My favorite threads in this forum are build threads. I did not document every step of my build, partly because I was focused on work, and partly because I made a few processes take super long.
I have posted a few pics, and here are a couple more.
I used bondo to seal the mdf edges. Once I got familiar with how to best apply only the amount needed, it was pretty easy.
Strong and sands super smooth.


I finished all pre-paint steps on one cabinet, tried to paint it and incurred a couple hiccups. The main one being the inside of the woofer cavities obviously don't spray well so i will finish coat those with a brush and some flat paint.
After three light coats of Rust Oleum painters touch flat black primer, I sanded a little too early (lesson in patience) and got a couple grooves in the surface from the clogged sandpaper. So i got a can of the Rust Oleum filler primer. That worked great.
This is the filler primer smoothing out the side. I also used that product on small table easels I made for my kids. I used left-over cheap plywood. Made for a pretty smooth surface after 3 or 4 coats.

Thanks for looking.
Ben