these opportunities don't p...It's true that these opportunities don't present themselves often, unless you find yourself in a frame shop that produces frames with both TIGged and fillet brazed junctures. I found these 2 close-up pics of unpainted BB shells, one TIGged into a frame, the <br />other brazed. (I'm currently a student intern in a special education classroom, and it's helping me figure out methods to use photos to clearly illustrate concepts. Now, if only I could *take* a decent photo.)<br /><br />hth<br />-rob<br /><br /><br />http://www.kirkframeworks.com/images/bb_for_index.jpg<br /><br />http://t3.gstatic.com/images?q=tbn:ANd9GcTRvLN9dEULegn9TKX-7HzlTJ1ZqUOb3L0jHTS9f_Rnjn1ZW0BF1pTF_7ThScreechhttps://www.blogger.com/profile/15397676711365438175noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-80050818559112428202012-02-13T13:44:04.990-05:002012-02-13T13:44:04.990-05:00There used to be a disadvantage to welding bicycle...There used to be a disadvantage to welding bicycle tubes and now it's not an issue if tubes designed for welding are used.<br /><br />Lugs still function quite well as stress distribution collars as RR puts it. For frames that will be used and abused for many years lugs still have some theoretical advantages. Realizing those advantages requires a lot of labor and a certain amount of weight.<br /><br />Making a frame weld work requires tight mitering. It's an absolute precondition. A bad miter will be difficult to weld and will usually show. Lugged frames should oughta be mitered just as precisely but you never really know. The welded frame also can be mitered and built to any angle while the lugged frame has to conform to the angles built into the lug, or the builder has to do significant work and/or make significant compromises to adjust the lug.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-40167043570856990902012-02-13T13:30:31.133-05:002012-02-13T13:30:31.133-05:00You're correct that welding bonds one tube dir...You're correct that welding bonds one tube directly to another tube and brazing bonds two tubes together via either a lug or a fillet so that the two tubes are actually bonded to either the lug or the filet rather than directlt to each other. I think it bears clarifying (and I'm only about 97% certain of this) that a lug is an external sleeve that the tubes to be joined slide into whereas a filet slips inside the two tubes to be joined. Nicely carved lugs can add visual appeal to frame (like all of those frames at Rivendell) but a properly done filet joint is a seemless joint that's pretty much invisible.mattnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-56146213432149254332012-02-13T13:22:10.702-05:002012-02-13T13:22:10.702-05:00I just really like the look of the welding pool I ...I just really like the look of the welding pool I guess. Kinda like the oil-sheen on a puddle of water. A little strange, I know, maybe it's my way of celebrating not being color-blind. I've been told I'm tone-def so I try not to sing too loud.Johnhttps://www.blogger.com/profile/13313339952032622637noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-82460019679907832282012-02-13T13:12:22.232-05:002012-02-13T13:12:22.232-05:00I think this comparison should be thoroughly teste...I think this comparison should be thoroughly tested.Johnhttps://www.blogger.com/profile/13313339952032622637noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-19440149648683360282012-02-13T09:09:41.037-05:002012-02-13T09:09:41.037-05:00Anna - As Richard Risemberg suggests below, in the...Anna - As Richard Risemberg suggests below, in the past, higher end tubing was not necessarily designed to withstand welding. The cheaper bikes of the era used tubing thick enough it could probably withstand a nuclear blast.<br /><br />Changes in tube manufacturing and better TIG welders today have for the most part eliminated all but aesthetic differences in bicycle tube joining.<br /><br />My two bikes are lugged steel. Well done fillet brazing make the best looking bike in my opinion. Only a few have the skill necessary though.Matthew Jhttps://www.blogger.com/profile/10408057524387021992noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-63783029342003042812012-02-13T00:48:25.750-05:002012-02-13T00:48:25.750-05:00Just so I understand this, are you saying there is...Just so I understand this, are you saying there is an advantage to welding those particular tubing models as opposed to brazing them? or only that there is no disadvantage to welding them?Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-13018508254217685572012-02-13T00:45:18.990-05:002012-02-13T00:45:18.990-05:00Is there anything in the way of statistics compari...Is there anything in the way of statistics comparing actual failure rates for lugged, fillet brazed and welded frames? I have seen loads of broken lugged frames in my day, but not many broken welded frames.Annanoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-27742274679643375792012-02-13T00:39:46.647-05:002012-02-13T00:39:46.647-05:00I was wondering that myself. I assumed it was a Pa...I was wondering that myself. I assumed it was a Pacenti initially, but it does not seem to resemble any of their models.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-47409272095922227652012-02-13T00:39:29.823-05:002012-02-13T00:39:29.823-05:00It is surprisingly difficult to find pictures I...It is surprisingly difficult to find pictures I've taken that are comparable side-by-side. Ideally I would love to photograph 2 unpainted frames representing each method next to each other, but that kind of opportunity has not presented itself yet.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-30858481069040482812012-02-13T00:33:32.666-05:002012-02-13T00:33:32.666-05:00The fork crown in the flickr set is gorgeous! Is i...The fork crown in the flickr set is gorgeous! Is it a Pacenti or did the framebuilder make it?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-92174289482779850902012-02-12T20:38:06.599-05:002012-02-12T20:38:06.599-05:00Veloria,
