Any welders on the board?

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EvilScamp

EvilScamp

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I have a question about mig welds not penetrating.
I'm using .030 wire to weld body panels,sometimes the it will weld good(plug welds)and penetrate other times it won't!
It will just fill in the hole and as soon as i touch the weld to see if it held it brakes!
The heat is on 4 and the wire speed is up about half way,i can't remember where it's set right now.
Any tips or suggestions would be appreciated. :)
 
I'm no expert, but usually the problem is an unclean surface. Make sure both pieces are clean.(No rust, paint, or grease) You might also check that your ground is good.
 
You have a couple of things that may cause this. The most likely cause is not enough shielding gas while you are welding. You may think it is doing alright but you will have the results you are getting. Give me a little more info on what you are welding with. What type of welder is it? How old is It?( may seem like a silly question but it helps in figuring out possible problems) What type of gas are you using?
 
turn your wire speed down a few, and try it...and turn the voltage up or down from there.i run my gas at around 30" make sure its very clean (after grinding i wipe the panel with denatured alcohol)and that your ground is good. when welding your quaters, weld the upper seam (front to rear upper) in 1 inch sections about 4 inches apart and then go back and weld an inch more ,etc,etc until it is completly welded (this will cause very minimal heat warpage.you will get some warpage but very minimal)thiswill make it so you will not get the cracks and bubbles you get from just plug welding the panel (ive not fully welded the quater on one car i did and from chasis flex it cracked at the rear )
 
Thanks for the tips guys :D
It could be the wire speed,the area is very clean i made sure of that.
It welded real nice along the top but underneath around the wheelwell they kept breaking or about the time it filled in the weld would get to hot and fall out.
The main problem was the door jam,i had 1/4 inch holes drilled in the new panel the weld would come out real nice and fill the hole but as soon as i put a little pressure oon it to see if it held they would just break!
Any tips on welding upside down along the bottom and around the wheelwell?
 
I think you need to get the weld really glowing and rite before the point were the pool of hot glowing metal would fall, that is when you need to cut the juice and let it cool. it takes practice but you'll get it. one more way to tell if your doing a good job is to look at the back side of the weld( if you can see it) and see if you are getting good penitration. It should look burnt and you should be able to see exactly were you were welding (if you can see the back side of the weld that is).
 
Alot of the time, what I do when welding sheet metal, is I leave the power a little to high and I just pull the trigger and let off like your shooting a gun, I started doing this when I ran into problems with blowing holes in sheet metal. Just remember you dont have to fill the hole with one pull of the trigger.
It does sound like your getting too much wire when your pulling the trigger and can't find a happy medium. This might be because your using a thicker wire. I will just assume you are useing gas with your welder, Not just a flux core wire. If this is true I would try useing .023 wire. With this thickness I find it easier to turn everything down so I can find the "happy medium". You can also run the thinner wire through your welder with out having to buy new tips, It's not that detrimental anyway. You will find out that the wire won't load up on you if you try it. And it won't blow through as easy if you have too much juice. Good luck and I hope what I wrote makes sence. Josh
 
Like halfaed said going witth 023 would be easier for sheet metal. He is also correct on the method he is using to do sheet metal. You can spend the extra money and get a welder with a spot or stitch feature but that is all it is doing is cycling the output on and off, nothing you can't do yourself with the same or better results. The only thing about not running the correct size tip is that you may experience some erratic arcing. I have done way to many service calls on welders that people were complaining about poor welds that only needed a new tip or correct size tip in them. You have to remember that the tip is the main place the voltage transfer takes place for the wire. If not there you are relying on the liner (if its not a italian made welder with a plastic liner) to make that transfer of power. As for running the overhead welds, a little more voltage and a little less wire speed will get the job done nicely and give you a flatter weld. Just go at it in spurts so you don't burn through because the sheetmetal will get hotter quicker. A 75/25 co2/argon mix usually works the best with sheetmetal but if you are careful a straight co2 shielding gas will give you a deeper penetration
Carl
68 vert
St. louis
 
Use .023 wire and turn the wire speed down till just above where it will blow holes in the metal.Too much wire speed and you are not melting the wire and metal together and it just falls off.
 
75/25 argon/helium gives some of best sheetmetal welding you'll ever get. I'll give you a good sunburn also
 
no one mentioned that u need to stay away from flux core wire and drop the wire size to about 023 (030-035 &o40 are for welding thin plate
 
What is the down side of flux core, other than the clean up needed afterwards ? I'm not a welder but the only welding i've ever done was with a flux core wire. Seems easier for a beginner like me.Also it's just easier to carry around w/o that bottle. I just bought a Lincoln wire welder (flux core) that I can get the conversion to gas for.It's another $100.
 
I am not a welder, but I do dabble a bit. Flux core splatters. With sheilding gas, you get very little splatter. I bought the gas kit for my mig when I bought the welder, but I did not use it right away. I got crappy ugly welds. When I added the gas, even my welds looked pretty nice.
 
The flux core will actually work ok doing frame connectors and such. Clean up with a wire wheel will make it look almost as nice as mig. You can also but some stuff called anti-spatter that can be sprayed on to keep the spatter form sticking.
The down fall to the flux core is it's size. The smallest is .035 which is too large for doing sheetmetal. All you will do it burn through.
 
cudaboy said:
What is the down side of flux core, other than the clean up needed afterwards ? I'm not a welder but the only welding i've ever done was with a flux core wire. Seems easier for a beginner like me.Also it's just easier to carry around w/o that bottle. I just bought a Lincoln wire welder (flux core) that I can get the conversion to gas for.It's another $100.
Click to expand...

Flux core wire actually creates a hotter arc and the flux sprays off the end of the wire. Both of these conspire to blowing holes in sheet metal. As others have stated 0.023 wire and sheilding gas is the way to go. Also, I agree the 75% co2/25% argon is the way to go but 95% co2/5% argon will get the job done for a lot less money.
 
Thanx ! Those are the best explained answers Ive gotten.
Damned, reckon I gotta spend more money now !!!!
 
But once you do spend the money, you will love it. I also didn't know that about the tip size having to be correct, Sorry bout that!
 
EvilScamp said:
I have a question about mig welds not penetrating.
I'm using .030 wire to weld body panels,sometimes the it will weld good(plug welds)and penetrate other times it won't!
It will just fill in the hole and as soon as i touch the weld to see if it held it brakes!
The heat is on 4 and the wire speed is up about half way,i can't remember where it's set right now.
Any tips or suggestions would be appreciated. :)
Click to expand...

My first thought to this questions is your choose in Gases? How clean is the surface your welding? I prefer .025 hard core wire with a 75% Argon and 25% CO2 or a Tri mix Gas. What type of welder is it? Lincoln, Miller e.g.

welddoctor
 
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