Nice seam - strong seam. Every welder knows this proverb, and it's true. After all, a beautiful seam, which has small scales, will be dense, and therefore of high quality. It is much easier to make such a seam on thick metal, but today I will tell you a welding method for thin metals. It will be useful for beginners, because for them it is the welding of thin metal that is most difficult.
It is better to weld thin metal with an electrode with a separation, so it will burn less. Electrodes for such welding are needed with a rutile or rutile-cellulose coating. In the photo, such electrodes of the brands MP 3, ANO-21, OK-46 are the best in their class. It's just that such electrodes are easily re-ignited.
An illustrative theory of such welding. The disc from the grinder will be in our welding bath, which turned out after the ignition of the electrode and the melting of the metal by the arc. The end of the handle of my hammer will be the end of the electrode!
We light the electrode, the metal warmed up, we got a weld pool. At this moment we interrupt welding, abruptly remove the tip of the electrode to the side. Through the mask, we clearly see the contours of the border of this weld pool. It is better to weld thin metals in a chameleon mask. Fixed a look at this border.
And here is the main trick of correct re-ignition. We light the electrode by bringing the lower end of the electrode 2-3 mm inside the weld pool boundary. This rule applies to electrodes with a diameter of 3 mm.
And so over and over again, we do each repeated ignition, going deeper with the end of the electrode to the size of the diameter of this electrode, deep from the clear boundary of the contour of the weld pool. Naturally, all this is done by eye, but following this technique, the welds will be beautiful and dense. Now let's cook.
I took 3 pieces of a profile pipe measuring 60 by 30 mm, thickness 2 mm. It turned out 2 joints. We will weld these joints with different electrodes for the experiment. I'll weld the right joint with an ANO-21 electrode, and the left one with a better quality OK-46 electrode. We brew with the same technique described above and see the result.
Cook with a separation point by point. The current is about 80-90 amperes, I do not have exact values up to 1 ampere on my device, so it's about in this range. The polarity is straight, minus the grip with the electrode, so there is less chance of burning. I know that in the books it is written differently, but in practice it is better to do it that way, it has been checked hundreds of times, and many experienced welders have the same opinion.
We welded both joints, beat off the welding slag. Now let's take a closer look at these seams. I will increase them several times so that the scaly seam is visible.
This is a photo of the seam from the ANO-21 electrode, it can be seen that the scales are very dense. the beauty and quality of this seam is pretty good.
And these are two photos from the OK-46 electrode, it can be seen that the scales are even denser. If not for multiple approximation, it looks like a monolithic.
Friends, I hope with my examples I have explained the correct technique for welding thin metal with a break. Try these rules and the result will surprise you. See you in new articles on welding for self-taught.