I think the pictures of the Wojcik frame ...Veloria,<br />I think the pictures of the Wojcik frame illustrate the visual differences between welds and braze-ons. I also think your explanation was good; surely a simplified explanation, but that was the intention, wasn't it?<br /><br />I think it might also be helpful to show some pics of a frame where the main tubes have been joined by fillet brazing next to a frame where the main tubes were TIG-welded together. Of course, your readers can easily images.google that themselves, to compare the smooth and seamless fillet brazing to the stack-of-dimes (on good examples) of a TIG weld...<br />-robScreechhttps://www.blogger.com/profile/15397676711365438175noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-1748049564795544662012-02-12T20:32:59.059-05:002012-02-12T20:32:59.059-05:00Basically, it's the air-hardening steel alloys...Basically, it's the air-hardening steel alloys that are said to actually benefit from welds. In the Reynolds range, these are the 853 (heat-treated) and 631 (cold-worked.) The current 725 stuff is heat-treated chromoly; the classic 753 was heat-treated manganese-molybdenum steel. These can be safely welded, but they don't share the air-hardening benefits of the 631 and 853.<br />-robScreechhttps://www.blogger.com/profile/15397676711365438175noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-20555432741181656272012-02-12T19:53:38.151-05:002012-02-12T19:53:38.151-05:00Many of the newer steels (ie Reynolds 7xx and 8xx ...Many of the newer steels (ie Reynolds 7xx and 8xx series) are specifically designed to be welded without becoming brittle. They can also be very strong at lower wall thicknesses, thus giving a light yet sturdy frame.<br /><br />They can, of course, be brazed as well, with or without lugs. Lugs do add a bit of strength--I have seen them referred to in technical literature as "stress distribution collars"--but welds are strong too, and the techniques of welding are widespread and well-developed.<br /><br />An acquaintance of mine who has a very high end machine shop says that his welder can weld two soda pop cans together without harming the metal, and has done so to show off.<br /><br />For very light tubing, such as bike frames, I prefer lugs, but I have one of each right now. However, the lugged bike is 45 years old, I have put over 30,000 miles on it myself on rough LA roads (who knows many miles it covered before me), and it is a very light ex race bike, so I'm pretty comfortable with lugged frames! (In fact, it has fenders, rack, & lamps, and is STILL light!)Richard Risemberghttp://www.bicyclefixation.comnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-33225400550004246242012-02-12T19:12:28.430-05:002012-02-12T19:12:28.430-05:00Um... What debate? a "vodka martini" is ...Um... What debate? a "vodka martini" is not a martini!!Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-37381480591254513682012-02-12T19:06:23.465-05:002012-02-12T19:06:23.465-05:00The welding vs brazing debate is like the gin vs v...The welding vs brazing debate is like the gin vs vodka martini debate: all a matter of taste!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-81962169213997406842012-02-12T19:06:17.265-05:002012-02-12T19:06:17.265-05:00Thank you Leo for your informative post.Thank you Leo for your informative post.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-5500158072962667872012-02-12T18:41:35.716-05:002012-02-12T18:41:35.716-05:00I think it will be set up with a 3-speed drum brak...I think it will be set up with a 3-speed drum brake hub.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-78479601914312626872012-02-12T18:36:57.392-05:002012-02-12T18:36:57.392-05:00interesting frame! is it a single speed?interesting frame! is it a single speed?nancy dancynoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-59738037626947006402012-02-12T17:29:43.262-05:002012-02-12T17:29:43.262-05:00I think people are missing an essential point. In ...I think people are missing an essential point. In a weld, the metal is raised to a high enough temperature to actually MELT it. More melted metal is added to the joint. The welding process does not "glue" the pieces together, but melts them together and in effect makes them one piece of metal. <br /><br />The heat to do this can come from an electric arc or a gas flame, usually acetylene.The high heat will modify the properties of some metals, but not stainless steel or aluminium. Alloy steels should be welded with a filler rod that matches the metal being welded. High carbon steels will lose most or all of its "springiness" by being melted.<br /><br />Brazing is more or less like glueing two pieces of wood together with liquid glue, except the "glue" is another metal that has a lower melting point than the metal being brazed. There is no melting of the metal being brazed.<br /><br />This is a bottomless subject. Google it if you are really curious. I put in seven years as a welder in industry at one point in my life. With the proper equipment and technique, one can weld a metal and change the charactoristics of it to a very minimal extent. My area was high pressure pipes.<br /><br />Leo<br /><br />LeoAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-16019654718950158602012-02-12T16:30:20.286-05:002012-02-12T16:30:20.286-05:00It does look like the frame should be cleaned befo...It does look like the frame should be cleaned before going to powdercoat.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.comtag:blogger.com,1999:blog-6467858377106451384.post-58748954455942765972012-02-12T15:32:28.970-05:002012-02-12T15:32:28.970-05:00Yes there is a filler material in the weld pool. I...Yes there is a filler material in the weld pool. I did not want to complicate things by mentioning that.Velouriahttps://www.blogger.com/profile/00359329171411037482noreply@blogger.com