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Discussion Starter · #1 · (Edited)
When I try and plug weld, the puddle doesn't build up well. I'm afraid to hold too long, I don't want to blow through. I'm also afraid to turn the heat up for the same reason

This pic is me trying to fill the hole for almost 5 sec. I'm using the HF titanium easy flux 125 with .30 wire on its lowest heat setting, and medium low wire speed.

Wood Tool Gas Household hardware Motor vehicle
 

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For starters, I'd practice first on scrap the same thickness, and adjust your settings. That way you don't screw up a project.
 

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Discussion Starter · #3 ·
For starters, I'd practice first on scrap the same thickness, and adjust your settings. That way you don't screw up a project.
I have been. Same results. Did a test plug on the car to see if it would be any different. It wasn't.

any feedback on why this might be happening? I've never plug welded before, but its not my first time welding in general. Tried different speeds and heats.

FWIW, this is lower cowl and firewall I'm working on right now.
 

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Secondly you need to clean all the paint off the base metal and the other part around the hole. Is your gas on and flowing well? Do you have the parts grounded well?
I may be wrong but I think he’s running flux core.
 

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I have the same welder. Practice on some like thickness material. Mine sounds like sizzling bacon when setup right.
 
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I may be wrong but I think he’s running flux core.
:eek: More wire speed. Or less heat more wire. Hard to say with a less than optimum welder. If your burning a hole you generally need more of something to fill it.
 

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Discussion Starter · #11 ·
Yeah, flux core. Base metal is ground clean. Good ground. I ground a spot clean for the clamp.

totally blanking, but do I need to grind clean the area on top where the hole is too? That wouldn't fix my "not building up" problem, but good point.

currently using lowest heat setting. Will try a little higher.

also have a welding clamp with copper bottom for heat dissipation coming. That should help, but I don't want to have to rely on it.
 

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For a guy with little experience in welding, a gauge and tank of argon/CO2 will make you look like a journeyman compared to what you're trying to do now. A worthwhile investment.
 

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For a guy with little experience in welding, a gauge and tank of argon/CO2 will make you look like a journeyman compared to what you're trying to do now. A worthwhile investment.
Have to agree. Welding with flux sucked but with gas and solid wire it made welding easier and looked a whole lot better.
 

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When I’m plug welding, I use the next voltage setting up from what I would use to butt weld the same thickness of metal. For instance, I have a Hobart 140 with voltage settings 1-5. I use voltage setting 2 for butt welding 18g metal, and use setting 3 for plug welding two 18g pieces together. Wire speed is intermediate. This forms a nice weld for me, takes 2 seconds to fill it in. If I was welding 18g to 14g, I would turn the voltage up to setting 4. It does not burn through the metal, as you have two pieces of metal to absorb heat. Especially so if using a copper backer. I suspect your voltage is too low.

If I were you, I would drill a bunch of holes in scrap metal, and practice plug welds, and adjust the settings to find the right setting. As mentioned previously, definitely weld bare metal to bare metal. This includes the metal around the plug hole. This has been my experience as a hobbyist, I’m by no means a pro. Hope this helps.
 

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It appears to me that the top of the frame has paint impurities, and you were starting in the middle and working your way out. You shouldnt need a backer plate for your hole. Try cleaning all that mess out with a grinder or flapper wheel so everything is shiny metal then try small circles working your way to the middle.
 

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Make sure your tip isn’t half clogged with burnt metal hanging on. Pull the trigger and watch it feed without welding to be sure the wire is feeding effortlessly. The spool could be too tight or slipping in the rollers.
 

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The pic looks like you are starting the weld in the middle of the hole. In optimum conditions with a nice welder that might be the best way to go (don’t know).
I am also limited to a flux core welder. I had good results by starting the weld pool at the perimeter of the hole and working the bead around, then filling the middle.
 

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Much happening here and youve gotten some great feedback. Key thing is to practice on scrap pieces of similar material.
Start at an edge not middle and perhaps try a bit smaller hole. It seems a bit on the large side. I usually go about 1/4 diameter. Heat up, wire speed up and move smoothly and quickly. That's kinda where you need to be. Practice will make it better.
I used to have a small 110V Miller with flux core. Great little machine. Replaced with a Lincoln and solid core / gad Nice improvement to all my welds,
Good luck !
 

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This isn't creeping precision TIG on beer cans. MIG was designed for production work, with the first application on certified aircraft landing gear. A 3/8" plug weld should take under 3 seconds. IMO if it's taking you longer, it's also heating everything hotter (and softer), so step it up. More wire to fill and more heat to get it laid-in. Heat is fine if you have the wire to soak it up, but your speed must increase. That's what the practice is for.

And, yes, rosette or plug-welds have 98% strength around the perimeter. Filling the center is to save finishing work or putty or appearance. Do what works for you and the project at-hand. Good luck!
 
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