Help with welding

[jason.k]

Ok guys here is my problem. I have used #8 3/4" sheet metal screws holding my rear floor pan in place. So today I went out to the shop to practice my spot welding before I touched the bronco. I didn't have any luck. I got a good butt weld that I could not break it just bent the metal. Got a good plug weld and it held. Problem is I don't have either of those welds to do. My question is when you drill through 2 pieces of metal with the screws mentioned above I do not get very good penetration. I did 7 screws and they all could be pried apart with a flat head screwdriver. I repeated this process several times and adjusted head and wire speed with same results. I called my neighbor over to give me some lessons and he is a very experienced welder with a few builds under his belt and he couldn't get a good weld on this little hole either. So what is the technique you guys are using? The only way I got this to work was pull a screw and then use a much larger drill bit to drill the top piece of metal then I could get to the bottom piece and build up much like a plug weird. Any help is appreciated.

 

[Hazegray]

I would use a copper plate for a backer behind the hole if possible. I have flattened out a 1/2" copper pipe and held it behind the hole while welding, moving from outside towards the middle. The weld should not stick to the copper...

 

[Skiddy]

try short bursts, also might try starting a little off to the side of the hole

 

[phyler]

The only way I got this to work was pull a screw and then use a much larger drill bit to drill the top piece of metal then I could get to the bottom piece and build up much like a plug weird. Any help is appreciated.

This is exactly what I did. I used a 1/4" or 3/8" drill bit to make the hole in the top metal. Not too big of an issue. Drilling the bigger hole in the top metal also allowed me to fine tune the fit ever so slightly as I was installing.

Sent from my Venue 8 7840 using Tapatalk

 

[hankjr]

FWIW, I used a HF spot weld cutter to make larger dia holes in new panel only and in between screws. Welded rosettes in those for strength and just plug welded the screw holes to clean them up.

Hank

 

[bronconut73]

fwiw, i used a hf spot weld cutter to make larger dia holes in new panel only and in between screws. Welded rosettes in those for strength and just plug welded the screw holes to clean them up.

Hank

/\/\this/\/\

 

[bronkenn]

I use a pneumatic punch to put the holes in. They're pretty cheap and save a lot of time and sore hands from drilling. Astro makes good ones and they also double as a flange tool for marrying panels together. Very useful tool in the shop. Like the others I also weld up the screw holes to finish it up. Ken

 

[kip60]

As Ken said. I used a pneumatic punch from HF. Used the screws to hold everything in place. Screws are every 3-4 punch holes. Once punches are all welded. then I start taking out screws and welding those in for cosmetic reasons. Punches are all structural.

 

[Justafordguy]

X3 on the pneumatic punch, worked great for me and is much faster than drilling.

 

[jason.k]

Thanks guys. Looks like I'm on my way to harbor frieght to get a penumatic punch. Love this sight!

 

[jason.k]

FWIW, I used a HF spot weld cutter to make larger dia holes in new panel only and in between screws. Welded rosettes in those for strength and just plug welded the screw holes to clean them up.

Hank

What is a rosette?

 

[hankjr]

Basically a plug weld, but looks like a rosette due to the way the metal builds up as you work around the diameter. The larger diameter hole makes I easier to start arc inside hole and then build out to walls and then in a circle.

I'm out of country on bidness but can get some pics when I'm home later this week

Hank

 

[redfishtony]

As Hazegrey stated get you a piece of copper pipe and flatten it out. If you can get to the backside put the flat copper plate behind the hole and weld it up. If your having issues with them coming apart just weld them a bit larger than the hole diameter. You may need to turn your welder up a bit also but with the copper behind it shouldn't burn through. May take a little practice. Good Luck

 

[jason.k]

Basically a plug weld, but looks like a rosette due to the way the metal builds up as you work around the diameter. The larger diameter hole makes I easier to start arc inside hole and then build out to walls and then in a circle.

I'm out of country on bidness but can get some pics when I'm home later this week

Hank

Hank thanks for the answer and yes I like pics. Helps me understand things a little better

 

[jason.k]

As Hazegrey stated get you a piece of copper pipe and flatten it out. If you can get to the backside put the flat copper plate behind the hole and weld it up. If your having issues with them coming apart just weld them a bit larger than the hole diameter. You may need to turn your welder up a bit also but with the copper behind it shouldn't burn through. May take a little practice. Good Luck

I will practice this method this weekend. Thanks

 

[LilMixedUp]

while you're at Harbor Freight, they have a cooper backing tool in the welding area with a handle already attached, was pretty cheap and works perfect for this type of job

 

[sykanr0ng]

When you ask for the copper backing tool you may find they know it as a copper welding spoon.
Well worth having one in your toolbox.

 

[hankjr]

Thanks guys. Looks like I'm on my way to harbor frieght to get a penumatic punch. Love this sight!

while you are there, grab as many spot weld cutters as you think you will need, then double that (unless HF is real close to you). nothing more frustrating than getting in the groove and then breaking the cutting bit. they are reversible but too cheap to not have a few extra lying around

Hank

 

[jason.k]

while you are there, grab as many spot weld cutters as you think you will need, then double that (unless HF is real close to you). nothing more frustrating than getting in the groove and then breaking the cutting bit. they are reversible but too cheap to not have a few extra lying around

Hank

They are about 15 min away but I quickly learned I was going to need a few. I think I have stock piled about 15 of them in my tool box now but every time I walk in there I buy a few more. I have lots of metal to replace! I think the only thing I'm saving is rear wheel wells, inner quarter panels, fire wall and...... Well the rest will be replaced I think

 

[jason.k]

Ok after practicing this weekend these are my results. first pic is from the top side. bottom row is using #8 sheet metal screws with a welding spoon behind the holes. the top row I used a hole punch and the metal underneath did not have a hole in it so a plug weld. Second pic is the view from the underside. You can see with the screws and a welding spoon most of them did not get great penetration and the plug welds did. that being said I tried to pry the two pieces of metal a part and the screw holes did hold together.