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Projects Brazing won't last?

Discussion in 'The Hokey Ass Message Board' started by cavman, Oct 17, 2015.

  1. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    I don't like to complain about thread hijacking, but that's exactly what all this chatter about coefficient of friction and etc. is, and to me at least, it needs to go away.
    This thread started as a thread on brazing, could we keep it that way?
     
  2. Well a top fueler has a calculated coefficient of about 4.5.

    So figure out what physics apply to add to the coefficient.
    They always run on glue floor FC and TF -its soooo sticky that on a well prepped track it can pull the shoes off your feet. It's there, so can't ignore it.

    Weight transfer & Wheelie bars change the weight on a tire so that certainly and Empirically effects the Static coefficient of traction and thusly the dynamics of acceleration.


    Special Tire compounds, like you mentioned that do a few things. Grip into the surface and that increases the surface area greatly. That soft compound gets worn down as it rolls leaving much behind in the pavement. Wrinkle walls that again grip bigger, grip harder and change diameter as speed increase, effectively changing the gear ratio and Acceleration.

    So there's a few
     
  3. Get off my lawn !

    Brazing hummm?
    How much more do you want to know.
    Depending on the joint design, You can actually get more out of a brazed joint than you can with welding. But you'd have to pick and choose to the exception.

    Not much furnace brazing will be done in your garage, not much exotic metals in our traditional cars.
     
  4. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    Furnace brazing I know about. The early 4cyl ohc Crosleys had engine blocks built that way, and they did well. Then the bean counters got involved and another cheaper, process was used that was so much of a problem with block coolant leakiage that it destroyed the company's reputation to the point that going to a cast iron block couldn't save them. Sorta like the Vegas with aluminum blocks with an aluminum bore.
    What I would like to learn about, as I said earlier is about the "electric brazing" mentioned a time or two in this thread..
    And BTW, to an old fart like me, the best movie Clint Eastwood ever played in was "Gran Torino".
     
  5. Gotcha. :D

    Aren't you glad you were not my 7th grade metal shop teacher? ;)
     
  6. The first time I saw silicone bronze wire feed welding with an electric source was back in 90 or 91. They were joining copper to steel, a basket ball sized machined chunk of copper to a 40' long tripple wall steel
    pipe. I was amazed.

    It was a Semi automatic set up, crude positioners and quite finiky process.

    When I say "saw" it I mean it was happening in the same vicinity, I never ran the process, but it was pretty cool, especially back then.

    Using electric current doesn't really get brass to flow into and thru a joint. Is more of a line of sight application. Verses flame or furnace heat where the metal flows well into and deep in a joint

    I haven't tried the handheld mig version but I will very soon.

    Running tig and silicone bronze is awesome. There's so many things you can do with it. It's great on cast iron.

    One of my favorite things about is if you're welding 2 pieces together but you want it to look like it was bent or formed instead of welded- join it with silicone bronze. Then run the joint with a flame point die grinder. The bronze is softer and you can slick the bead like a wet finger on caulk.

    It's also great to fill or butter up gouges in steel.
     

  7. The first electric brazing I was involved in was with a carbon torch (a lot like a scarfing attachment only without the air). Ground to the part to be brazed and a carbon rod used on the stinger for heat. We were brazing together of all things a roller coaster in an amusement park.

    We built the coaster in the mid '70s, it passed state inspection and I was by there in then early '90s. The amusement part was more decrepit that a low dollar Carnival but the roller coaster was still standing and in operation.

    That is probably a lot more low tech than we are talking here but it was a way that things got done at one time.

    On the friction coefficient argument there is a theory that a lot of physicists and engineers use to explain it away. I can't pull the equation off the top of my head but it is basically positive displacement. In its simplest form it states that you displace more pavement then your car weighs. Think if it this way, your are spinning your tires yet still moving forward, or displacing pavement. it is kind of abstract but it works if you have the right numbers to crunch.

    Sorry to throw that into the fray, I don't sleep much and read a lot. :oops:

    All that said any good engineer will tell you that real world application and numbers don't always coincide.
     
  8. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 10,264

    theHIGHLANDER
    ALLIANCE MEMBER

    I'm still going to agree with the title of the thread. In it's most common and colloquial sense, that which truly does apply to "our stuff", brazing is a substandard way of fabricating sheet metal. The old customs looked like hell all brazed together until they were wadded up with lead, later with the new flameless miracle known as bondo. over time another process was picked up that would hold the bondo, actual welding with steel to steel. Today we now have MIG and TIG machines in garages nationwide, hell for that matter worldwide. Give me TIG or give me, well, nah fuck it. TIG all the way, but it's kissin cousin MIG can join the party too when the need arises. That blond stepchild, braze, can stand in the corner and wait for that 1 in 10,000 need.

    As for traction coefficients, TF and FC coming into this party, who brought the nitro? I wanna play too:cool:
     
  9. Dooley
    Joined: May 29, 2002
    Posts: 2,969

    Dooley
    Member
    from Buffalo NY

    guys....the thread is not about the best way to join parts it is whether or not brazing will last.

    guess what it does.....now put your dicks away we don't care who thinks they have the biggest or best way to join metal
     
  10. Get off my lawn - you kids get out of here.

    Actually the thread title is what it is and its not" whether or not it will last"

    Threads take a life of their own and that's just the way it works. The question of will it last or not was clearly answered in the first post and according to you and your swinging dick no other comments are needed.
    Careful you don't piss on your boots.
     
  11. Phillips
    Joined: Oct 26, 2010
    Posts: 1,505

    Phillips
    ALLIANCE MEMBER

    I watched my dad braze a few times using a carbon-arc attachment on his Lincoln stick welder. I know he used it after "someone" (seriously it was not me for once) forgot to bring the discharge auger back on a Gleaner combine and bashed it into a power pole coming into the barnyard. Those are all galvanized sheet construction, he did a really nice job straightening and repairing the cracks. Keep in mind this was being done at about 1AM, the machine had to be back in service at sunup. Anytime I tried to braze with that outfit I just ended up with a puddle of brass.
     
    BradinNC and pat59 like this.
  12. Well mines not the biggest but at least I'm circumcised. No pointed peepees in my house. :rolleyes:

    I have discovered in my time that lots of stuff works that can't work. hell bumblebees fly don't they.
     
  13. Back in the day, the railroads used brazing to repair cylinder saddles on steam locomotives.
     
  14. i think brazing and bondo got a lot of bad p.r. by bad execution. lots of stuff works if done correctly. houses built from mud, fighter planes built from wood and glue, cement ships etc......
     
    Dapostman likes this.
  15. Actually getting back to the original post it is cool that it is still holding together. I don't recall if future plans were mentioned but it is way cool to see what we consider too obsolete for our taste still holding together. ;)
     
    Dapostman likes this.
  16. I work in a major automotive manufacturing plant. We still braze all the upper door/window frames to the door outers and up until a few years ago we brazed the roof and quarter panels together. The heat would cave the panels in a little and we would bump the metal out and use a 6" sander to clean it up followed by a DA.
     
  17. V4F
    Joined: Aug 8, 2008
    Posts: 4,382

    V4F
    Member
    from middle ca.

    as stated : brazing is the old way & it was very durable . ask anyone in Europe ! brass was the best in its time . I have used brass in many different applications with good results . I really like using brass ..........
     
  18. the metalsurgeon
    Joined: Apr 19, 2009
    Posts: 1,237

    the metalsurgeon
    Member
    from Denver

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