I wouldn't consider using a MIG (wire welder) for that job. A good person with a TIG (Heli-Arc) welder would be a bunch better. If you don't have any choice but a MIG, I'd preheat both parts to just short of a dull red, use a argon/CO2 mix, a .020 wire and be prepared to grind down the bead. After welding bury the bolt in some dry, clean sand and let it cool down slow. Avoid flux cored wire like the plague! Good luck, Joe.
Posts: 1372 | Location: USA | Registered: 18 June 2000
I agree with jmac. I have also used plain old gas welding to do it. place the work in a box and flood it with co2 gas first. it will inert the work piece and help stop oxygen from ruining the weld.
If stuck with MIG only.......place in a box...flood with the welding gas.....then bevel both pieces to a point. spot weld togather, then grind out the little area left to eliminate any crack. MIG needs room to flow and not just cover up a crack. also use small spot welds in a chain to do the piece. it will come out neater. Keep work piece in the box untill welded. then bury it in sand over night. Works in a pinch. Redd
Thanks for the feedback. I have used gas in the past and it was satisfactory, but currently I only have access to a rosebud and a cutting torch. I was hoping MIG would be a good solution since I have access to a Miller 250. I guess I will take it to town and have the local welder use TIG and the 3% Ni rod. He does good work and is fairly reasonable. Thanks again.
Me tinks youse fellas get a little mixed up in your terminology here: MIG welding is done with an inert gas, like C02. If welding with an active gas, such as Argon mix, we're talking MAG welding. That's what the "I" and "A" stands for, "Inert" or "Active".
I've had no problems using a MAG welder for bolt handles. I have used a TIG welder once and it too worked just fine although, as you know, it is more similar to gas welding and thus isn't for the amateur.
I've mig'd err mag'd a few bolts, and havn't had a problem to date. I used a miller 130 .023" wire and 75/25 gas. The only thing I had troubles with is you have to let it cool a little bit between passes, or the weld will overheat and bubble. I would prefer to TIG it, but don't have one handy, or any local welders I know well enough to trust with the job.
Posts: 7213 | Location: Alaska | Registered: 27 February 2001
I welded bolt handles with Oxy-acetylene for many years. This worked fine but of course the bolt was always heated to the point that rehardening of the cocking cam was necessary. Anyway, a couple of years ago I started using a wirefeed welder and have been happy with the results. I use a mild steel wire and co2/argon gas and it is working out fine. Welds are homogenous and bluing is uniform. I see no reason to preheat when welding on low carbon steel but of course it is necessary on 4140 or medium carbon steel. All in all I,m pleased with the system. Regards, Bill
I've used both MIG and TIG for bolts and while TIG is definately superior, I've gotten fine results with a Miller Mig welder using 0.02 wire and Argon/CO2 mix. Brownells sells some real good nickel steel rod for TIG welding and the results are great. The most important tool you need is a GOOD self darkening mask so that you can clearly See what you are doing and can fill any pits that form quickly. The results are excellent, just take your time. I also use heat stop clay around the bolt to keep it from anealing-Rob
Posts: 6314 | Location: Las Vegas,NV | Registered: 10 January 2001
Argon and helium are inert gases. They do not react with anything during welding. CO2, nitrogen, and hydrogen are active gases. They do react with the metal during welding. The correct terminology for the welding processes are: GTAW - Gas Tungsten Arc Welding commonly referred to as TIG (Tungsten Inert Gas) or Heliarc (which is a Linde trade name), and GMAW - Gas Metal Arc Welding commonly referred to as MIG (Metal Inert Gas) or SIGMA (which also is a Linde trade name).
I've welded them with a Hobart Handler 110v machine with .030 flux core wire and have not seen any problems. Blueing was good couldn't see any color difference. What would be the potential problems' with this set-up?
