Grinding down a weld on a formed workpiece is and probably will remain an intensely manual operation.
Grinding down welds on sheet metal.
Keep your grinding disc nearly parallel to the metal so the grinder smoothes out the edges of your weld even to the sheet metal.
Grind it almost flush maybe leaving a very slight crown.
Using a grinding wheel on a weld.
To achieve this initial stock removal and if the surface finish is not essential the metal worker might choose to use a simple grinding wheel with an angle grinder.
Better surface finish than a grinding wheel or fiber disc grit for grit.
High where overgrinding is a concern such as thin walled sheet metal.
But the devil s in the details.
I ve always used angle grinding discs to finish welds but the ordinary grinding discs are very coarse and difficult to control so i tended to grind almost back to the parent metal then use a little body filler.
At every process upstream most precision sheet metal fabricators employ at least some level of automation.
It s better to leave just a little extra rather than go to far.
But there s no getting around it.
You must avoid touching the panels with the grinder as they can get too thin really fast using this tool.
The aim here is to grind the joint down to a level and continuous surface with the rest of the parent metal.
Overhead work where the weight of the grinder is important.
This is a slightly worn they come with straight edges 40 grit flap disc.
Hold the grinding disc as level as you can to the piece of metal.
The last step is to grind down the weld with a 3m reinforced weld grinding wheel.
Welds tend to have dips up and down so holding the grinder at an angle could cause it to gouge into the metal.