Plug or spot welding

[kaw550]

I tried to repair the front of the passenger side wheel well last night. It didn't go so well.

Where I attached the panel to the inner fender it was okay. I got better as I went along.

When I changed sides I had trouble. I had drilled holes in the old metal and clamped the new metal behind it. When I started the weld, I pointed the wire at the center of the hole (new metal). It seems like it would just arc to one side or the other.

I varied the setting but it didn't penetrate the new metal.

Any suggestions or tips?

 

[allenfahey]

Bad ground?

 

[Explorer]

That would be my guess also. Always keep the ground as close as reasonable to what you are welding. Clamp or screw the pieces together. If it's jumping arc to the side, your new metal isn't making contact to ground.

 

[blazinchuck]

what was your wire feed speed? try turning it down a touch

 

[firehawk]

Get some scrap pieces and get it dialed in on those, then move on to the masterpiece ;D

 

[knack]

I put mine together with 3/16" steel pop rivets before painting. Plenty strong, but not stock looking - until covered with dirt.

 

[Dave]

Make sure the bottom layer is clean.

 

[gengel]

I see you said new metal - guessing it had some type of rust preventative on it - a lot of sheet metal has this or lube oil from the stamping press. Wipe with some metal prep or acetone and dry before welding.

 

[rustbucket]

The two most important things to consider when welding is ground and a clean surface. The clean surface applies to ground, as well. Make sure you clean the surface well just before welding. As gengel mentioned, you probably have some kind of rust preventative coating on the new metal. Sand the old metal clean and wipe with Acetone, and clamp the two pieces tight before welding. You will be amazed at just how much better your welds look with just cleaning the metal and getting a good ground.

 

[Rustytruck]

Make sure your ground is solidly attached to the piece without the hole. If your using flux core wire clip the end of the wire with side cutters each time before you start your weld. Make sure your wire in the gun isn't rusty. Rusty wire stops, starts and stutters.

 

[kaw550]

Thanks for the tips.

I am going to need to use screws to hold it in place.
Should I be creating additional holes for the screws or putting them through where I drilled for the spot weld? I saw a video on YouTube and the guy would take out a screw weld and repeat.

I think the isse may have been ground. Can I connect the ground clamp to a screw?
I am also going to make sure I cleaned the back of the original piece. It may be tough because I welded one of the three sides.

 

[allenfahey]

A screw won't make a good ground for welding. Body men at work sometimes use these if they can't get a clamp on the work..... http://www.harborfreight.com/magnetic-ground-block-30754.html

 

[JohnJohn]

I used a bunch of small c clamps from Home Depot instead of screws to hold the peices together.

 

[red hot71]

The way I did it was screw it together. One piece will have holes in it, put the screws there and weld up as you go,also a long set of vise grips can make things easier. If you are using weld thur primer after its final assembled before welding I was lucky enought to have use of a vacume spot sand blaster so you could spot each hole, the quality of the welds greatly improved. I'am guesting that the welder your are using you have used it alot? If it was flux core and now you are using gas did you switch the grounds inside the welder?Just asking.

 

[kaw550]

Well it's welded but it wasn't pretty. I went back and sanded all the surfaces I could reach and paid closer attention to the gound. It didn't seem be hot enough. The backide of the new metal did not show a lot of heat. I turned it up all the way but it didnt help.

I did go back and weld the seam to make sure it would hold.

Then I did a lot of grinding!