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Paint removal for welding

Old 05-04-23, 05:39 PM
  #76  
LarrySellerz
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Originally Posted by smd4
Except for two days, no time wasted at all.
I work for the government, the taxpayers paid for it haha.
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Old 05-05-23, 12:41 AM
  #77  
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Maybe you should start a new thread before this one gets tedious-

Stycast 2850 removal for welding
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Old 05-09-23, 03:53 PM
  #78  
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Originally Posted by LarrySellerz
I think the repair failed, is better than the zip tie array but the epoxy cracked ...
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Old 05-09-23, 04:22 PM
  #79  
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Steel is Real.

https://portland.craigslist.org/clk/...615838353.html
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Old 05-09-23, 07:04 PM
  #80  
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Originally Posted by LarrySellerz




I found this bicycle abandoned and like the look of the frame. It’s pretty heavy though. This is what I have in mind to put the components of the race bike on.
...that looks like a pretty large frame. I know you feel like size doesn't matter, but in some few categories, it probably does.
The good news is that, from a quick look at it, it has most of what you need to get around as a single speed on it already.

If your wheels from the recently deceased bicycle that started this thread will fit it, you can convert the rear one to single speed, and it has a front brake that will probably work.
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Old 05-09-23, 08:38 PM
  #81  
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Originally Posted by LarrySellerz
Edit: buddy is saying take it to the shop and try to get a warranty from the manufacturer?
Did you purchase the bike or frame new or used?

Virtually all bicycle warranties for the last 20+ years only cover the original owner.

It is possible some of the old Schwinn warranties would have covered the bike under a second or third owner, except the company went bankrupt years ago.
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Old 05-10-23, 10:33 AM
  #82  
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Originally Posted by Eric F
The self-proclaimed Huffy genius, however, seems to be all about the illusion.
If you're talking about who I think you are, he also knows a lot of "science and engineering", too.
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Old 05-10-23, 01:04 PM
  #83  
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Originally Posted by Hondo6
If you're talking about who I think you are, he also knows a lot of "science and engineering", too.
If you ask him, he knows everything about everything, and the rest of us are idiots.
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Old 05-10-23, 03:47 PM
  #84  
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Originally Posted by Eric F
If you ask him, he knows everything about everything, and the rest of us are idiots.
Sounds like youíre confusing Huffy Guy with Schwinn Guy.
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Old 05-10-23, 04:24 PM
  #85  
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Originally Posted by smd4
Sounds like youíre confusing Huffy Guy with Schwinn Guy.
Maybe. I thought those were the same guy.
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Old 05-10-23, 04:26 PM
  #86  
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Originally Posted by CliffordK
Did you purchase the bike or frame new or used?

Virtually all bicycle warranties for the last 20+ years only cover the original owner.

It is possible some of the old Schwinn warranties would have covered the bike under a second or third owner, except the company went bankrupt years ago.
Trek's warranty covers subsequent owners... "Subsequent owners (second or later) are entitled to a 3 year warranty from the date of purchase from the retailer on the Trek frame and Trek fork".
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Old 05-10-23, 06:01 PM
  #87  
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Originally Posted by Eric F
Maybe. I thought those were the same guy.
Yeah, there's some overlap. The Huffy Genius also has a $5 Schwinn and posts mostly in General. The Schwinn Genius was posting in Mech but has threatened/promised to leave. Then there is the Huffy/Campy guy with a legit thread in C&V, not to be confused with the other two.
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Old 05-10-23, 06:16 PM
  #88  
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I don't know how you did this. Was it a fall, or a crash, or a jump? Is the frame still aligned? Can the crack be closed by manipulating the frame?

My fix would be to remove the crank and inspect the bottom bracket. If all was OK and aligned properly I would strip and burnish the area clean then "Alumaweld" a triangular 3mm thick 80mm x 80mm x 80mm aluminum wedge into the area and ride on.
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Old 05-10-23, 06:56 PM
  #89  
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Originally Posted by zandoval
My fix would be to remove the crank and inspect the bottom bracket. If all was OK and aligned properly I would strip and burnish the area clean then "Alumaweld" a triangular 3mm thick 80mm x 80mm x 80mm aluminum wedge into the area and ride on.
I haven't tried that, but I think it is like brazing aluminum, and would be worth trying.

However, I think the bike has had some kind of resin goop put in or around the bad area which only lasted a day, and would make it just that much harder to repair.
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Old 05-10-23, 07:06 PM
  #90  
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Originally Posted by shelbyfv
Yeah, there's some overlap. The Huffy Genius also has a $5 Schwinn and posts mostly in General. The Schwinn Genius was posting in Mech but has threatened/promised to leave. Then there is the Huffy/Campy guy with a legit thread in C&V, not to be confused with the other two.
I guess I missed Schwinn Genius. EDIT: Found it! OMG - lol.

