welding

[500rider]

Welding can be a tricky thing.  Even though a weld may look OK it may not be so.  Certain types of weld joints and materials can be susceptable to cracking and have poor fatigue life.  So not only is it a question of proper welding but also weld design, preparation and material selection.  Also, depending on the materials selected there are a variety of filler metals and gases required.  

I am a mechanical engineer and I have also taken a few welding courses (this does not make me an expert).  If you are going to do some welding, you have to assess your skill vs the level of risk.  Welding your own frame is extremely risky (IMO).  I have a flux core MIG welder that I use for some home projects but I wouldn't use it for any stressed members on the bike.  I might use it to make a licence plate holder or something like that.  

We build armored vehicles where I work (lots of welding) and even our weld lab technician, who is a very experienced welder, does not weld the frames for his custom bikes.  He knows that each weld has to be qualified and tested for something where someone's life depends on it.  

For those guys who say they would not spend less than $1000 for a good used welder I guess you have to be realistic about what you will do with it.  If you intend to become a master frame welder than yeah.  But if you use it only once every couple of months then maybe you don't want to spend that much.  I bought mine for $200 used and I think they sell for about $400 new.  

I'm not trying to discourage anyone who wants to get into welding though because I think it is a hell of a lot of fun.  Just beware of welding joints that will undergo high stresses and/or back and forth fluctuations in stress (fatigue).  Anyway, there's my 2 cents.

[Dom]

Well, what part on the bike were you thinking about welding?  Raising or modifying the tail a bit?  No worries...weld a few gussets in there to support the frame pieces and you will increase the strength of the frame exponentially.  And you don't have to worry if they are  unsightly because you can hide them with the tail plastic.  

[GeeP]

I think that you should consider a good Oxy - Acetylene rig.  For  structural steel tube a good torch is the absolute best way.  Using TIG or MIG if the wind is more than 5 MPH is a losing battle anyhow.   :lol:

A Small Victor setup with a cutting torch attachment would probably run about $400 by the time you got set up with bottles.  There are several other good manufacturers out there.  Have a talk with your local dealer.  A good smoke wrench can be a real lifesaver.  

As a side note, there is a guy on the internet who is selling the old Alcoa OFW Aluminum flux:  http://www.tinmantech.com

The only way you are going to learn how to weld is to weld.  You should start with some 1/8" X 4" steel flat.  Practice making butt, lap, and fillet welds in the flat position.  Inspect the finished welds for appearance, slag inclusions, bead height and quality etc.  Then break the coupons apart and check your penetration.  Once you can do a good job on flat position welds, work your way into overhead, vertical up and vertical down welds.

It's also helpful to read a few books on the subject.  Most librarys will have a welding book or two.  Friends who are commercial welders can also be helpful if you can get them to look at your practice work and provide tips.

[quinnbozz]

fweuh,  for a while there i thought this might make it to the "tard farm", not because of topic , but because of debate. :lol:
as long an everyone keeps em above the belt