Removing finish in control holes

[GearBoxTy]

I tried searching but couldn't find anything but I'm sure this has been asked before!

The CTS pots I have for my VIP body won't fit the holes and I suspect it is due to finish build up in the holes.  So, I am going to ream the holes a little to get them to fit.

My question is: to reduce or eliminate paint chipping, do I ream from the top of the body or from the control cavity side?

 

[pabloman]

Go from the top down. The other way is a recipe for disaster.

 

[Verne Bunsen]

Go from the top down. The other way is a recipe for disaster.

+ like infinity. A reamer is fine, but a piece of sandpaper wrapped around a dowel (or a pencil) will also clean that out in no time flat. Just go in from the top and rotate it a few times at a go checking often for fit. Avoid up-and-down / in-and-out motions. Sorry, no way to say that without double entendre...

 

[Verne Bunsen]

double post...

 

[GearBoxTy]

Go from the top down. The other way is a recipe for disaster.

+ like infinity. A reamer is fine, but a piece of sandpaper wrapped around a dowel (or a pencil) will also clean that out in no time flat. Just go in from the top and rotate it a few times at a go checking often for fit. Avoid up-and-down / in-and-out motions. Sorry, no way to say that without double entendre...

Just wrap it?  Is there an easy way to secure the sandpaper to the dowel?

 

[pabloman]

Just by holding it towards the top of the dowel or pencil. You could probably wrap it with masking tape at each end but it's really not necessary. In fact if it starts to come unraveled while working it's kind of a good thing. It's a very rudimentary tool. Very effective but extremely simplistic. Don't over think it.

 

[mayfly]

Go from the top down. The other way is a recipe for disaster.

+ like infinity. A reamer is fine, but a piece of sandpaper wrapped around a dowel (or a pencil) will also clean that out in no time flat. Just go in from the top and rotate it a few times at a go checking often for fit. Avoid up-and-down / in-and-out motions. Sorry, no way to say that without double entendre...

Just wrap it?  Is there an easy way to secure the sandpaper to the dowel?

When I had to do this (string ferrules in a Tonar finished body) I attached the sandpaper with double sided tape.

 

[TonyFlyingSquirrel]

First, countersink the holes on the face of the guitar, this will aid in preventing chipping.

I use the pencil/dowel method also, but I sandwich the body between my knees while seated, hold the sandpaper on the dowel and make very small, non aggressive vertical circles to sand slowly as to prevent chipping, and to remove material slowly, frequently checking for proper fit of intended components.  When they "just" fit, I go a few more strokes and it's usually enough.

Depending on how much material has been removed, you may wish to re-countersink the holes you just worked on so that when you put potentiometers through them from the back, that you don't risk any potential "chip outs".

 

[Ace Flibble]

I'd just like to throw in that with the thin poly finish Warmoth uses, you should definitely take care to only move away from the surface of the guitar (i.e. down through the hole or just spin around in it if using the dowel + sandpaper or rounded file technique), and I'd also put some masking tape on the surface of the ugitar around the hole just as an extra little bit of insurance. Thin poly can chip suddenly and drastically.

But for future reference, with nitro, wax, oil, and thicker poly finishes, you don't need to be anywhere near as careful. You can just take a rounded file to a control hole. So if you ever find yourself doing this to a non-Warmoth guitar, a simple rounded or rat tail file thrust back and forth will do just fine.