Welding Help

[Tulsa76bronco]

Welding blow through. I welded the wheel well back on but when fringing it flat noticed some thin areas that looked cracked, basically ground down too much trying to smooth it out. Lesson learned.
Now when I tried to quickly put a weld a bead on each side to bridge it just blew through. How do I weld this with wheel well so thin.

 

[Yeller]

Sorry I forgot about your text. Copper or aluminum plate and build it back up

 

[rocknhorse76]

I use a fairly thick piece of copper plate on the backside of the material and .023” wire. Keep the heat low and don’t dwell in one spot too long.

 

[gnpenning]

To expand on the previous replies.
If you have a short piece of copper pipe, hammer it flat, or split it and hammer flat. Bend to any angle you need and form a handle as needed. Same if you have a piece of aluminum.

Might be easier than buying one depending on what you have on hand.

 

[ntsqd]

On top of all of the suggestions, and sometimes instead of them I'll 'doodle' a gap like that. Think of successive spot welds, with a 5 to 10 count between each of them. You don't want to merely wait for the red to go out of them, you need them cooler than that.

It helps me to think of welding as being an "on-site casting process".

 

[Steve83]

I reduce the wire speed, and make very quick loops around the edges of the holes, pausing briefly between loops so the lips can harden & fill in the holes.

 

[jeffncs]

You can’t typically run a weld bead on sheet metal without warping the panel or blowing it out. Think of it as a series of 1000 spot welds.

Looking at the pics - your welds look cold which means you’re likely spending too long to build up a bead…which then blows out the thinner metal.

Bump the heat up a notch (typically 3 on the scale of 5) and set the wire speed to 25-30. Listen to your machine - it’ll tell you more/less heat and more/less wire based on a neat little buzz.

Keeping the old-new metal gap to about 1/16”, Angle the wire at ~30° to the surface aiming at the side with the thicker metal.

It takes a lot of practice and time to get it right but it can be done. I promise!

 

[jeffncs]

For filling in those holes - using the same quick clips I describe above, build up the sides of the weld back-forth until it closes up fully.