Here come the "Fleetweld" stick electrodes

This note of June 5th - see later note for what I discovered... Anyway;

Heard of the legendary and slightly feared "Fleetwelds" and always wanted to try them and if possible master their usage. This complementary sample kindly sent by Lincoln Electric. These are the defining current variant, the "Fleetweld 5P".

The Lincoln website informs us that the "Fleetweld" family of electrodes started with the "Fleetweld 5" in 1927. They have been known since the late 1940's (?) as pipeline-welding electrodes, for which they are still used when modern automated processes don't pan-out.

They have a fearsome reputation, as the predominantly cellulose content of their coating ("wood flour" (sawdust?), paper fibres, etc) decomposes in the arc creating huge quantities of hydrogen which causes high arc voltages and a constricted arc giving deep penetrating power. Meanwhile, the coating converted mainly to a gaseous shielding leaves little mineral slag, giving a fast-freezing weld metal and little slag, creating the opportunity for some unique specific-to-cellulosics welding techniques/applications.

In appearance, there is nothing which sets them apart from other "stick"/SMA electrodes. The maroon colour and the imprint "FW5" are the only warning :-)

Further note - findings late June 2004

Took electrodes to try at nearby college, where various welding machines and facilities to easily prepare plate. Obviously, feeling very excited, as "moment of truth" approaching. What a finding it turned out to be...

No welding machine I could find would run these rods, the Fleetweld 5P's. I tried various inverter (contemporary power-electronic DC) welding machines. None would do it. Could draw arc to warm-up electrode end, but as soon as touched-down in root of V-prep for dragged keyholing run, arc immediately went out.

Hmmm.... Realised I was probably supposed to find something out here, and this was it...

So back to a certain company not wholely unconnected with these rods. "Oo arrhhh, there's reckoned to be only two types of machine which will run them. A diesel DC generator welding machine or a Lincoln Bullet. That's a three-phase motor spinning a DC dynamo." The diesel DC welding machine and the Lincoln Bullet amount to a statement that there is only one way to run these rods - to directly couple them across a DC welding generator.

These are proving to be some welding rods!

Final note to say, yes, I do know the "stovepipe" pipe-welding technique using cellulosics is regarded as something of a thing of the past. Apparently steel pipe strengths are higher, meaning thinner wall thicknesses, hence smaller more highly stressed welds where no part of the weld can undermatch the pipe for strength. This makes for hard weld metals and so on where the high hydrogen is really a problem. But has been interesting stuff to study.