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Thread: Frame building.

  1. #1
    Clyde Racer. .Cole's Avatar
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    Frame building.

    I am looking to build my own fixie frame and have it completely drawn up a ready to rip. But one problem.

    I have no idea on how to weld. I know alot about geometry and designs but have come up short in the welding department.

    So my design is ( I hope) going to be perfect for my particular body. I have it drawn up on paper and in CAD.

    The hard part is welding, I have been wrenching for almost 7 years now. I need to know what kind of welding is the best for frame design. People throw all the acronyms around and I sure as hell don't know what they mean.

    I would just like some basic info on frame building. The actual building, designing is the easier part for me.


    I also would like to completely avoid lugging. The frame.
    Currently logging 900 miles per month. =0
    Quote Originally Posted by I-Like-To-Bike View Post
    In some scenarios women might enjoy a few extra inches.

  2. #2
    Extra Medium Member redtires's Avatar
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    Well...
    For lugless, you can go two ways, either TIG (Tungsten Inert Gas) welding or fillet (brass bead) brazing. Since you've never done it before...my first reaction is to say go with a fillet braze. It tends to have the least amount of investment in equipment and it's a bit harder to make an irreversible mistake. TIG welding requires that you have, well a TIG welder for starters, and a good used one will run you around $1500 for starters. Then you would need a tank of Argon gas, gloves, face shield, welding wire. Also, you would need quite a bit of practice playing with the amperage level that is right for your tubings wall thickness, not to mention a bit of practice with technique.

    Fillet brazing on the other hand is not as much of a chore to learn and get good at, and you have more room for error and fixing a screw up. Equipment can be had for pretty cheap, all you'll really need to buy is an oxy-acetyline torch with a size zero or "1" tip, about 20 feet of hose and a regulator for each of the tanks. The nice thing is that I can't tell you how many times I've seen oxy-acetyline set-ups in a pawn shop for cheap, you just need to look around. The gas cylinders can be rented, and you would not need to get enormous sizes. Other peripheral materials would be brass-bronze brazing rods (I preferred to use 1/16" rods when I built, but some builders prefer 1/8"), brass flux, applicator brushes, brazing goggles and a good dremel to finish your brass beads. Brass brazing is also easier to learn in my opinion and makes for a very strong frame. Brass tends to have excellent torsional strength and is very suitable for brazing frames. Plus, if you really screw a joint, you can almost always pull the tubes apart, clean them up and start over. Although, I don't recommend this officially, heating and cooling will change the structual properties of the steel, making it more "brittle".

    There are tons of books and reference material available for either one of these techniques, so do some research and make sure that with whichever method you choose, put some practice in on some scraps to see how your technique works.

  3. #3
    Clyde Racer. .Cole's Avatar
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    I am going to go with Fillet Brazing. Do you think I could get the setup for under 200? I will definetly go Pawn shop hunting over the next few days.

    I already have a dremel so that will be a plus.
    Currently logging 900 miles per month. =0
    Quote Originally Posted by I-Like-To-Bike View Post
    In some scenarios women might enjoy a few extra inches.

  4. #4
    Clyde Racer. .Cole's Avatar
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    Would something like this be appropriate?
    http://www.lowes.com/lowes/lkn?actio...659&lpage=none
    Currently logging 900 miles per month. =0
    Quote Originally Posted by I-Like-To-Bike View Post
    In some scenarios women might enjoy a few extra inches.

  5. #5
    Extra Medium Member redtires's Avatar
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    Quote Originally Posted by .Cole View Post
    Would something like this be appropriate?
    http://www.lowes.com/lowes/lkn?actio...659&lpage=none
    Yes, that is exactly what you need. Just don't use that huge oxy tip or you'll blow a hole straight through the tubing!!

  6. #6
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    Quote Originally Posted by redtires View Post
    Well...
    Fillet brazing on the other hand is not as much of a chore to learn and get good at

    No that's incorrect.

    Fillet braze welding (not brazing) requires a finesse and an understanding of welding more than you will be able to teach yourself.

    I have seen plenty of framebuilders flow braze in wavy lumps and call it fillet welding but it isn't, most get away with it by flowing in about 5 times more weld metal than required and linishing it back into 10-12mm fillets which defeats the purpose of going lugless to reduce weight.

    Find a reputable school or course and learn to weld properly, Trade skills aren't learnt overnight.

    BTW I've always found the Lincoln product (link) to be very good.

  7. #7
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    Fillet brazing isn't intended to be light

    "Going lugless" isn't typically done for weight savings, and the poster who suggested fillet over TIG is correct - fillet is easier to learn to do at a basic level (note that I'm not saying that *mastering* the skill is any easier), cheaper, and far more forgiving of mistakes. I've helped friends learn to safely join tubes with fillet on the O/A setup in a single afternoon. That's not saying that they're ready to run out and braze up an S3 tubeset, but with basic, thick cromoly tubes, and some patience and care, a beginner can do a safe (if not all that pretty) job of building a bike.

    Get an O/A setup, get a bunch of scrap tubing, and braze up some fillets. Then try to break things, cut up the joints to look at where the brass went and where it didn't, etc. When you think you're ready, build a bike. Forget TIG unless you want to become a professional builder - it costs a ton, it's hard to learn, and the only advantage, really, is speed, which isn't a concern if you just want to build one or two bikes.

    -Walt

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