A hot topic for self-taught beginners in welding is loop welding, correct and even welding. Welding ready-made round loops in place is not a big problem even for beginners - grabbed exactly coaxially along the guide from the professional pipe and slowly weld vertical seams.
Another thing is to prepare these round loops for such welding, namely, to weld the pads to them correctly and evenly. They are also called platycs, flags, ears, etc.
There are many options for precise assembly and welding, many do it even by eye, but this is not our option. You need to do it accurately and efficiently.
We have 2 round loops. Now we will cut the platforms themselves. In this case, the pads were cut from a strip, a strip 40 mm wide. The length of each pad should be equal to the length of the loop segment. Let's cut 4 platforms, according to the number of loop segments.
Immediately we will make 2 additional platforms, they are, as it were, superfluous, but they are needed for centering when placing in front of the tacks.
Now let's remove small chamfers on these areas. We do very little chamfers, the strip thickness is 4 mm, and we deepen the chamfer by about 1 mm. This is not for easier welding, but for more accurate alignment during assembly.
Grab the strips on a flat metal surface. Let's make an even gap between them by inserting a 3 mm electrode with a coating
We will grab strips to the loop, which are located diagonally. The second diagonal strips are our auxiliary centering strips. In order not to confuse and not grab them, you can make marks on them, for example, with chalk.
When we grab it, do not confuse which pad will go to the box and which will go to the sash. That is, which platform is for the daddy of the loop, and which is for the mother.
We put a loop in the gap between the platforms. The loop here lies firmly, evenly. Now we grab the required pads to the loop. We put on 2 potholders.
When we make potholders, we firmly hold the loop itself, since the potholder can pull a little. We grabbed it, cut off the tacks of the pads themselves to the surface.
We grabbed the plates, we remove 2 plates for centering until better times, for the next loops. We also grind down the potholders of the pads to the hinges with a grinder to make it easier to weld. Now I will show you what kind of accuracy I got.
We lay the line of the square between the sites, bring these sites together and see what happens. Perfect alignment with millimeter precision. Of course, we are not building an airplane, but it is better to strive for this!
That's it, now we scald it. First, the seam opposite to the tacks, and then the seam on the side of the tacks. The hinges can be welded at an angle so that the slag does not interfere.
Here's an accurate way for all beginners and experienced people.
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