Thx gents for the comments and likes.
I received my cup burrs and ofcourse tested them on a test piece.
I bought a 0,8 mm and a 1,2 mm and use them for 0,4 mm and 0,6 mm wire.
When you just cut the wire and then apply the burr you just get a nice bolt head which is counter sunk into the wood, just perfect. Right the 0,4 mm bolts for the frames, left the 0,8 mm for the frame to keel. I will finish all my outside bolt heads with it after finally sanding and scraping the hull.
@Jimsky this is a great tip, love it. The American Russian methode 2.0.
I directly see a second option, when you use it on a larger diameter wire you are getting a bolt head with a rove, I still need to properly test that.
For the rest it is working on the last fwd cant frames.
Step by step, only one remaining fwd cant frame to finish, it takes me about 1 hour for a set of cant frames to prepare and place them, now 15 finished and some 60 to go, pff where is the time of the block model.