MIG just cuz its fast?

[Jawon]

Been wanting to start brazing or welding for ratrod and hobby purposes. Love how fillet brazing looks not to mention lugs but i understand it may not be as efficient as mig.

I was also told by a pro welder that you ideally should not mig thin bike tubes due to distortion. However there seems to be a number of folks who mig their bikes here so i assume there really is no practical issue.

So to the mig welders do you mig just cuz its quicker and easier and you are ratrodding not creating a display piece for the art museum? Have you experienced problems migging bike tubes? If you had the time would you rather go for the brazed results? Thx!

 

[yoothgeye]

I don't braze, mig, or tig, I use a gasless wirefeed welder and my reason is simple... it's cheap.

I know, not the answer you're looking for, but it's an answer.

I don't build show pieces, but what I build is strong for it's intended use.

 

[raggedjim]

This reminds me of the old lead verses bondo conversations.

I mig for a lot of reasons. I have a gas/nogas setup. When my mower or bush hog needs welding I can put some fluxcore wire in and weld in the wind and not worry about the shielding gas being blown away. When I'm inside the garage I can hook-up the gas, reverse the polarity, and instantly get great quality welds (and I am not a great welder, the mig makes it look that way.) If I want to weld sheetmetal (I have welded 20 guage with no problems, I weld in automotive patch panels all the time) I throw some Esab EZGrind .023" wire in and go to town. Bicycle tubes are no problem. This is a scratch built frame I mig'd with no burn through and no distortion. Is it show quality? Not yet but it could be. If I could afford a tig (and knew how to use it) I might be using a tig.

I truly think mig is great for bicycles because it is relativly cheap, easy, and strong. If you are working on lugged bikes then brazing is better. As far as art museums go, I've seen some things in museums I'd be ashamed to display. And I've seen bikes here that deserve to be in museums.

Do what works for you and have fun! I like to learn new things, so I can braze, weld, etch, and JB weld good enuff for me. Good luck, Rg

 

[phusion x]

you are mig welding, your using flux core wire, thats all, still mig welding .

I don't braze, mig, or tig, I use a gasless wirefeed welder and my reason is simple... it's cheap.

I know, not the answer you're looking for, but it's an answer.

I don't build show pieces, but what I build is strong for it's intended use.

 

[phusion x]

yes there is a practical issue, that is the heat index and and arc size for type of fusion welding and material. chromoly tubing crystalizes at 1500 degrees, making it weak around the welds, huffys were mig welded thats why some bikes had not for competition use decals on them. tig welding is lower voltage and has a small arc so it is the olny acceptable method of arc welding that is still uses a arc. brazing is under 1000 degrees and does not dammage tubing. straight guage steel tubing is ok to arc weld on but is not designed for stresses that typical bicycle tubing is designed for. do not use pipe (ie: black pipe) it will break and cause injury it is not steel.

Been wanting to start brazing or welding for ratrod and hobby purposes. Love how fillet brazing looks not to mention lugs but i understand it may not be as efficient as mig.

I was also told by a pro welder that you ideally should not mig thin bike tubes due to distortion. However there seems to be a number of folks who mig their bikes here so i assume there really is no practical issue.

So to the mig welders do you mig just cuz its quicker and easier and you are ratrodding not creating a display piece for the art museum? Have you experienced problems migging bike tubes? If you had the time would you rather go for the brazed results? Thx!

 

[raggedjim]

Chromoly is overkill in most cases for the type bicycles we are building.
My mountain bikes are a different story... I wouldn't ride a bike I built the way I do my Trek...

Rg

 

[backalleyrat]

Oh NO! What do you mean, "switching the ground"? I think this is what I'm doing wrong. With gas, don't I use the ( -- ) negative cable for the ground to the frame? Uh- oh! I think this may be the problem with the lack of penetration on the weld. Any help would be appreciated.

 

[yoothgeye]

you are mig welding, your using flux core wire, thats all, still mig welding .

Actually I was corrected years ago assuming the same thing, MIG stands for "metal inert gas" and I'm not using gas. Mine would be something like metal inert fluxcore wire? MIFW? haha

 

[phusion x]

lol, yes a technicality

 

[raggedjim]

Oh NO! What do you mean, "switching the ground"? I think this is what I'm doing wrong. With gas, don't I use the ( -- ) negative cable for the ground to the frame? Uh- oh! I think this may be the problem with the lack of penetration on the weld. Any help would be appreciated.

Do you have a gas/nogas unit? if so look inside of it (where the wire is). There should be a way to switch the polarity of the ground lead, usually by unscrewing a couple of wingnuts and swapping the leads. Not sure which is which but there should be some instructions inside the machine.

Good luck, Rg