Official Luthiers Forum!

I'm to the point of wet sanding the finish on my third guitar and had some questions as I started. What is a good sign that it is time to move on to the next grit? It's easy enough to tell when sanding lower grits but I find the higher grits harder to tell. My second question is about cleaning the surface between grits. I'm using KTM9 and I'm not sure about what product to use or method for cleaning the surface to make sure its clean for the next grit. I don't want to sand with a finer grit if there is residue from the previous grit still on the surface. In the past I used a damp paper towel to wipe the surface. And finally, what grit do you go to before buffing the finish out? Thanks for any and all answers.

_________________
Kyle

Changing stroke direction when you change grit can help you see when the scratches from the previous grit have been sanded out. That doesn't have to be a 90 degree change in direction, but it can be. For all finishes except shellac I wipe off with a clean rag and alcohol. I generally go to 1200 and then buff.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Going in opposing directions works well, but isn't always possible(tight areas, etc...), and there's always the chance that you'll "miss" a spot and have sanding scratches come back to bite you when you begin buffing.

I just listen when sanding, paying close attention to when the tone changes. An old-time(and excellent) auto body man/teacher taught me the method in high school auto body class. It works.

I clean the surface with "Bon Ami" foam glass cleaner, sprayed lightly into a paper towel, not directly on the surface. I swore-off of water-based finishes years ago, so test on a small area if you do try the Bon Ami, though I do believe it's safer than alcohol and other solvents.

Don't forget to change your water and soap between grits, also. Or better yet, have a separate container for each grit. Helps a lot if you soak the sandpaper overnight, before you use it.

Thankyou both for your replies. A separate container for each grit is a good idea.

_________________
Kyle