Piet van der Horst

Piet van der Horst

In 1970 Piet made welding his trade en since then he never stopped learning about that trade. By now he is well past his retirement age, but not welding is still not an option for him. It is not just work, it is a passion.

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Gases for welding processes

Inert and active gases

Classification according to the standard In NEN-EN-ISO 14175 standard, gases are divided into main and subgroups. In this article we discuss four main groups of

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Cored wire vs High efficiency electrodes

A new product

On a beautiful June day I went to a shipyard in Brabant to do a demonstration with a cored wire. It was a wire filled with metal flux, with a diameter of 1.2 mm that was welded at the negative pole. Welding this metal flux wire onto the negative pole results in a very high deposition rate. Until then, the seams of a ship under construction were welded with a rutile high-efficiency electrode with an efficiency of 200%, a diameter of 6.3 mm and a length of 550 mm. High-efficiency electrode means that the very thick coating of the electrode contains a quantity of metal flux equal to the core wire of the electrode. This metal flux melts during welding and also ends up in the weld puddle.

What preceded it

The representative of the company I worked for at the time had listened very carefully to the introduction of this metal flux cored wire, which was unique at the time. At least 30% more deposition in the same unit of time, compared to the existing metal flux cored wires. It would also be a very good competitor to the high-efficiency electrodes. As often when theory and practice meet, this is not the whole story.

The demonstration

When we arrived at the shipyard it turned out that we had to weld in a half open building, something that is quite tricky with MIG-MAG welding because of wind and draught. But it was a nice day with almost no wind, so the demonstration could start. They had prepared two seams of about 3.5 meters. One is welded with the high-efficiency electrode. The other seam is for me to weld with the cored wire. Immediately two things stand out; the “electrode welder” sits on a wooden box with a hand shield in his hand and makes jokes with his colleague during welding. When he has to slide up he comes up a bit, kicks the box with his foot a bit further and in the meantime he continues welding. I am on my knees, bent far forward, looking at the arc in concentration. Welding helmet on and two hands on the gun to fill the seam as good as possible.
When we are about halfway it turns out that I am indeed faster than the “electrode welder”, but by one remark from him I know that this is not to be won even though I am faster. When I sit down and take off my welding helmet to wipe off the sweat, the electrode welder shouts to his colleague: “Look at him sweating”. At that moment you know your mission has failed 🙂

The best is not always better

The high efficiency electrode is a contact electrode. This means that the electrode rests on the workpiece during welding. The welder only has to hold the electrode holder and determine the angle of the electrode on the workpiece. Removing slag is not necessary, it will automatically curl off the weld. When changing the electrode, he briefly taps the slag out of the crater with the new electrode and continues. He can do this for a whole day without getting too tired.

It is very different when welding with a cored wire and certainly with one that has a higher deposition. To get all the molten material into the weld properly, you have to work very concentrated. A fusion defect or another welding defect is easily made. You can’t do that all day long. A welder will not last long when crawling over the material while holding a strongly forward-curved position.

Also, the weather during the demo was nice and quiet. With a little more wind you can forget about welding in a half open hall. The wind will disturb the gas flow and cause porosity in the weld. And not unimportantly, the appearance of the weld done with the electrode is usually much more beautiful than that of the one done with cored wire.

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