A set of doors will look like this when complete.

Length of doors vary slightly, process is the same for all.

One finish door looks like this

Weld the corners. This was MIG welded, TIG welding is preferred, as no grinding clean up is required.

Flip over and weld the other side

MIG Welded finish.

if MIG welded, we must use a grinder to clean up the corners. 

If TIG welded, no grinding is required

Grind the excess.

Careful not to remove too much material (we need the weld for strength)

It will look like this after the grinding is complete

If the corner is a bit like this, it is also okay as the rubber seal will cover it

Use an orbital sander on the outside face to remove any marks or scratches

Done!

The completed set of doors are now ready for powder coating