How do I avoid this?

[darren]

Actually first I need to know what this is.

mar-005.jpg (152.15 KiB) Viewed 1184 times

mar-003.jpg (100.17 KiB) Viewed 1184 times

It doesn't appear to be through to the wood but definitely is flatter than the rest of the finish. It kind of shows up through the leveling process but as I went through the micromesh and buffed it just got worse and worse. Happened on the last neck too. The sides of the fretboard are fine, sides of the headstock are flat and shiney, but these two spots are killing me.

I think I'm gonna string it up just to hear it for a day or two and then take it apart to redo the neck. The finish is Behlen's Rockhard Table Top Varnish, brushed. Next will be rattle cans, I've got to try something different.

[ken cierp]

That sure enough looks like classic sand through/cut through, to me -- very common around the perimeter of any finished surface plane. Might want PM dllutherie (nitro moderator) Dave is a great resource with much finishing experience.

[TonyinNYC]

Definite looks like sand through to me too. I have done it enough to recognize it!!

[darren]

Well dang it. the neck is gonna get redone.








but it is strung up and sounds so good right now nothing can get me down. :)

[Eric_K]

Sanding blocks are your friend. I hate them.
It wouldn't help on the heel, not enough surface to keep it flat. A block would help on headstock.

My number 2 guitar, which I finished a couple of weeks ago had numerous sandthroughs.
I sanded through while I was fixing sandthroughs.

Eric

[ken cierp]

It happens to the best I am sure -- I use pink foam insulation for my sanding block -- over the years and to this day I have to remind myself to take it easy on the edges.

[TonyinNYC]

I find the issue, particularly where Darren had his problems, is that the paper droops off of the sanding block. The only way to avoid this is to use spray glue to hold the paper tight to the block across the whole length of the sanding block. I had similar problems on my first guitar around the side port. I didn't make a slot head, so that was how I got around the sand through issue on the head stock!!