Thread: Can someone post a video of how they can weld thin square tube with a stick welder?

I'd say you are probably being being too ambitious.

Start with 2.5mm SHS and 2.5 mm rod and get that perfect.
Then go to 2mm SHS and 2 mm rods get that perfect
and then try the 1.6mm tube.

I've been stick welding for a number of decades and still can't do 1.6mm without the occasional hole

Thanks Bob,

Sorry I meant using 1.6mm rods on the 3mm square tube. ( I think its 3mm maybe 2mm ill check that when I get home )

Cheers
Nick

Originally Posted by Njmpm

Thanks Bob,

Sorry I meant using 1.6mm rods on the 3mm square tube. ( I think its 3mm maybe 2mm ill check that when I get home )

Cheers
Nick

I would have thought that after an 8 week course you should be able to weld 3mm thick SHS with 2.5mm rods.

The tube probably won't be 3.0mm. That's a bit thick unless it's bigger tube.

Don't buy 1.6mm rods. They're hard to use. 2.0mm are OK.

Easier to hear what you're using first, i.e. no point giving advice on 1.6mm thick tube if you're actually using 2.5mm tube. Also, what dimensions are the flat bar?

Welding thick to thin is not ideal.

were in sydney are you what brand of welder ?

Appreciate the replies everyone.

I will double check the dimensions when I get home, working a 12hr shift today.
The 8 week course was a 2hr a night one night a week course. We were using several different machines and spent a little time on each.
Most of the time we were practicing running beads on the different machines on thicker material.
The last couple of days were trying to join thicker pieces together. Like I said probably just a basic intro to welding and we didnt learn to weld thin stuff together.
Probably should have got the exact specs of my material first before posting but didn't realise that I would be requested to do so.
I was hoping for someone to show me that it was indeed possible and how they went about it.
Just interested to see a skilled welder do it I suppose.

Located in Matraville not sure on the brand but ill check that when I check the specs of the material that im using.

Thanks
Nick

They had you working on thick stuff because it's easier.

Machine is just so we have an idea of whether the machine is going to make life harder.

I can (could) do 1.6mm material but it's frustrating and tricky with stick. I did plenty and kind of worked out what I needed to do but still got holes and messy welds. 2.0mm material is much more forgiving, 2.5mm material even more so.

With thin material, perfect fit up is critical. Perfect rod angles, perfect arc gap, perfect everything.

1.6mm rods are hard, they flick all over the place. Cut them in half to make life much easier. 2.0mm rods are doable as long as their amp range is suitable. ~2.5mm rods are doable """".

I would tape you a video for fun but I've never known how to do it. I guess if I bought a spare weld lens and positioned the camera on a little tripod behind the lens. Otherwise you'd just see a washed out white square.

Yes the 1.6mm rods are tricky but do work well with very thin material. Not necessary in this case and will make it harder.
I was thinking of just sticking my gopro in a welding helmet - anyone tried that?

Provided the flat bar is thicker, I'd be focusing the arc onto that fairly close to the tube, and letting the weld flow to the tube by the action of the heat.

If you've got pieces to spare, cut lots of bits of the tube to a short length, and practice welding them to the flat bar, changing where you aim the stick/arc for each one until you find a distance that works.

It is often a problem when stick welding fillets on thin material, in that it is tricky to achieve penetration down into the root of the fillet without burning through the walls of the base metal on either side. The common solution is to turn the amperage down, which then often results in the weld tracking against one side of the fillet or the other - leaving worm trails with slag inclusions.

A good thing to try in this case is:

• leave the amperage up high
• start the weld normally and makes sure the weld is involving both edges of the fillet
• quickly transition to an exaggerated drag angle (say at 45 or even 60 degrees), so that the rod is pointing back more towards the weld than the more typical 20 degrees

This pushes more weld metal into the fillet, reduces the tendency to track on just one side of the fillet, and reduce the risk of burn through on thin material. It also means that it is easier to wrap the corner of the weld to help with a neat tie in for the next weld.

And... if you want practice with manipulating rod angles, get some 2 inch (or less) round tube and start welding it end on to a plate.

Cheers

- Mick

Ok update,

i realise that I have made it even more difficult before I even started welding!
The tube is 25mm square 2mm thick however after cleaning back to bare metal with an abrasive disk I measured the walls and some are only 1mm thick!
image.jpg

Anyway, the flat bar is 38mm wide and 4mm thick.
image.jpg
Ive just rested the square tube on the plate as I didn't have another one cut and cleaned. This is the bracket I made just using flat bar as I couldn't weld the tube to it. I know the welds aren't good but I need the practice and it's fun actually making something.
image.jpg
What I have done is use a wire brush head on the grinder to clean off the coating on the square tube to maintain the thickness and as others have suggested I'll cut little pieces off and just practice welding them to the flat bar until I can do it.

I just thought that that someone who likes to make videos could show me how it was done so I had a good idea where to start.

Ill post some some of my efforts later haha

cheers again for the replies and tips,
Nick

Since it's painted, yep, the wire brush will clean it off. Gentle, gentle with the flap disc on thin material. Particularly on corners, they can take away a lot of material quickly. Actually, you can get good fit up with that joint configuration. Just need a square cut on the tube. Rest between welds or you'll learn about distortion.

Originally Posted by BobL

..........I've been stick welding for a number of decades and still can't do 1.6mm without the occasional hole

And here I was thinking it was just me!!!!

I've spent a lot of time welding rubbishy thin stuff like you're trying to weld 'cos I'm a cheapskate and recycle a lot of old junk. I use 2.5mm rods exclusively and find the best way to deal with it is to weld very short sections at a time, say 5 to 10mm at a time so it doesn't get too hot. Takes a while but it works. Needless to say, I have become adept at filling holes in it too using much the same technique

Stitch weld it and let it cool down.
Preheated metal burns through faster. Practice
till you get a feel for it, basically your
running a bunch of tacks along the intersection
of the joint.
Then run a bead over the top
using a tight side to side weave pattern
moving off the thin metal quickly.