Hmm, ok. That's where I'm looking and the diagrams depict 15:1. The doublers are 10:1. If the inspector is happy, I'm happy.AC 43.13 Section 4 1-39 on page 1-15, talks about the scarf joint. In that section, it states that the No grain deviation steeper than 1 in 15 should be present in an outer eighth of the depth of the spar. The scarf joint can be 10:1 according to the inspector that checked me. I may have gotten off easy as my airplane only weighs 560lbs MGW.
Can you post some pics of your scarfing jig? I'm trying to figure out a good way to make one. Thanks.