The Stovebolt Site Forums The Shop Area Paint and Body Shop New welder help

I have done very little welding. I need to do add some patch panels. I have a Lincoln Electric 120-Volt MIG Flux-Cored Wire Feed Welder from Lowes. The first time I tried to use it was to fill in some very small rust holes in my bedside. I thought I could just add a couple beads to the hole and grind it down smooth. Instead, it blew a hole through the bedside increasing the size of the hole. I was using self shielded, flux-cored wire. No shielding gas. What did I do wrong. I am concerned when I start trying to tack weld my patch panels I will burn through.

Read a book or watch some YouTube on welding, then practice, practice, practice.
Get some scrap sheet metal (or new if you have to) and lay down 10 beads on a flat plate just to get the feeling of the gun. Then work on different kinds of joints so you can figure out the settings as well as the methods.
You can't lay weld onto air, so holes need backing material. For tiny holes or gaps in thin metal you can hold a copper paddle behind it to prevent burn through.

What size wire are you using?


Mike

I was just reading another blog. I am hoping this is my issue. I am using 0.035 wire. From what I read, I need something smaller. Max of 0.030?

0.025 would probably be better. You could use 0.035 if you're careful. As mentioned, copper backing and then just "zap" the trigger. Zap, zap, zap, zap. Before you know it, hole filled.

I'm no welder, but I do weld... I'll tell you this- if you are trying to fill holes that were created by rust, the surrounding metal that you are trying to plug is so thin that it won't matter what size wire you are using. Better to cut the metal out until you get to thick metal, and weld a small piece in to replace the rotted area.

When I need to fill metal in between my spot welds on patch panels, where I am dealing with some thin original metal, I'll turn up the wire speed and turn down the power. The best thing you can do to try to weld holes, provided you can get in behind the panel, IMHO, is to get a piece of sheet copper and wrap it around a body working dolly and hold it right up against the back of your holes, and then weld the hole. Just like Mark said. The weld won't stick to the copper, and it will also work like a heat sink to help the original metal from melting so easily.

Welding with 110v is harder than welding with 220v, in my opinion. I have used .023, .025, and .030 wire in the limited sheet metal welding that I have done, and have actually found that .030 worked best to produce the best spot welds, but I am welding with shielding gas and an infinitely adjustable welder.

I'm still learning.

The metal has to be super clean! You might try using .023 wire, have your stick out on your gun a little longer (about 1/4") and touch the side of the wire to the inside of the hole, pull the trigger. Let that weld spot cool and do the same on the opposite side and go back & forth until the whole thing is filled. I just welded shut 14 trim holes in a door w/o any issues, and didn't need a backing plate...BUT I am using a welder that has finer tuning than yours and solid core wire, & gas...I gave my Hobart Flux Core welder to a friend and upgraded after doing the same thing you're having issues with.

______________

Janine
1965 Chevy Step Side Short Bed

I probably have the same welder as you do. One issue is flux core uses straight polarity and MIG uses reverse polarity (or vice-versa), but the polarity of the wire using flux core makes it penetrate deeper, thus it's easier to blow a hole in the work than with solid wire and shielding gas (MIG). That and the microscopically thin metal at the edge of the rusted hole. As was already mentioned, cut back till there's some meat there and weld in a patch instead of trying to fill a hole that keeps growing.

I am seconding, thirding and fourthing (are those even words 😅) the statements above. Do not weld on rust.

If is too hot hold a piece of filler rod in your other hand. Put the filler rod on the edge of the hole and weld the wire to the rod and the metal. ER 70S2 is mild steel filler rod.

Using a MIG sorta like a TIG. Now that's a cool idea!

Welded pipe for 35 years. Lol Same applies to any welding. Stick Tig Mig If you use stick rod for the filler you have to knock the flux coating off first. A hammer works just fine. If you want to fill holes with TIG get some silicon bronze filler. It is like gas welding but with a TIG torch. Plus that rod can weld galvanized without all the white and spatter you get with mild steel and galvanized.

But as Fox said You can not weld rust! No way . so you got to get back good metal.

If using a MIG you may find better results with solid wire and a shielding gas. Flux core is ideal for outdoor environment that would otherwise remove an argon/co2 shielding gas due to wind. (think farm repairs) If you're serious about your patch panels, get a welder with shielding gas. It will give you nicer welds with less splatter. If you're fixing a farm implement, who cares...

My suggestion for your welder setup in using the MIG (with shielding gas) is to FIRST AND FOREMOST set the heat for a full penetration weld when doing only one weld dot at a time. Then, if you have issue with blowout (on solid panel, not from the pitted rusty stuff) try increasing the wire feed speed. To explain, if you have enough heat for full penetration weld and not enough filler going in, it will burn away the parent metal. SO first, set heat, second, adjust feed speed to eliminate blowout, and fine tune from there. Oh yeah, sheet metal is a different animal. If you're gonna use a MIG, you may want to weld only one dot at a time, not a full weld pass. A full weld pass attempt with the MIG is about a guaranteed blowout as the panel heats up.