Hassles with 2mm arc rods once rod is half - used up

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894runa
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Hassles with 2mm arc rods once rod is half - used up

Unread post by 894runa » June 5th, 2014, 11:13 am

HI,

I bought a pack of cigweld 2mm arc rods. I basically thought I could use them to arc weld thinner stuff and did fluke joining some 25mm SHS 2mm thick with only minimal blow - thru one side. Once the arc strikes on the thin stuff though, you definitely can't muck around!

But practising on some scrap 6mm plate, I found that once the rod has burned about half way down, it seems to start burning up faster than when I started the weld. I haven't noticed this on thicker rods - even 2.5mm ones - they burn up fairly consistently.

What ends up happening is that the start of the weld looks good and I get that consistent cccccc look and the arc nearly always strikes on the 1st scratch easily, but then about half - way thru the rod, the rod seems to increase it's rate of burn-up, making the arc length increase which leads to a high narrow bead and less penetration. I tried varying the technique including feeding it into the pool faster but it's like I can't keep up with it. I eventually just gave up when it started playing up half - way through and just got a new rod.

The hassle is that you end up only using half the rod.

So if you have any tips that would be great.

Rogers Cruiser
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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by Rogers Cruiser » June 5th, 2014, 11:39 am

are you holding the rod holder closer or even differently as the rod is burning down and your moving out of your comfortable position?

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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by chris_stoffa » June 5th, 2014, 11:43 am

Qwik thought, are the rods totally dry, stick them in a warm oven to dry them out for an hour and give them a try after that.
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Lux04
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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by Lux04 » June 10th, 2014, 11:47 pm

Hi 894runa,

Sounds like you maybe running to many amps.

If you can manage to run a stick down to about the last 30-40mm of flux & it is glowing orange, your running to many A.

2.0mm sticks should be run between 40<70 A.

In some circumstanses, with thin sections, it,s better to use a stick 1 size up at it,s lowest recomended A (or 5A less),, because of the higher deposition of filler.

As matter of interest, what machine are you using?

DJs Timber
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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by DJs Timber » June 11th, 2014, 12:07 am

I'd say amps are a wee bit too high, I get this with stainless rods when I need higher amps to get good wetting in weld but then feed quicker to keep consistent weld going
Cheers

DJ :)

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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by Harb » June 11th, 2014, 12:21 am

The performance of 2mm rods is going to change dramatically as it burns up.......
2mm is not a lot of rod, the cross section area of the filler metal is just 2mm, and the heat soon takes over and increases the burn away speed.....its just like the metal you are welding.....it welds easy when you first strike an arc, but as the metal gets hotter you start blowing holes through as it melts easier......
Just weld a bit, stop.....let the job cool a bit......weld on a bit further, each time chipping away the slag.......repeat
You may be able to drop the current down a bit, but make sure its not at the expense of penetration.....

894runa
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Re: Hassles with 2mm arc rods once rod is half - used up

Unread post by 894runa » August 19th, 2014, 9:52 pm

Sorry haven't checked in this thread for a while. I'll try some of the tips suggested and good point about the rod going fluoro orange means the amps are too high as that's exactly what's happened a few times - I've got down to almost out of rod but what's left has been glowing orange which I've never seen with thicker 2.5mm rod I've used before. I remember I even had one 2mm rod start to curl up and bend while I was using it making me think something obviously wasn't right.

The machine is an old buzzbox weldmate sp240 I think 160 amp. It's a 15amp plug but I do run it from a proper 15 amp circuit. I've done a fair bit of stuff with it mainly just practice but unfortunately being the cheaper and less fancy end of the scale means the only guide to amp setting is a sliding needle on a gauge with one side of the gauge showing job thickness and the other showing rod thickness so it wouldn't be very accurate and impossible to set to a specific number of amps.

I've been testing the 2mm rods on the 2mm SHS to see how that goes & basically it's been crap. Arc is a ***** to start & the bead looks rubbish but I am guessing it's an earth problem due to paint on the metal (yes I am bloody lazy with prep) as I can jump from that to the thicker 6mm plate (not fully prepped but also not painted) and the arc is dead easy to start using the same settings and gives a much nicer stringer.

Anyway thanks for the tips and I'll try and post up some pics.

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