At the start I was considering of installing a truss rod (hot rod), but I came to the conclusion that all rod's are too long to fit the (short) neck and I would encounter problems near the neck joint. (it's a very cheap and poorly constructed guitar, it's not even a dovetail neck joint).
I also thought of the idea of making a single acting truss rod myself, just like I did for my seven string, but I dumped that idea because I don't want to invest too much time/work in the project.
So I went with the carbon fibre rods.
But instead of routing two narrow channels for the reinforcements, I laminated the reinforcements with a piece of hardwood (meranti). (I updated my website with additional pics)
This results in a very stiff bar. I even stood on it and it bends less than 0,5 mm in the middle. (the bar is 300 mm long)
I don't know the long term effect on the neck, but if it doesn't work out it's not that bad (remember it being a 13 dollar guitar)
It's really odd that the guitar broke along the glued joints (fretboard and scarf joint). It's like the glue became brittle through the years.
you can also clearly see that the glue wasn't spread out evenly.
Thanks for the tip on the string angle over the saddle. I'll remind that.
The color will be black matte. No rosette, inlay or anything, just plain black.
Cheers,
Joten