Originally Posted by u2builder
...a scarf joint is permitted on the ANYWHERE on the spar of a real aircraft except under a wing strut or other such attachment. Slope is 1:3 ...
Pretty sure the scarph has to be much longer than 3:1, perhaps more like 6;1 or 8:1.
And, in this case, it's probably easier to replace the spar. On yours, you did the right thing by putting the scarph out at the end.