I am a little confused with the terminology I think. When you say stitch welding what do you mean. I understand the pulse cold metal technique for welding thin car body and then continuous welding seams for thicker metal, is stitching one of these or different?
Yes you are probably right the better welds on the 1.5mm practice pieces were probably when the metal was hot. I guess I thought that on high settings with a 185amp welder I would be able to use the pulse cold metal technique and still achieve good penetration (as I thought I possibly had done before) but it seems that isn't the case.
I haven't really done any welding completely upside down. I have welded sills and outriggers with vertical welds but not much horizontal completely upside down. Welding from above you can see the penetration on the reverse side quite easily. However, when working from underneath I am not sure what it should look like above on the otherside.
I am willing to listen to the way to do it but I tried running keeping the weld pool going for longer between pauses in one section of the repair and found that the edge where the outter sill will attach starting to bend and I worried. I then started to pause more. If the edge becomes bent then the outter sill won't sit properly and I'll really be in trouble. I think from what I have done and what you guys are saying that the pause method isn't going to work on 1.5mm, I am going to have to use continuous small sections but not more than about 15mm or the distortion is going to buckle the track.
The good news is I have just found a place locally that punches out metal parts from sheet metal and they have some 1.5mm sheet that they sell. Someone has picked some up for me so I now have more to practice on. So I can now practice with whatever recommendations you guys have. Once I have the correct technique I can then correct the repair on the vehicle.
Yes you are probably right the better welds on the 1.5mm practice pieces were probably when the metal was hot. I guess I thought that on high settings with a 185amp welder I would be able to use the pulse cold metal technique and still achieve good penetration (as I thought I possibly had done before) but it seems that isn't the case.
I haven't really done any welding completely upside down. I have welded sills and outriggers with vertical welds but not much horizontal completely upside down. Welding from above you can see the penetration on the reverse side quite easily. However, when working from underneath I am not sure what it should look like above on the otherside.
I am willing to listen to the way to do it but I tried running keeping the weld pool going for longer between pauses in one section of the repair and found that the edge where the outter sill will attach starting to bend and I worried. I then started to pause more. If the edge becomes bent then the outter sill won't sit properly and I'll really be in trouble. I think from what I have done and what you guys are saying that the pause method isn't going to work on 1.5mm, I am going to have to use continuous small sections but not more than about 15mm or the distortion is going to buckle the track.
The good news is I have just found a place locally that punches out metal parts from sheet metal and they have some 1.5mm sheet that they sell. Someone has picked some up for me so I now have more to practice on. So I can now practice with whatever recommendations you guys have. Once I have the correct technique I can then correct the repair on the vehicle.