I'm on here out of interest/learning (no knowledge or experience of MIG brazing whatso ever), but it strikes me that if you've found some wire that's extremely cheap it could be a really bad gamble. With many things cheap consumables are cheap for a good reason, they can be rubbish. When learning a new skill the last thing I'd want is to risk starting with something that may not be up to the job. If you know what you're doing you can sometimes cope with substandard stuff, but as a learner it might end up causing you to get poor results, get frustrated and ditch the process as being rubbish when it could actually be faulty wire. Personally I'd be spending extra on something that I knew would be good, and give myself a fighting chance.
I have done a fair bit of mig brazing with various machines and purchased a few rolls of wire new, I’ve also watched eBay auctions for the stuff and seen a lot of it badly or incorrectly advertised. Put a link up to the wire you are looking at buying and I’ll cast my eye over it. It’s a great process but only on clean steel
I believe mig brazing wire was developed for vehicle body work [modern steel contains Boron] so cannot be welded with conventional ER70S..
finally got a chance to try it out today, first mistake was I hadn't ordered a 1.0mm tip but I got by with the very worn tip off my old welder I set the machine to Cusi (gas is set to argon automaticaly) and set the metal thickness first pass was ok, but a little messy, so I turned the fillet setting (?) back down to zero and tried again and it was much better this is an overlap joint, I ground it down to see if the weld was continious, then tried bending it to check strength and was pleased to see the steel gave way before the weld. I also cut through it to check flow and penetration Suitably impressed both with my cheap ebay wire and my new found skills (!!!) and feeling brave I dug out the tank I needed to repair. There was two problems, a pin hole near the outlet and a previous repair with what looked like solder. I cleaned up the area and made a patch, welded it on, then ground it down to check for pinholes what looks like a pinhole in the last pic is just a slight crater and fine.
the second repair was made to the area where the steering column paases through the tank (tractor!) my technique improved by the last bit and I think I hadn't cleaned the top enough very happy with the results and this was a good choice od process for this repair. There is still a slight leak, but that down to missing another pinhole and an area where the seam is weeping on the second repair.
Good to see the results of one of my favorite wires in a machine I have yet had no experience with. That's a minarc-mig evo 200?
yes, it is. I need to play with it a bit more to get tidier joins but I've got another project in mind for that. I was impressed with it though and the machine makes life so much easier
In a word, fantastic, been putting together the chassis for my Beach Buggy over the past few weeks. Mostly 3-5mm box and plate and it has performed far better than my talents show
Its not tidy in fairness but Brazing through a mig doesn’t wet well at all. It’s tricky to make an attractive job of it. The dip transfer along with pure inert shield and zero dilution all contribute to a cold looking peaky welds. (Runs sorry. It’s not a weld) However it’s very useful at what it does.
It wasn't said as a criticism (I can't even do the process at all), my thoughts were more that it appears uneven in the sense of an unsteady hand rather than poorly done, if that makes sense.
More shakey than unsteady It is a tricky process, made worse by the weld pool not being molten as such so you I was trying various ways to move the weld pool along. I'll be re-visiting this process as I can see a lot of uses for it for non structural car bodywork. I also have a fuel tank to build from scratch which this would be ideal for, but for that I would rather not dress the welds at all if possible so I will need to practice more first
I have read that Biodiesel can corrode Copper at a higher rate than it does Mild Steel. I dont know anything about it bar what I read but it maybe worth knowing.
Googled it and found this........http://biodiesel.org/docs/ffs-performace_usage/materials-compatibility.pdf?sfvrsn=4 Im not sure if its relevant
