Greetings to all subscribers of our channel!
Whoever reads us for the first time is a blog for self-taught garage-country cottages in welding and locksmiths. Here are collected practical useful tips that will significantly shorten the path for self-taught people to normal results in working with metal.
When you just start welding metal, then after the first tacks you are surprised. It seems to have exposed the part exactly, as it should remain after welding, and after several tacks, this part moved away from its original position. Why it happens?
I'll show you a very clear analogy, I have already shown it in old publications.
Why even a small tack can move the part from its original position. Above 3 photos - the first photo is the moment when the welding tack is still warmed up. Then it begins to quickly cool down and change in volume, it becomes less than it was hot.
And the potholder has already tied both pieces of iron, and at the moment of cooling through the potholder there will be a sort of attraction of these parts to each other. This can be clearly seen if you put the potholders on only one side of the part, as in the top photo.
We needed these examples with tacks to get to the main topic - why the metal leads and the geometry of the product changes after welding the products. How to solve this problem, what is written in the old welding textbooks? Why is there nothing new in the old, but simply in the modern, everything has been rewritten from there.
Imagine now that the weld seam in the volume of the deposited metal is tens and hundreds of times larger than the tack itself. This means that the tightening forces at the seam cooling down will be much greater.
It can be said that both parts to be welded will stretch towards the top of the weld. It always happens, there is no getting away from it. There is simply a set of recommendations on how to minimize these deformations.
These are the tips we learned in old welding books. If it is known in advance that after welding the parts will still be pulled towards the seam, then you can initially make a reverse bend on the tacks. After welding, the parts will come to the desired position.
How to calculate this bend - only empirically, if you weld a lot of such parts, then it is quite possible to adapt.
Consider the sequence of welding seams, if there are several of them in the product. Include logic and assume that the next seam should compensate for the deformation from the first, and not reinforce it.
Let's not forget about the volume of the welding seam itself, in simple words, a thick seam tightens deforms more. Therefore, where it is not necessary, you should not make thick seams.
That is, it is desirable to use different diameters of the electrodes, depending on the thickness of the metal. Simply if you weld 1.5 mm metal with 3 mm electrodes, then the deformation itself will be greater than from electrodes with a diameter of 2 mm.
Temporary stretch gussets can be used.
After welding the structure, but only after the seams have cooled completely, these temporary braces are removed. They quite help, you can safely apply.
And the most important thing is practical experience, which cannot be replaced by any books. You need to see in practice how this deformation works and also try to reduce it in different ways.