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Welding Opinion

Discussion in 'The Shop' started by Henry, Jul 21, 2008.

  1. Henry

    Henry Chimp

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    I have an old Gary Fisher Piranha that I have stripped all the paint off and I have taken off the old brake line / shifter cable stays and polished them off to get an even more simplistic look. I also have drilled out the screw things (whatever they're called) that hold the bolts for the bottle holder, etc.

    I went to Gary Fisher's archives and I found out what type of aluminum my bike was made of. (Gold Series 6061 T6 internally and externally butted aluminum)

    If I have a friend with aluminum welding skills and the equipment, do you think it would be safe to try to plug the holes with aluminum and then buff it down?

    I don't want to ruin the frame and I'd like to match the color of the aluminum as close as possible so that the welds plugging the holes aren't noticeable.

    Also, if I'm converting it to a single speed, would welding on new horizontal dropouts be a good idea? My whole "theme" for this bike/project is minimizing the the clutter on the outside of the bike and I don't like the look of the chain tensioner.

    (As for the buffing of the frame, I'm using a large (stationary?) buffing wheel, not a handheld sort (except I will for tight places) so I should get a very uniform polish))

    Thanks all,
    Henry
    (I hope this is the right category to post this in)
     

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  2. CrabJoe StretchPants

    CrabJoe StretchPants Reincarnated Crab Walking Head Spinning Bruce Dick

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    Why you did that is beyond me. Thread 2 screws in the bosses and be done with it. Is it really worth chancing a perfectly good frame for the sake of having a "cleaner" looking bike? Even if you did weld plugs and grind/polish flush, it will still look horrible compared to 2 screw heads.
     
  3. MMike

    MMike A fowl peckerwood.

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    I wouldn't worry about plugging the holes. They are pretty benign.

    The drop-outs on the other hand...not sure that would be a good idea.
     
  4. Henry

    Henry Chimp

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    If I were to not do anything with it, it would end up just collecting dust or getting trashed. The whole reason for this project for me is to just experiment and see what I can do in a budget.

    I don't have to weld plugs in the holes either, I could put in a screw or just plug it with something else. Cork anyone? :P
     
  5. Henry

    Henry Chimp

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    With the drop outs I'll probably leave them alone and just keep the tensioner, but it was just a thought.

    I'll look into it some more.
     
  6. ultraNoob

    ultraNoob Yoshinoya Destroyer

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    Any welding on a heat treated AL frame will require the entire frame to be heat treated again.
     
  7. Stray_cat

    Stray_cat Monkey

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    For filling holes I'd look at using a flux, as opposed to welding in a plug of the same alloy. I'd try and find a low temp flux, that's approprate as an aluminum filler (possibly Flux10 or 14, but the numbers I can never remember as I don't deal with it too much). I'm not sure at what temperature you effect the aluminum comp. which would resulting in needing to heat treat the frame. Ask your friend with the torch.
     
  8. H8R

    H8R Cranky Pants

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    If he knows how top weld ask him if he knows how to braze.

    Fill the holes with brazing and sand smooth.
     
  9. ultraNoob

    ultraNoob Yoshinoya Destroyer

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    excellent Idea!!!!:thumb:
     
  10. Timekiller

    Timekiller Monkey

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    If it was my frame, I'd go for the whole shebang... But then again, I have a TIG welder, and Ive been welding a long time.

    In fact Im building a bike soon from double/triple butted 4130Ch-Molly. Just gotta figure out all the geometry/math first.

    But yes, if he is a good welder, you should end up with a flawless job that you would never know where the braze-ons were. If he is a REALLY good welder, he can work around the heat treating problem.

    Also if you go for it, search framebuilding. When I did, I came across a real trick site that a guy runs his shifter/brake cables through the frame, its neat!
     
  11. Timekiller

    Timekiller Monkey

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    Brazing will not match the finish of the aluminum.
     
  12. H8R

    H8R Cranky Pants

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    Ahh....forgot the "not painted" part.


    Whatever, it's a stupid idea.

    :D
     
  13. ultraNoob

    ultraNoob Yoshinoya Destroyer

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  14. Henry

    Henry Chimp

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    Thanks to everyone for their replies. I'll talk with my friend some more and research this well..
     
  15. yamaguy01

    yamaguy01 Chimp

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    Klein bikes also run their cables inside the frame, I think this looks sweet and makes sense. My cables on my Trek have scratched the heck out of my top tube and all the mud/dirt stays in the scratches. On a white bike it really is an eye sore. Plus it would probably keep alot of debris out of the cable housings.

    Good luck with your project!

    Dave
     
  16. Henry

    Henry Chimp

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    After some consideration, I'm most likely going to either put a rivet in the hole or carve up an aluminum plug on the laithe. I'll most likely go with the latter as rivets don't always look perfect :) (Atleast for me, sometimes I get nice looking ones but other times.. bleh).

    (My friend is an alright welder, but we're both iffy about him doing it so.. maybe next time)

    I know it's not a big project compared to some of the other awesome bikes up here, but I'll have some photos posted later on when I'm 100% finished.

    Thanks for everyone's feedback!