Learning Arc Welding

[syborg]

hi folks

ello.

heres the crack.
ive been welding up old gas bottles into wood burners using a guardsman pro craft arc welder.

i bought it way back in about 94 for about 80 notes from my ex,s mum catalogue.

so its not a good make or anything, just reliable.

top setting in 80 amps.

can anyone advise on settings for 3mm plate using this welder.

i do sometimes get decent welds but mostly they are blobby.

im using murex rods 2.5 mm.

not sure if i can change polarity.

any help would be great.

cheers

syborg.

 

[Welderpaul]

You need about 90 to 100 amps to run a 2.5mm rod. 80 amps will run a 1.6 rod, but not really big enough. You'll have to go down the route of v prepping the edges to be welded slightly to reduce the effective thickness to be welded, then lat down 3 runs to build up the thickness.
If your serious about it, you might be as well keeping your eye open for a cheap stick welder on ebay - they go fairly cheaply on there.
Your welds are blobby because there isnt enough amps to melt the rod and the parent material to get it to fuse properly.

 

[Haze]

I dont profess to be a professional but I would never use amps that high for a 2.5mm rod, and afaik I dont see my bro using that either and he is a professional, thats pipe welding though so I dont know how it compares.

personally I would run a 2.5 rod around 75 amps.

 

[Drains]

Haze, 75 A would be bottom-end, out of position, for the average 2.5mm 6013. For downhand welding, 90A would be more like it. Paul is high on 100A, but with skill and speed it's a reasonable current to use.

With 75A on downhand or fillet, i'd expect to see a lot of slag inclusion and some fairly lumpy welds.

 

[Haze]

im not sure what positions my bro welds in, i usually looked away from the arc

I only weld little things so generally i just tack things together

 

[English Lad]

I have been told that the arc length should be equal to the rod diameter, is this right? I am welding 6mm steel with 3.2mm rods at around 110amps on a Fronius Transpocket 2000. What the type of rods is I don't have a clue, haven't been taught anything about them yet.

Is there a formula for working out a starting amperage for a given thickness of material?