Huffy/Campy guy will never be confused with the other guys. AMCO is in a different league, entirely.
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Last edited by Eric F; 05-11-23 at 10:36 AM.
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Old 05-10-23, 07:40 PM
  #91  
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Originally Posted by zandoval
I don't know how you did this. Was it a fall, or a crash, or a jump?
A light was turning red so I stood up and accelerated to beat the light, and I felt something funny and the bike started making a clicking noise when pedaling. Thought it was coming from the rear wheel at first. I don't know how much any previous crash contributed to it, it had been only ben ridden about 200 miles since the last crash and it had another more serious crash about 400 miles ago. So its seen recent abuse, but it was my fathers old bike and he is also a heavy strong guy who doesn't spin nice circles so the bike also experienced a lot of normal fatigue through the years.

my buddy from Bosnia says I should drill some holes to mount a bracket to fix it, similar to your idea. I think Ill never trust the frame again even if I fix it, bike is dead, but the parts on it are newish and fancy. Worth salvaging. Its semi-abandoned with a sign on it saying the frame is busted and not to ride it, I think im going to store it somewhere hidden away at work ("radiation tunnels" for a discontinued part of the accelerator) but I dont want someone finding it and hurting themselves on it in the future.
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Old 05-10-23, 07:44 PM
  #92  
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Originally Posted by Eric F
I guess I missed Schwinn Genius.

Huffy/Campy guy will never be confused with the other guys. AMCO is in a different league, entirely.
Exactly. Though even I forgot about $5 Schwinn Guy.
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Old 05-10-23, 08:00 PM
  #93  
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Originally Posted by LarrySellerz
Luckily, my partner at work is a master welder.
Any person who is a master welder will refuse to even try to weld this. And any person that agrees to weld this is not a master welder.

Originally Posted by LarrySellerz
Ive read that the seat tube is the least critical of the tubes in the bike,
And yet... it broke. There was enough stress to break the factory welded frame, which had the benefit of a post-weld heat treat. A repair weld will be weaker than the factory weld. What makes you think that its possible that the respair will hold?

Originally Posted by LarrySellerz
but now that its gone what tube/joint is experiencing the most stress? Thats my biggest concern honestly, the bike flexes and eats up my power now but its not terrible,
It's not terrible? Based upon what? A stress analysis evaluating vector forces on the frame? Your gut feel?

Originally Posted by LarrySellerz
dont think it will crash like this.
Physics, and the strength of materials really, really, really doesn't care what you think. You can be happily riding on your flex-o-matic one second and paralyzed the next, from your head hitting pavement and breaking your neck.

Originally Posted by LarrySellerz
Edit: buddy is saying take it to the shop and try to get a warranty from the manufacturer?
Ah, so maybe he/she does have some competence. If warranted, transfer parts to a new warranty frame. If not warranted, buy a replacement frame and do the same thing.

I mean... I only have PhD in Engineering and am a registered professional engineer, so perhaps you gut feel is a better guide than the education, 40 years of professional experience, including 5 working in a bike shop.

I mean what was it that Matt Damon said about crypto? "Fortune favors the brave"!? Oh.. wait..
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Old 05-10-23, 08:26 PM
  #94  
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Originally Posted by WizardOfBoz
Any person who is a master welder will refuse to even try to weld this. And any person that agrees to weld this is not a master welder.


And yet... it broke. There was enough stress to break the factory welded frame, which had the benefit of a post-weld heat treat. A repair weld will be weaker than the factory weld. What makes you think that its possible that the respair will hold?


It's not terrible? Based upon what? A stress analysis evaluating vector forces on the frame? Your gut feel?


Physics, and the strength of materials really, really, really doesn't care what you think. You can be happily riding on your flex-o-matic one second and paralyzed the next, from your head hitting pavement and breaking your neck.


Ah, so maybe he/she does have some competence. If warranted, transfer parts to a new warranty frame. If not warranted, buy a replacement frame and do the same thing.

I mean... I only have PhD in Engineering and am a registered professional engineer, so perhaps you gut feel is a better guide than the education, 40 years of professional experience, including 5 working in a bike shop.

I mean what was it that Matt Damon said about crypto? "Fortune favors the brave"!? Oh.. wait..
Engineering question for you, what is the next joint to fail? From what I understand the triangle is now a parallelogram, and it will fail near the forks, but which joint do you think it would be? I live on a 20% grade hill and Ive been told it will fail when I use the front brake
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Old 05-10-23, 08:33 PM
  #95  
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Originally Posted by LarrySellerz
Engineering question for you, what is the next joint to fail?
Simple question for you, does it matter?
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Old 05-11-23, 10:22 AM
  #96  
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Kind of agree with smd4. If you are in an airplane, knowing that the left wing will fall off first is not operationally actionable. The seat tube is an integral part of a system (the diamond frame) and removing it adds stress to both joints (down and top tube) to the head tube. It also adds bending moment at the rear dropout. At any of these joints the failure mode can be catastrophic (as in your face being scraped away on the pavement).

It's an al frame, and welding it would be difficult (difficult geometry, "hot shortness" which is al welds are very brittle when hot and often crack, and a signficiant heat-affected zone size leading to premature failure). It's dead, man. Let that frame rest in peace.
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Old 05-11-23, 10:49 AM
  #97  
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Originally Posted by WizardOfBoz
It's dead, man. Let that frame rest in peace.
Amen! But I think you really mean let it rest in pieces.
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Old 05-11-23, 10:56 AM
  #98  
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i was thinking of quitting BF because it had become so repetitive, but then this thread showed how even within repetition, new heights can be reached. faith in universe momentarily increased. what a gem.
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Old 05-11-23, 11:16 AM
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"Abandoned"---?
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Old 05-11-23, 12:15 PM
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Originally Posted by LarrySellerz
Engineering question for you, what is the next joint to fail?,,
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