When self-taught beginners begin to weld 2 parts at right angles, then most make one mistake. It all starts with a tack, so before tacking, take a square and set the parts at 90 degrees. In this position, put an oven mitt. remove the square and start welding. This is not worth doing, the details will not be at right angles, now I will tell you about this error and how to do it right.
It is important for beginners to know. Tack is a short weld seam or welding spot. As soon as we remove the electrode, this welding spot begins to cool down and go from a liquid to a solid state. See 3 photos above.
At this moment, by analogy with a snowball, the welding spot begins to sharply decrease in volume. It becomes like a piece of snow after molding a snowball, a little less. And the tack has already connected 2 parts, which means that when the tack cools down, the tack starts to pull these parts abruptly. Now I'll show you what will happen.
Let's make a welding experiment as an example. Put the plate at 90 degrees in the square and make a small tack. We now know that the potholder cools down and decreases in volume. Look what happened - the potholder just pulled this plate down the side of its volume. The right angle is badly broken. In this position, you cannot scald. But how to do it right? Look.
We will not expose 2 parts at right angles. And we make the angle from the side of the future tack a little more than 90 degrees. We make an oven mitt. when it cools, it pulls the part inward, itself adjusts the parts to a right angle!
Now we apply a square, adjust the part exactly along it, put tacks on opposite sides, and only then scald the structure. I learned this important information from Soviet books on welding when I was still studying. Then, when I started to work, the knowledge of this trick - that the parts pulls the tack in her direction when cooling down - helped a lot.
So remember always this analogy with a snowball - the potholder decreases in size and pulls on the details. So we make an angle slightly more than 90 degrees from the side of the tack and in this position we are already grabbing.
Another small plus of this method is when, after tacking, the parts are adjusted already at 90 degrees, with this shift a small gap forms between them.
You should also remember this and figure out what gap to set initially, so that after adjustment it becomes exactly what you need. But all this will come after several such works. An understanding of the practical correct application of this trick will come.
Share the article with your friends - click on the icon just below on the right, the article will be seen by your comrades in classmates or in contact.