Thank you for your support Ken, Alexis, Rick, Ferry, Stephen, PrzemoL, Guy and Richie!
I'm not yet done with the struts ...
But I made some progress, here without glue.
I wanted to put the struts with thinner ends and brass pins into the bigger wing holes, but this doesn't work in a controlled way.
After I checked the full resolution pictures again I noticed, that there are bolts visible on the other side of the wings and also some metal mounts can be seen on every strut.
So I drilled to the wings and glued 0.6mm nickel silver micro tubing pieces into it. Again a lot of work.
I filled also the big going through the wing holes and put there also those tubes.
So now the struts are sits safely with 0.4mm brass pinned and it looks nice.
But I had to shorten the struts again!
And now the reason for my post, again a question.
That hard yellow resin is not bad for sanding after glueing with CA - both have the same strength.
But I have a bad experience with priming this. It has such a smooth, waxy surface (yes it is cleaned) that paint literally rolls off. My trusty Alclad primer (which bites or etches into plastic) was not very successful.
This was the result of masking during my Sopwith Triplane project (I used then a plastic part).
I know, that Ken has build glider kits from SPIN. Ken, what have you used?
There is or was a special resin primer from Gunze, but I can't find that product in a shop.
I prefer a airbrush product over a rattle can.
Thanks,
Frank