Vintage Mustang Forums banner

Welding Woes, trust but verify

1K views 8 replies 7 participants last post by  MikeG69 
#1 ·
Hey all,

I figured I would take this time to share my experience with Mig welding and an extremely frustrating situation that I put myself into in hopes that some new and old restorers can benefit from either my experience gained or some kind of laughter.

Background, I am no stranger to Mig welding. I have done it for the past 15 years with shop machines at places I have worked or with a friends machine. I always loved Mig welding as it was easy to do and once you got the machine set right for the metal working on, it was a piece of cake, especially with exhaust work. However, I never really took the time to learn how it all works, what else can the machine(s) do, or different kinds of wire. A little over a year ago my father surprised me with my own machine, a Lincoln 140HD 110v for home use. What a great gift! I got the machine home, put together a cart for it, got a bottle of mix, and put the beautiful red machine on the car. I opened the side door and took a look at the internals. I looked at the electrical wires coming off where the gun connects to the machine (I know the nomenclature now, back then I didn't) and noticed that it was already wired to the machine. So, without reading the instructions, I ran the ground clamp cable through the front of the machine and connected it to the other threaded post. I ran some .025 Mig wire through the machine, turned on the bottle, grabbed some scrap 20 gauge and gave her a shot. It welded and I was happy for that. So, since then I have done a lot of thin metal work on my car. But as time went on I started to notice that plug welds took a long time to fill (got penetration but it took a lot of wire and time), welding upside down was almost impossible, and that on the thick metal (10 gauge to 3/16") I would have to turn the machine all the way up (heat and wire speed, way higher than what the door recommended) in order to get that nice bacon sound but the weld was HUGE and didn't penetrate like it should. This was ONLY on the thick metal, thin stuff it did fine with. The door said the machine could weld this size metal prior to switching over to Fluxcore. Now, keep in mind I didn't know much about Fluxcore as I have never used it but I did know it didn't need gas. I had a spool of it so I decided to give it a shot. I ran the wire through the machine and changed the tip and struck an arc. It was NICE with very little spatter. So, I figured for the thick stuff I would need to use Fluxcore. I also sent Lincoln an email asking them why my machine was so far off form the door recommendation and the response was "those are just recommendations to get you started, if it sounds right then where you have the machine set is fine."

I was still very bothered that Lincoln would put out a machine that couldn't do what they claimed to could and was ready to call and complain and demand warranty! So, yesterday while I was getting ready to weld my subframe connectors on the car, I decided to test the machine prior to welding. I could NOT get what I needed from Mig. The welds looked like crap on the thicker stuff, all thick and thin with no penetration. At this time I had read online that I should switch the polarity inside the machine for Fluxcore. So, I did just that when I changed back over to Fluxcore to test prior to welding the subframe connectors. IT WELDED LIKE GARBAGE!!! For a split second I thought my machine was trashed because everything I did went downhill. But then a light kicked on in my head. Could it be that the welder was already set to DCEN when I got it and that's why the original test with Fluxcore went so well? BOOM, there it is. To verify I OPENED THE INSTRUCTIONS which had collected an 1/8" of dust since I tossed them into the corner and confirmed how to set the machine up for Mig and Fluxcore. I had it backwards the ENTIRE time. So, I left the machine in DCEP and ran some .030 wire through it, turned on the gas, and WOW. This thing welds so nicely. It was like Christmas in March for me I was so happy. I immediately went and tacked on the subframe connector to the car, did some plug welding, and finished the rest of the connector with a multi pass. Night and day difference.

So, what did I learn? In the Air Force we are taught to trust but verify, I failed to do this as I thought it was logical since Lincoln had the electrode already connected to the negative terminal that I should just connect the ground clamp to the positive which was wrong for my application. Reading the instructions for setup would probably (I'm a man and I don't need directions!!) have been smart. Lastly, these 110v machines are great for at home work!!!

I am somewhat worried about my previous welds (new frame rails, torque boxes, radiator support, aprons, upper/lower cowling, firewall, floor supports, and floor pans), however I did check every weld for penetration and it always got bright red on the other side of the material and looked like good penetration. I had to turn the machine way up to get what I needed for the thin stuff and I had to use a lot of wire to get what I needed. I am going to go back through and add some welds in all the areas listed above to ensure structural integrity. I still don't know if physically the welds are strong or not and I am worried about this and if I have to drill out all the welds and start over I will. That's what I get for not reading the instructions.

I am a bonehead!!!
 
See less See more
#2 ·
Hmmm...

Interesting. I have an older version of that same welder and really like it. A few times I needed more power...but if something is critical I've got access to larger welders at work.

If I'm reading you right...the setting you were using (reversing polarity) is what they recommend for aluminum welding (along with different gas)?

I've got that on my big list of things to try someday...but haven't gotten any further than buying some wire and a tank of gas.

Phil
 
#3 ·
LOL! I have basically the same machine....luckily, I had read a post very similar to yours so when I switched from flux core to MIG, I had a heads up that I probably should read the directions and switch the terminals around.
 
#6 ·
I agree with Mark. You've done welding for a long time. Even though the welder wasn't working quite right,you're more then familiar with welding and as such even though I don't know you, I can't see someone like you leaving something that you thought was unsafe even if it doesn't look pretty.

I have the same welder in my work truck. It's not my personal welder, it's the school's welder along with the truck. I'm by no means a welder but I can put down a half way decent bead. I've welded a few things I thought I wouldn't be able to. The only thing you need to pay a little attention to with the flux core wire in that machine is to keep the whip as straight as possible, meaning don't have too tight of a loop or bend. The wire won't feed. Over all I think it's a pretty decent MIG.

There's really not too much wrong with a 120 volt welder except paying attention to the circuit you're plugged into. Voltage drop becomes an issue and it'll weld like crap on heavier stuff. At home I have a HTP 140, 120 volt. In my old house I used #10 wire on my welder circuit. My HTP weighs 140 pounds and most of that is because it has a big transformer with a lot of iron and copper windings. A lot of these portable welders have a smaller transformer with aluminum windings to cut weight and cost.
 
#7 ·
Try running 100% CO2 instead of the mix shielding gas, it will give you a little more penetration. The down side is the welds don't look as good as with the CO2/Argon.
 
#8 ·
Thanks for the responses. I decided to spend some extra time and put some more welds in anything considered structural/frame. I will just drill some extra holes and add in the "better" weld. I'm just glad I caught it prior to installing the subframe connectors and the mustang II suspension. In the end, I will spend about a week grinding down all the spot welds. Also, I might have to remove the upper cowling, I think it's off center, one of my fenders has a huge gap (3/16") while the other has 1/8" gap. Bugs the hell outta me.

Thanks again,

Slows
 
#9 ·
I have a Lincoln welder but mine is set up for 220V. Before I started welding once I switched over to gas from flux core I "read" the instructions & found that I had to rewire it. So far it has done all I needed it to do on the Mustang.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top