Back in October, I countersunk the rear spars of the HS. I went to flush then 0.007” deeper as per section 5. I tested with a coupon in the same thickness as the skins and it seemed ok. The skins were dimples with the DRDT2 (and the dimples have for well on the front spar and ribs etc).
Since then I have primed the spars and skins and the HS is completed except for the rear spar.
Today I clecod in the spar but I’m not sure about the gap between the skin and the rear spar - i understand I shouldn’t expect the dimples to nest completely in the countersinks and Van’s doesn’t want you to do this (they want the dimples to lock into the countersinks for structural reasons).
But I am feeling something is not right here and the countersinks need to be a bit deeper? Perhaps the paint thickness made the difference. I have emailed Van’s and asked but haven’t heard back as yet.
Next step is I might remove the spar and drop a rivet in the countersink and see what it looks like.
Thoughts from the brains trust?
Here is a photo of the rear spar after it was countersunk - unfortunately no photos of a rivet in the hole.
Here is a photo of the skins against the spar - I have clamped it so it would be like it had been riveted. You can see quite a gap with a torch behind it. https://photos.app.goo.gl/KZ5gyGDY8jDA8Ycs7
And a second one, not clamped.