The secret is that the heat and cooling from welding will shrink the metal around the weld seam to some degree.
How to tig weld sheet metal without warping.
When welding thin metal the main objective is to avoid warping burn through and excessive heat affected zones while still ensuring the weld has enough mechanical strength for the application.
The best two electrodes for welding auto body sheet metal is either ceriated tungsten or thoriated tungsten.
That heat spreads out making the metal expand.
Tig welding is an excellent example of the less is more premise producing strength without adding mass and mess.
Ditch a 1 8 inch tungsten electrode for something much smaller like 1 16 inch tungsten.
The fact is that no matter how good or careful you are metal will warp when you re welding on sheet metal.
How to weld auto body sheet metal with a tig welder.
The more metal inserted into a joint the more susceptible it is to distortion.
Yes it is challenging.
If you re welding thinner materials like automotive sheet metal it is more critical that you keep the heat to a minimum when welding.
This restraint creates high residual tensile stress that causes the weld to act like a stretched rubber band with the workpiece holding the ends figure 1 for this reason when the clamps that hold the workpiece are removed the base metal is allowed to move or spring.
Only reduce or control it.
When mig welding sheet metal it is important to set the proper parameters to prevent warping and burn through or else it will create excess heat and easily blowholes on the metal.
We ve heard all of the tricks in the book but none of them completely stop the warping.
October 4 2019 by.
Top ways to keep metal from warping when welding.
Learn why mig pulsed mig tig and pulsed tig are the ideal choices when welding sheet metal.
Keep in mind during the welding process it is important to direct the arc right at the center of the weld puddle and don t do movements like whipping or weaving as it may cause warping and burn through quickly.
Learn some techniques from fabricators bodie stroud and josh.
When welding steel this weld bead is laid down at around 2 500 f 1 370c.
I did use some sort of backup at the seams to prevent burn through but did not expect that to control warping.
I had to tig long seams in sheet metal quite a few times making my muller flasks furnace parts etc.
Tig welding is preferred where practical because it is neater and cleaner than mig welding which introduces new material into the weld joint.
Mattm warped metal when welding is a constant struggle we all deal with regardless of thickness of the material.
To prevent warping it is important to get the the pieces clamped into position and make many many tacks.
The weld wants to shrink as it cools to room temperature but is restrained from doing so by the adjacent cold base metal.
