Plug welding round bar

[Yamhon]

I want to plug weld some round bar into plate; both mild steel. I believe I heard somewhere a technique where you create a hole larger than the round bar into the plate, but only half way through and centered within this you drill a hole all the way through the plate, of the correct size to take the round bar.

The idea is to leave a channel of the difference in dimensions between the larger and smaller drill bits to hold filler material when you plug weld from the back of the plate.

I can't remember where I heard of this, or saw it. Does anyone do it like this? I think I'll be using 12mm or perhaps 15mm round bar.

How do you approach this, any tips or suggestions?

 

[Wonderweaver]

Yeah i can see the logic in the method. You've got to go in hot keep the puddle wet till it fills .

 

[Dcal]

What's it for?
How much load does it need to take?

What I do is drill a tight hole, then countersink it and put a bevel in the bar.
When you fit it up you have a tight joint that needs little clamping and has a proper v prep.

Bit like the joint on the hand wheel below.
I didn't bother beveling the bar as it's taking no load and it's was mostly to help me see where I need to put the weld.
But if the bar was prepped you would have a nice grove to drop your weld into.

 

[Yamhon]

That could work. Plan on making a simple jig to bend flat bar. Mostly it's just welding 12mm or so round bar onto a small piece of plate. I think your approach of using a countersink will be much simpler.

 

[gaz1]

you need arc to weld that up by the way

a much better one to build but you also need arc to weld it up

 

[gaz1]

still need an arc welder for these but much stronger in build at least with the one above and the second one the bender can be thrown into a draw and forgotten about

 

[Yamhon]

Don't have MMA capabilities yet; need to get a new electrode holder and test my Stamos on MMA setting see if that still works. I was going to bevel each side with a countersink bit and then hammer the round stock in for a tight fit then weld either side on full power.

Doesn't have to be a permanent solution; but I fancy making one and can make use of one for bending smaller size flat bar and round stock.

 

[Dcal]

If it's a tight fit it will be fine.
If it breaks it will be easy to weld it again.

Just do it.

 

[Yamhon]

If it's a tight fit it will be fine.
If it breaks it will be easy to weld it again.

Just do it.

Need to have a rummage see if I have the right size stock I can use on Tuesday when I'm next over at the garage.

 

[Parm]

you need arc to weld that up by the way

a much better one to build but you also need arc to weld it up

Yep, the Clarke 151 won’t have enough power for 12mm bar or 15mm bar

 

[Parm]

I want to plug weld some round bar into plate; both mild steel. I believe I heard somewhere a technique where you create a hole larger than the round bar into the plate, but only half way through and centered within this you drill a hole all the way through the plate, of the correct size to take the round bar.

The idea is to leave a channel of the difference in dimensions between the larger and smaller drill bits to hold filler material when you plug weld from the back of the plate.

I can't remember where I heard of this, or saw it. Does anyone do it like this? I think I'll be using 12mm or perhaps 15mm round bar.

How do you approach this, any tips or suggestions?

Did you ask your tutor?

Be interested to hear what a professional would have advised

 

[Yamhon]

Did you ask your tutor?

Be interested to hear what a professional would have advised

No; while I can get a tutor to phone me, that's only supposed to be for course related help. Should be off to welding center soon, so would rather ask the people there, that way at least they can show me if they have any tricks whilst I'm there... not sure if I'll be able to use the Esab machines when not being assessed, but there is that also.

 

[Parm]

No; while I can get a tutor to phone me, that's only supposed to be for course related help. Should be off to welding center soon, so would rather ask the people there, that way at least they can show me if they have any tricks whilst I'm there... not sure if I'll be able to use the Esab machines when not being assessed, but there is that also.

I rarely need to but I can speak to welding instructors on the phone

????????????????

 

[Dcal]

@Parm I agree a Clark 151 won't have enough power to weld it properly but if the bar is tight in the hole the weld will not be under much pressure so will probably hold.
If it does fail that is also a valuable lesson.
It's a simple repair and @Yamhon might have a working stick welder by the time it lets go.

We can spend all our time over thinking things, buying all the right kit, worrying about it or we can have a go.
Hardly safety critical and it's better than just laying beads down for practice (although nothing wrong with that)
If it was something that could cause injury I would not be proposing "having a go"

you need arc to weld that up by the way

There isn't a steel welding process I can think of that won't weld the joint.
But I agree it needs to have enough power and stick would be a excellent choice.

 

[Yamhon]

Dare say I could probably use a thinner diameter piece of round stock.

 

[Dcal]

Won't help.
It's the plate that will be the limiting factor and the thinner bar will probably fail in bending.

 

[Wonderweaver]

Yamhon just give it a go do what think might work this is the only way you learn. Theory learning is good and important but is useless unless it's put to practice. All you need is a pivot point which dictates the radius and a lever with a stop. For simple bends in round bar or square bar I had a piece of 12mm plate 50 x 100 ugly fillet welded to rectangular tube. Then I had a smaller diameter tube with a 16mm hole drilled into it that slotted over a piece of round bar. You could move the plate on the tube for different size stuff and lock it with a nut. Also change the radius with different size circles. It looked horrible but it worked.

 

[slim_boy_fat]

still need an arc welder for these but much stronger in build at least with the one above and the second one the bender can be thrown into a draw and forgotten about

My toes were curling when I saw him using that grinder....

 

[Yamhon]

Yamhon just give it a go do what think might work this is the only way you learn. Theory learning is good and important but is useless unless it's put to practice. All you need is a pivot point which dictates the radius and a lever with a stop. For simple bends in round bar or square bar I had a piece of 12mm plate 50 x 100 ugly fillet welded to rectangular tube. Then I had a smaller diameter tube with a 16mm hole drilled into it that slotted over a piece of round bar. You could move the plate on the tube for different size stuff and lock it with a nut. Also change the radius with different size circles. It looked horrible but it worked.

Yeah I'm going to knock something together, at the very least it'll give me more experience measuring up, cutting, drilling steel, weld prep and welding - all good stuff.

Ordered a piece of 8.9mm round stock and an 8mm drill bit with the theory I can drive the round stock into the smaller hole to get a really tight fit up, then I'll weld both sides of the plate.

Thanks for all of the input, appreciate it.

 

[mtt.tr]

Your machine isnt hot enough but honestly if its a good fit im pretty confident it will hold.