Hello, guests of our channel for self-taught welding and locksmiths. Reading the comments on the articles, I sometimes come across questions where people are interested in how to weld thin metal to thick with an electrode. Let's take a closer look at this issue.
The experiment will be extreme! I will take a scrap of 10 channel bars and a small piece of galvanized tin. I do not know the thickness of this tin, but here it is far less than a millimeter.
Let's complicate our task. We will not weld flat, but we will make a corner joint.
First, set the welding current. We set the current when welding thin to thick on thick metal. You see 2 seams, the upper seam is low current, the lower one is fine.
Here you can focus on a simple pattern. The maximum seam thickness for welding in the down position is 2.5 times the diameter of the coated electrode.
We just light up the electrode and move slowly, watch until the width of the seam behind the electrode is maximum. You can determine by eye-2.5 diameters, or you can estimate with an electrode cinder, well, or with a whole electrode!
Let's grab the tin to the channel. It is very important here that there are no gaps, otherwise it will immediately burn out. But there are still small gaps here and there, I definitely didn’t feel lazy to adjust! See the very principle of such welding.
Here is an analogy between an electrode and a weld. The seam in the section is shaped like a fungus. When the electrode burns and melts the metal, the deepest penetration is in the center. The farther from the center, the less penetration.
The energy decreases towards the edges of the weld pool. Therefore, we should only slightly moisten the thin metal with the edge of the weld pool. We direct the penetration center into the thick metal, and slightly hook the thin one with the edge.
We welded a can and a channel. Not without jambs, let's see what happened. Now let's enlarge the photos of the seam.
We got 2 places with errors. At the very beginning, there was a small gap, plus the time for heating the thick metal to a normal weld pool. Natural burn-through. Well, in the middle of the seam I made a slight lack of fusion.
For the rest of the seam, everything turned out fine. We have completely fused the can with the thick metal of the channel.
I cooked with a rutile-coated 3 mm electrode. The welding current was 100 amperes.
Do not scold too much in the comments! I could fix these 2 hot spots of the seam, but I didn't, let everything be fair.
This is the principle of welding a very thin metal and a thick one with a simple electrode.