so, I tried a possum in a weak solution, and it slipped, what do you guys think to weak?? the rat in the strong solution, seem fine,

It's a lot easier to get barktan solutions too weak than you strong.

so do you think it slipped because it was to weak?

I would guess it was too weak and the pH wasn't low enough to kill bacteria and set the hair. You could try pickling first then bark tanning. That would probably be a safer method. Otherwise make the bark solution stronger and check it frequently and add more bark solution as the hide takes in the tannins.

thanks I will try the stronger batch,