Technical Sheet Metal Spot Welds

Is there someone around the New Braunfels / Austin / San Antonio area that would like to take a couple of hours on a Saturday afternoon to teach me what I'm doing wrong when I spot weld sheetmetal? i watch all the different threads and builds that make it look so easy. I'm sure its a simple trick, but I am not getting it.

VOH

 

what welder?

 

What is going wrong?

 

Are you using an actual spot welder, or doing rosette welds?

 

Are you talking spot welds or tack welds on sheet metal?

 

Sorry, i said spot welds, but stitch welds is a better description. I’m talking about butt welds for patch panels.


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Seems to be blowing thru a lot. Seems to be high welds, so it’s hard to blend in.


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Eastwood 135. Using argon/Co2.


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It sounds like the welder is set to high. Start on the lowest setting or up one setting. To blend in you will have to grind the bead

 

A stitch weld usually refers to welds made with a MIG machine with a timer that starts and stops the weld at preset intervals.
Sounds like you are manually tack welding butt joints.
Blowing through sounds like wide gap or heat setting too high for the gauge of metal.
High build could mean heat too low and no penetration or too long on the trigger.

 

How thick of wire are you using?

 

Yep that’s important

 

.023 .025 Wire for sheet metal and sounds like heat to high

 

Does that machine have a settings chart?
Is the polarity correct for mig welding ?

 

Does that machine have a hot start /soft start mode?

 

Welding new metal or rust old stuff? Or as is often the case new to old rusty stuff? That can be tricky as the old metal can be really thin.

 

Wire feeding too fast will do it every time.........for me at least

 

Practice on the bench on some identical scrap metal. Then go to the car.

 

Rule of thumb I heard years ago is 1 amp per .001" steel thickness. So, 18 Ga is about .049" I think so somewhere around 45-50 amps. I think I'd start a bit lower amps than that and do some practice pieces like suggested above and go from there. Hope this is helpful.

Lynn

 

Stop! If you are welding on the actual car you cherish and love more than anything in the whole world??Start by cutting up some scrap metal pieces the same gauge as your car and then practice a bunch. It is really easy to learn mig welding. You have to start by dialing the machine in properly the wire feed and heat setting have to be just right also the gas has to be flowing properly. The metal should be as close together as possible and likes to be clean. Sometimes also if the shop doors are open a good breeze can carry away the shielding quality of the gas making poor welds. You need to get the FEEL of welding to get competent at it ,then confidently weld on your ride. You do understand the tricks to weld patch panels in without major warping of panels.... right?