How's my welding?

[ajgriffin]

Hey guys!

I think this is my first post here, so

I'm working on a firewall for a 71 Chevrolet Suburban. This is my first time welding sheet metal and my second time using my welder so I'm definitely a beginner. That being said, what advice can you guys give me on my welds? The firewall and patch panel are 16ga, I'm using a Millermatic 140 Autoset MIG.

Settings:
Wirespeed - Autoset for .030
Voltage - 8 volts

I think I need to do a better job spacing my patch to help with penetration and obviously I missed that the backside of the existing sheet metal had some rust that I should have cut out. Is there anything else you guys see that I'm doing wrong? How can I go about fixing it?

Fitting up the patch panel:


Close up of patch fitment, some areas have a larger gap than others:


Close up of the front side of the welds, sorry about the rotation:



Back side of the welds (again, sorry about the rotation):

[ajgriffin]

Here's what it looks like after I ground down the welds. Sorry, I wasn't thinking about the iPhone picture rotation problem when I took the pics.





I used a 4.5" 80 grit flap disc on my corded grinder and it seemed like it took quite a while to get it flush. Maybe a more aggressive grit would work faster without causing problems? 50 or so? I've also considered if I should switch over to a TIG instead of the MIG. Any thoughts or suggestions? I'm not looking to become a pro fabricator or anything. Don't count on doing much (or any) aluminum, just some sheet metal work on my trucks here and there.

[motolife313]

Move a 1/4 that amount each time you tack. Your moving way to far ahead. You wanna stack it over half way over, more like 3/4

[acourtjester]

For grinding the welds use an angle grinder with a cutoff wheel, walk the wheel along the weld using just the edge of the wheel like 90 degrees to the weld surface. It is quicker and generates less heat, and as usual jump around not a constant grind on a long weld.

[akpolaris]

For grinding the welds use an angle grinder with a cutoff wheel, walk the wheel along the weld using just the edge of the wheel like 90 degrees to the weld surface. It is quicker and generates less heat, and as usual jump around not a constant grind on a long weld.

I would not use a zip wheel as a grinding wheel, that isn't the designed purpose of that thin wheel. I would use a regular grinding disc to take it down then cleaned up with a 120 flap disc

[John T]

Is there anything else you guys see that I'm doing wrong?

It looks like your a little cold.

Thats are some pretty big deposits for a "spot" weld.

You can also try a quick circular motion with the gun... kinda like a plug weld.... that will keep the weld a little flatter..

but overall, I'd say turn up the heat a taste...

Be BOLD.

[12V71]

It looks like your a little cold.

Thats are some pretty big deposits for a "spot" weld.

You can also try a quick circular motion with the gun... kinda like a plug weld.... that will keep the weld a little flatter..

but overall, I'd say turn up the heat a taste...

Be BOLD.

Yep, doing the zap-zap-zap thing you want more heat to flatten those blobs, almost to the burn through point. Learning when to let off the trigger is the main thing.

[ajgriffin]

It looks like your a little cold.

Thats are some pretty big deposits for a "spot" weld.

You can also try a quick circular motion with the gun... kinda like a plug weld.... that will keep the weld a little flatter..

but overall, I'd say turn up the heat a taste...

Be BOLD.

Thanks for the tip! I'll try slowing down the wire speed and if that isn't enough I'll crank the juice up a bit. Thankfully, I have to cut that rust out so I'll have another section to weld up before the nice panel goes on.

[ajgriffin]

Move a 1/4 that amount each time you tack. Your moving way to far ahead. You wanna stack it over half way over, more like 3/4

Thanks for the tip! I completely forgot about the importance of placement first time though.

Yep, doing the zap-zap-zap thing you want more heat to flatten those blobs, almost to the burn through point. Learning when to let off the trigger is the main thing.

👍🏾 Makes sense, thanks for the tips. I'll give it a go again and report back.

[tapwelder]

Do what the said...but don't slow down.

[John T]

Thanks for the tip! I completely forgot about the importance of placement first time though.
.

probably obvious but I'll mention it anyway,
make sure you skip around to avoid overheat/warping... you can fill in the dots later as it cools.

also,
0.023 wire will help substantially*



*(just set the machine manually.... autoset wont be correct with smaller wire)

[smithdoor]

Looks great for first time.

Dave

Hey guys!

I think this is my first post here, so

I'm working on a firewall for a 71 Chevrolet Suburban. This is my first time welding sheet metal and my second time using my welder so I'm definitely a beginner. That being said, what advice can you guys give me on my welds? The firewall and patch panel are 16ga, I'm using a Millermatic 140 Autoset MIG.

Settings:
Wirespeed - Autoset for .030
Voltage - 8 volts

I think I need to do a better job spacing my patch to help with penetration and obviously I missed that the backside of the existing sheet metal had some rust that I should have cut out. Is there anything else you guys see that I'm doing wrong? How can I go about fixing it?

Fitting up the patch panel:


Close up of patch fitment, some areas have a larger gap than others:


Close up of the front side of the welds, sorry about the rotation:



Back side of the welds (again, sorry about the rotation):

[Weldalittle]

This might sound completely opposite of what you would expect to do, but try a little less than perfect fit up. Somewhat like that one in your second photo. Do it on some scrap first, of course. Not so big that it just blows a big hole, but a little bigger than your filler wire. As long as it's not an exact perfect fit up. What I've found is that it will leave you with less to grind off when done welding.

[david.junge.77]

Your getting there mate, I only wish I had the internet and forums like this when I was learning. I was like you leaving lots to grind from being to cold.

Even though I'm not ticketed welder, I was taught by my ship builder boilermaker grandfather and I totally agree with what everyone has said, and have done many car repairs, thin sheet jobs myself over the years.

I expecially agree with the small gap to allow penatration and the 2 pieces welded together stay properly welded after grinding.
I've had a boilermaker come to me to weld thin sheet as he just couldn't weld it, so there is an art in it.

As for grinding, as others have said use a grinding wheel first and work your way around a few times to stop the heat buildup.
Flap disc's do build the heat quickly and wear out quickly when used as a grinding disc, and just leave a small amount for the flap disc to carefully finish off.
The weld is always harder than the metal so be careful you don't roll off the weld and grind the metal accidentally, this is where good lighting comes in.

It takes some practice and I even undercut sometimes with the grinder and I've been welding for 30 odd years in the home shop and car repairs, and kick myself for it.

This picture is showing the penatration on the back side of my last job welding 0.6mm gal sheet metal, you want to see something like this when welding sheet metal.
The total weld length of these where around 700mm long each and there was 4, so it took some time swapping between them allowing cooling to minimize distortion.

Enjoy and have fun, you will have all your mates lining up for rust repairs, lol

[whtbaron]

I've been told ( but haven't had the opportunity to try them yet because they aren't available around here) that there are "Easy Grind" versions of the wire that will make it a lot easier to grind off the lumps. Expect it to be a lot more expensive than regular wire, and depending on where you are ( I'm in Canada) it may or may not be readily available. Might be worth looking into if you are doing a lot of metal finishing.

[david.junge.77]

That sounds good, I just usually use what ever 15kg spool is available cheap, lol

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