Asking if any of you have tried mig brazing? The wire is kind of expensive and requires pure Argon instead of my usual 25/75 mix. But, I have some rust patches to do and the low heat should keep warping to a minimum and much easier to grind than steel. Anyway, any experience and if so did you use the argon recomended or try it with mix?
Body men used to braze a lot of panels. However, guys now remove any brazed panels they find and weld in new; just saying.
I just got done trying MIG brazing.I was going to do the lower half skin on a 55 Chevy door,and figured this might be the way to go on a 46 inch skin.I have gas brazed many times ,and liked the way br*** flows. MIG braze doesnt flow like gas brazing.It puts down a tall bead.I practiced on some s****,and tried turning up the heat, down the heat,more gas.Just didnt find what I was hoping for. I TIG so the Argon will get used anyway. I ended up MIG welding very slowly. I found that grinding down welds puts more heat in the steel than the weld. Dont try running a grinding disc over a long weld. I ended up using a grinding wheel in a dremel,. Do a couple spot welds then take them down with a small dremel.Much less heat build up.
The use of mig brazing has increased a lot. Many manufactures recommend that non factory joints (sectioning) be mig brazed. Its different from steel wire. I haven’t used it to “braze” a rust hole. I use TIG for that on occasion. So much easier to drop the molten filler rod in the hole rather than the sudden heat from the mig process. If you use the bronze, practice on the same thickness metal. It’s a good bit different.
I've wanted to try it and heard that with practice it works pretty well. Just haven't put out the initial cash to try it, too many other things to spend that money on.
Years back on a different site there was a guy repairing a broke up old cast iron lathe with bronze mig welding. As I recall it worked pretty good.
Bronze brazing supposedly had paint adhesion issues and is brittle, Ive never used it for bodywork. Learned how to do it years ago and have had to braze on a few occasions since. Any of these issues with mig brazing ? Whats the advantage of bronze mig vs steel mig? Is the joint more malleable- easier to hammer, easier to grind? Is the heat lower for less warpage ? Im genuinely interested, need to understand the advantage over steel wire.
The OEs recommend its use because of less heat and corrosion resistance. It’s used in sectioning (non -factory seams) Tests claim it’s more than strong enough for a **** joint. The paint issue with the old method was more to do with the flux. This is eliminated now with the shielding gas.
I ***ume you are talking about silicon bronze MIG wire. Yes, expensive. The OEM's use it as filler on spot-welded joints like where the quarter panel meets the roof. In this case the strength is the spot weld, not the MIG braze.
I have brazed lots of stuff over the years, but I'll be damned if I could ever get good paint adhesion on it.
I’ve also done torch brazing and the only paint adhesion problems were due to not. Cleaning the flux well. Finally found the key, lots of hot water and brush scrubbing. I liked the low warpage with the torch braze and am hoping someone can vouch for the mug process. Really hoping that gas mug would work. There's no flux in the mug process so that shouldn’t be an issue.
MIG "braising" has been used for many years. It's Silicon Bronze wire that has a melting point of 840 degrees so it melts at a lower temperature and causes less distortion. Yes, the process uses 100% Argon shielding gas and the silicon bronze weld will take paint well. Many people hear the word "silicon" and ***ume that paint won't stick to it, not so.
I know some don’t like it but know of no reason to remove. It’s present on several cars from the factory in certain locations.
a quick overview of why it’s used today. The silicon bronze is used to attach high strength steel. It’s also used to join parts such as rockers and quarters in the section location (non factory seam). Those are **** welds with silicon bronze only. Makes a nice clean joint. But these shop are using some nice high tech mig welders for this.
Good stuff, Im learning. shielding gas eliminates need for flux, so the old concern of paint adhesion with torch brazing is eliminated. Lower heat, less distortion
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