Trying to weld, I’m terrible!

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rr4406pak

rr4406pak

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Trying to weld in some floor patches in my 69’ Dart. Using a MillerMatic 251 MIG welder with .030” wire. Can’t get a good weld for the life of me (as you can see). Been trying the whole day. I suck. Blowing holes through the floor. Turn the voltage and speed down and now the weld just piles up in ugly blobs (and still blow holes here and there). Ended up just grinding them down to see what I was doing. YouTubers make it look so easy, no idea what I’m doing wrong.
Would these ugly stitch welds hold though?
Any help is greatly appreciated. I’m so frustrated I want to give up… :-(

F0407B42-0683-41F5-BA79-40CA7A392A89.jpeg
 
You are using too heavy a wire. That requires too much heat to melt and makes a mess of sheet metal. Get some .023 wire and tips and try it again using lower heat.
 
IF it 18 ga. or even thinner, it takes an experienced guy to NOT use .023 but that takes gas and being out of the wind!!! Look at the CHART and be sure you are set up right with everything. Weld about 1/2 inch, skip aways helps, not to worp. Hand eye coordination,right amount of wire sticking out, wire spool speed, amps. PRACTICE on some scrap!! Mig wants clean metal!! Good ground!
You can do it!!!!
 
I feel your pain... go light and use gas if your welder will accept it. I practice on scrap or even new sheet metal to work on techniques

Good luck!!
 
Practice on scrap, a lot of practice. You may have better luck with the tip at a 45 degree angle to the floor to keep the heat from getting to hot in the sheet metal.
 
Spot weld it. It takes a while but it works I did my whole floor and trunk in sections. I would weld long enough to get a good penatrating puddle and let off go to the opposite side and do it again just keep bouncing around so each side has time to cool by the time you get back to it. You cannot run a bead on sheet metal with a mig welder.
 
Your pretty close to dirty steel with that weld. Clean farther away and is the other side undercoat or oily? It will melt and mess up the weld. Start the arc on one panel and drag to the other instead of starting on the joint and getting blow thru. Also u cant cleanly weld rust. my 2 cents.
 
Also get something that generally "will not weld" such as copper if you can jack it up against the weld area. If you have some scrap copper tube, hammer it flat. Use anything you have to to get it up against the weld, blocks, jack, prop, even of wood, etc
 
Prep and fit is the key, also it takes longer. The upside is less/no grinding. If your welds are too big, move your hand more or let go of the trigger sooner. The metal must be immaculate and no rust trapped at the joint. Left side of pic, the metal is too dirty. You want to be a welder, not a grinder.
 
That explains why it was so difficult to weld.
I’ll get a spool of .023” wire and give it another try.

I was ready to take up another hobby. Lol
 
Here's another vote for spot welding sheet metal. It takes forever but it works. I am a total noob but managed to weld in the new spare tire well this way. Gas and .023 wire are your friends.
 
As mentioned, a flattened piece of copper as a backer will allow you to get more heat in the seam without blowing out. It acts as a heat sink. It is also the berries if you blow a big hole, you can weld against the copper to stitch the hole closed and it won't stick to it. Should be videos on utube. 023 wire will work a lot better on the thin stuff too
 
All I can add is that your metal in the pics is not clean enough to weld and like mentioned above make sure the back side is clean as well.
 
What kind of wire are you using (flux core or solid) and what gas if solid? It matters because the polarity is different between the two. DCEP or DCEN and you physically have to switch the cables on the machine to match which wire you have.
5769FEB4-ACFB-48BE-804F-52C2CDD22DD0.png

straight from the owners manual.
 
Using the correct gas makes a big, bid difference .

Argon /Carbon Dioxide mix is what you need.

Screenshot_20220919-232035_Gallery.jpg


Not straight Carbon Dioxide (Co2).

Top of Picture: Not
Bottom of Picture: Better

DSC00689.jpg


4 key points of welding.

Heat
Angle
Distance
Speed

The amount of Heat in relation to thickness of material.

The Angle of the gun to the work.

The Distance of the gun away from the work.

Speed of Travel as you are moving along.

Heat, Angle, Distance, Speed.


How to get neat welds:


Should sound like eggs frying when welding and everything is working right.
 
I would also add that you're not "terrible". You're inexperienced and using incorrect parts/methods. However, even so you HAVE SUCCEEDED in joining two pieces of metal together, however ugly the welds may be. So you have done "that much", you just need to work on the details.
 
I have to use .030 flux wire because I have no place to weld out of the breeze and other issues with my 30 year old mig. NO gas.
I screw the sheets down with small metal screws, and pretty much spot weld till I get it covered. Also realize if you are welding a new sheet to an old sheet that has somewhat rusted over the decades it is thin!
Good thing is all I ever have to do is smaller patches, NO quarters, just floor pans are the biggest pieces.
There is a lot of difference in how a good machine does over one with issues>
 
Harbor Freight has a pretty good copper "spoon" to use as a heat sink if necessary.

I use a scrap door or hood to practice on, especially from the era of your car.

That way you get used to the thickness and quality of the metal you will actually be welding when it counts.

You can also use that to practice pain ting and other body work.
 
Spot welding works for me it helps clean the metal and you can use the previous spot as a heat sink to start your next spot. Clean as good as you can but some stuff just has to be cooked out to clean. The heat from the previous spot can help with that. Also if you burn through don't try to fill it in while its hot. Let it cool then come back use the previous spot where the metal is thick as a heat sink. Add a quick spot then weld somewhere else and come back after it's cool. Repeat. Check out Fitzee's Fabrications on you tube.
 
George Jets said:
Using the correct gas makes a big, bid difference .

Argon /Carbon Dioxide mix is what you need.

View attachment 1715988153

Not straight Carbon Dioxide (Co2).

Top of Picture: Not
Bottom of Picture: Better

View attachment 1715988158

4 key points of welding.

Heat
Angle
Distance
Speed

The amount of Heat in relation to thickness of material.

The Angle of the gun to the work.

The Distance of the gun away from the work.

Speed of Travel as you are moving along.

Heat, Angle, Distance, Speed.


How to get neat welds:


Should sound like eggs frying when welding and everything is working right.
Click to expand...

Forgot to add vision, i cant see well without a good light. Made a big difference for me.
 
Backside needs to be clean, and that undercoating seems to really cause problems with the weld. An inch or more of clean metal on both sides will help. Take your time,Rome wasnt built in a day.
 
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