So long as it is a two part filler, it has a hardener (catalyst).

Yep it is, however, I will stick with the filler I have now and train my patience 😉

That looks pretty darn good to me @peebee!

time required to do the fretwork and set-up = 2 days.

There was a time , not that long ago, where my fretwork looked like my guitar body right now 🙄

Use a small block to wrap the sandpapers around, if you just use it with your fingers, you will be sanding grooves into it all instead of keeping it flat. The devil is in the details! This what I did…   Read more»

I’ll dig it out and take a picture. 

@boo You mean something like this?

Where abouts in the world do you reside

I live in Belgium

@boo I am so grateful that you take so much time to explain in detail, even repeat things to make me fully aware of what I should be doing. I admire your dedication and patience

@boo it is rustins mahogany grain filler. The instructions on the can says : leave overnight to harden