I like the sledgehammer I have, it worked perfect for the star nut on a fork and star nut installation, the weight of the hammer does the job and since in that application I was striking the pilot drift. very little effort involved and the light taps drove it in nicely, very controlled with an even and uniform depth. On the seat post, as it is stuck, I could probably clobber it and get nothing to break free with that hammer, but also run the risk of having a mis-hit and slide off, potentially damaging the frame tubes ?
I started sanding other areas of the frame and the test area I primed, one of the edges of the dropouts rubbed thru. But I figure I can build that back up with another blast of primer giving it thicker coatings when I'm ready for the rest of the frame. That and eventually I'll color coat it with the tougher engine enamel. With more coats, the engine enamel on other parts gets a texturing and isn't glassy smooth to the touch. Probably need to wet sand and polish that if that's what I really want. I actually prefer the rougher feel, it may not be as glossy as in the difference between a semi and high gloss, but the rougher feel makes me perceive it as tougher. It's a bmx not a carbon road bike is how I convince myself to just layer the coats and accept that it's a rattle can paint job and not a factory fresh or custom show paint job. My problem has always been that I don't know when to stop rubbing the paint finish smooth and have rubbed it thru on paint projects that I did earlier in my life.