On Mon, 09 Dec 2013 22:18:47 -0000, John Rumm wrote:

On 09/12/2013 16:22, Gefreiter Krueger wrote:
On Mon, 09 Dec 2013 16:16:33 -0000, John Rumm
wrote:

On 09/12/2013 16:02, Gefreiter Krueger wrote:

Any advice on how not to melt the workpiece?

Lower current, smaller rod, more time between welds to allow more
cooling.

The welder I've borrowed is very adjustable, but lower current makes the
rod stick to the workpiece. The higher current makes the arc work
better. I guess I have to do quicker goes.

That might just be an effect of using damp rods.

They've been indoors for 24 hours and still do it.

And how to stop the welds
being brittle?

Good penetration,

What do you mean by that?

The weld needs to fuse properly into the existing metal. A combination
of adequate current and rod size for the material in question good
technique. You want the filler metal to fuse with the existing, not just
stick to it.

It does a fairly good job of that, it's the welding material itself that is rather brittle as soon as a slight force is applied to the joint.

and not incorporating slag into the weld. Use an
appropriate rod for the material being welded. Observe preheat and cool
down recommendations for the material.

I've just ordered some mild steel rods, and I think the workpiece is
also steel, although some is galvanised. It's the non galvanised stuff

Make sure you grind off all the galvanisation where you are welding.
Where a full respirator as well if welding galvanised steel.

it's not sticking to though, and mainly the welding material is breaking
in the middle, but sticking to both pieces. The rods I'm using at the
moment I've no idea what they are, they're what my neighbour had left
over from a year ago welding vans.

Watch this, a demo using a cheap stick welder for general purpose
fabrication:

http://www.youtube.com/watch?v=Iy5GC1zOatA

I see he's using 150 amps. Mine is only 60 amps.

--
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