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Post by wheelson on Dec 23, 2020 14:34:06 GMT
Here's a question for those who have delved deep into the bottom bracket areas of the Viscount and the early Lambert frames. First I'll explain an observation:
Earlier this year I acquired a chromed Viscount frame that very nearly matched the Supa (exceptions were no braze-on water bottle mounts and integral rather than separate seat post clamp). When I removed the standard Viscount sealed bottom bracket, I found some material stuffed into each tube junction with the bottom bracket shell: seat tube, down tube, and chain stays. This material appeared to be that green composite dense foam carpet underlayment. I attributed this to the fact that this frame was chromed and this was done to keep the harsh chemicals out of these tubes. Not a bad idea, but I would have guessed they would have been removed before bike was built up in either case. My observation is that all tubes other than the seat tube have no vents and therefore were left sealed. Note the seat tube is open at the top, subject to moisture seepage around the seat post.
The second case is the early Lambert frame I recently received (thanks, Brian!) for Mrs. W. This is the early Lambert with lugs and a standard threaded bottom bracket. When I removed this bottom bracket, I discovered a very tight fitting black rubber plug, effectively sealing all those tubes from the bottom bracket shell. From the looks of things (surface rust), this plug was probably original. If it was, anybody know how long this practice lasted, and did it continue into the Viscount era?
So, in both cases, if this is the engineering philosophy, I would tend to differ as this could lead to some serious tube corrosion problems down the road. To my thinking, any moisture seeping in around the seat post, condensation, or through any vent holes would tend to collect in the thinner tube rather than down in the thicker bottom bracket. Many bikes have a hole or cutout in the bottom bracket to allow this.
My question is this: Was this plugging a common practice, especially on the early Lamberts, and if some of the early Lambert frames suffered from tube breakage around the bottom bracket juncture, might this have contributed to it? Not a critical question, I suppose, but one possible explanation for some of the hits against our beloved bike brand. Enquiring mind(s) want to know!
I'll try to get some photos posted. Brian, did you see anything like this in the frame you recently had with the seat tube crack?
Best, John "wheelson" |
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Post by brianbutler on Dec 23, 2020 17:03:23 GMT
I'm glad you mentioned this. Yes, the Middlebury Pro tubes were stuffed with some type of oiled paper or cloth. I found this out when I heated the bottom bracket for soldering and the rags caught fire with smoke billowing out of the seat tube and head via the down tube. After the fire was put out Some of the material slipped down from the seat tube and I could pull it out. I reached in with a hook and pulled some motre out of the down tube. I believe there is some of this stuff in the rear stays also but I cannot reach it. Initially I thought it might have been left in there after a BB repair but was mystified as to the purpose. It must be from the factory, no doubt a standard practice in the "aerospace" industry and, if so, another reason not to fly.
Brian
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Post by wheelson on Dec 23, 2020 18:47:19 GMT
I'm glad you mentioned this. Yes, the Middlebury Pro tubes were stuffed with some type of oiled paper or cloth. I found this out when I heated the bottom bracket for soldering and the rags caught fire with smoke billowing out of the seat tube and head via the down tube. After the fire was put out Some of the material slipped down from the seat tube and I could pull it out. I reached in with a hook and pulled some motre out of the down tube. I believe there is some of this stuff in the rear stays also but I cannot reach it. Initially I thought it might have been left in there after a BB repair but was mystified as to the purpose. It must be from the factory, no doubt a standard practice in the "aerospace" industry and, if so, another reason not to fly. Brian There used to be oily or chemical impregnated brown paper sheets that served as a wrapping for machine tools or machines parts. Now THAT to me would make good sense IF it wasn’t packed solid. It could lie in the tubes an emit it’s rust preventative without blocking up the tube. Sure would be a lot less messy than Weigle’s or Boeshield. Wonder if that paper is still available? Best, John “wheelson” |
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Post by brianbutler on Dec 23, 2020 21:22:35 GMT
The paper I saw was stuffed in.
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Post by wheelson on Dec 23, 2020 21:47:38 GMT
The stuff I saw back in my previous engineering life was called Cortec and was a paper for wrapping otherwise unprotected newly machined parts. www.theruststore.com/Cortec-VpCI-146-Corrosion-Inhibiting-Paper-Perf-on-Roll-P78.aspx I haven't fully explored this site but it looks like they have a multitude of rust prevention products. I've also been interested in a paint called STEEL-IT. steel-it.com/ It has flecks of stainless steel and looks like it might have some bike applications. I found this stuff years ago in those engineering literature info packs but only recently got around to buying some. Alas, too late in the year to try it out. Best, John "wheelson" |
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