Tapping problem

[Kuna]

Looking at the back side of the cell:-I am using flux pen.The right line was taped well and the middle line all 3 small strips were not tapped. I tried again . not tapped. I tried with a new tapping bar, still not tapped and now the three strips in the middle line are look like burned and black in colour. I did not tried the left line yet. Is there any way to clean the black line? or the cell is still good to use with left and right lines are tapped?
Unable to updoad a photo as the SolarPanelTalk is not acceting photos taken by Iphone or Nikon Camera. (Image resize failed due to your image library not having support for this image type.) My both photos are in jpg.

[Mike90250]

sadly, the image function here is broke.
First, you need to learn soldering on copper wire and printed circuit boards. When you are real good, you can try cells. The metal deposited on the cells is very thin, and any slight mistakes in the solder process (wrong heat, wrong flux, wrong solder) damages the metal plating, sometimes even dissolving it into the solder.