Overhead Plug Welding

[ghp]

Is is possible to do overhead plug welding?

The first image is what I am trying to accomplish on my Renault 5. I had the clamp on the screw.

When I finished, loosened the screw, the piece came down, the plate underneath was hardly marked. I could knock the welding out of the plug holes, they were as new.

This is not my first plug weld (but my second), the four top welds you see in the second image below can lift the car (I am repairing the jack lift point front left).

I'll try the advice given above, reducing wire speed and power.

Thanks,

Gerard

 

[malcolm]

It's less easy to do any kind of overhead welding, and the problem with plug welding using the technique on the tutorial page is the puddle could get quite big and fall out.

It's important to drill a hole big enough so you weld through the holes to the piece of metal behind without arcing against the side of the hole. As soon as you touch the side of the hole all the heat will go into that piece and will just fill the hole rather than add strength to the joint. Go into the surrounding metal at the last minute.

My advice would be to first try plug welding on clean scrap metal the right way up. Go with the tutorial page until you get the hang of it. If you were welding 2 sheets of 1.0mm steel then the welder power setting might be the same as one sheet of 1.5mm to 1.7mm steel. Your power looks way too low from the photos.

Get everything right there, then when you go upside down keep the power setting the same and increase the wire speed slightly. The guys suggesting a reduction in wire speed are probably using decent welders! A hobby welder needs faster wire speed to work the same when inverted.

Then follow the same technique as in the tutorial, though if you find big globs of molten metal dropping onto you (weld from one side so they don't actually hit you) then weld in shorter bursts of maybe 2-3 seconds at a time. If you need to do that you might find the power needs to go up slightly.

That's my guess.

 

[ghp]

One piece of advice that you should have given me also: "Don't forget to turn on the gas".

When I explained my problems to my son, who has learned to weld, he thought maybe my gas bottle was empty. I verified, it wasn't. But after I finished my second try, I noticed I hadn't turned it on. I couldn't believe my eyes.

The result was terrible, but it stuck, although I had to add welding to the sides. Again, a number of the plug welds did not stick. The holes were 6mm, but I didn't know you had to avoid arcing to the sides.


Still, a happy ending, yesterday the car passed the yearly technical check-up, which it had failed due to chassis rust.

But this was good practice, now I can start on my NSU, but there is no hurry there.

Thanks again, Malcolm.

 

[ghp]

I just read another overhead welding topic, in which someone advised using argon to reduce the fireworks. I have a bottle of argon, I just need a second gas regulator. I also had some molten iron in my ear, I heard it approaching my eardrum. A worrying sound it made, hair burning, but it stopped in time. I was using a full helmet, lying on my side. Since then, my ears are covered, I wear a kerchief while working, because my hair is too long anyway.

All pictures I made can be seen at the bottom of

My Renault5 Baccara (between 6h30 and 23h).

 

[malcolm]

Glad it's working better

The best kind of gas for car bodywork is a mix of 95% argon and 5% CO2 (or 95% argon, 3% CO2 and 2% oxygen). That reduces the spatter from the weld, and makes the arc much more stable than pure CO2. Pure argon is tricky to work with - don't use that for mild steel MIG welding.

I like your NSU.

 

[ghp]

You do? Well, so do I, but I'd like it better still if I can give it its original color, the previous owner, a lady, had it painted pink!! And a bad job it was too.

Right now I'm trying to remove the rear crossmember, where it is fitted to the body, the "splash shield"(?) is rusted through (see img_0965.jpg left).

 

[peterd51]

Hi,

speaking of overhead welding...

my nephew is a motor mechanic so we swap stories of what we've been up to from time to time.

A few years back he was laid on his back under a car welding the floor pan...

and the weld pool got a bit big...

and dropped off...

onto his overalls...

And when it burnt through his overalls it burnt his left nipple off!

He couln't raise his arms for weeks...

we did laugh!

Regards
Peter

 

[weldequip]

And when it burnt through his overalls it burnt his left nipple off!


we did laugh!

I'll bet he didn't at the time!
weldequip