Protecting the "holes" during wet-sanding

[Steve Sawyer]

On the current build, after completing the clear-coats, the inside of the pickup cavities seem to have a good coat of finish so I'm not too concerned about those. Ditto the peg-holes. However, the through-holes for the strings and screw-holes for the pick guard, control cavity cover and bridge might be an issue. How do folks prevent water from creeping into those holes and getting under the finish? I was thinking a drop of frisket mask might do the trick if I can get it in the holes, below the surface, but there might be a better way.

Thanks.

[Barry Daniels]

There is no perfect method for this, but here are the options I am aware of.

1) You can paint the inside of the hole with lacquer or shellac using a small artist's brush.
2) You can wet sand with mineral spirits. (I don't recommend this due to the hazards)
3) Dry sand with self lubricating papers.
4) When you get to an area with holes, use less water. Sand a bit and then immediately wipe the water out of the holes. Don't give the water time to soak in or load up the holes.

I haven't tried this but you might be able to seal off the holes with a small cut out circle of masking tape or scotch tape.

[Steve Sawyer]

Thanks, Barry. Seems that using a combination of #1 and #4 to be the simplest and most direct solution. I have some brushing lacquer that I could easily use to "paint" the inside of the screw holes. I hadn't thought of that, but that's to be expected - it's really the most obvious solution!!

[Gordon Bellerose]

I always end up re-drilling most of the holes.
There doesn't seem to be a real good way of sealing them before wet sanding.
I use some very thin packing foam under the guitar to protect it.

[David King]

What about filling the holes with plasticine or mastic?

[Peter Wilcox]

I drill most of the holes after the finish is done (bridge screws, tuner screws, pickup adjusting and cover screws, control cover screws), though I try to mark them out beforehand. I got tired of finish cracks around the holes. Now I'm trying out water base polyurethane finishes and can dry sand. I can see that thru string holes would be a problem, but I think Barry's suggestion of painting finish inside the holes with a small brush would work.

[Mario Proulx]

Try dripping some candle wax in them and see if that helps...

[Steve Sawyer]

Gordon - I figured the holes might need a little clean-out just to ensure the screws go in ok.

Peter - being my first build I wanted to dry-fit everything before I started finishing, so I could make any necessary corrections. Turned out to be a good move as I had to do a little work on the control-cavity, pickup and neck-pocket routes to get everything fitting properly. A Tele doesn't allow much room for error the way the pups, pick guard, bridge and control-cavity cover fit together like a puzzle!

[Steve Sawyer]

Sorry - meant to thank Mario/David for your suggestions. Those would probably work, but I'd be concerned with not getting those materials below the surface so they won't contaminate the sandpaper. I think a dollop of lacquer applied with a small artist brush, plus care to not let tons of water run down into the screw holes should do the trick.

[Andrew Mowry]

I sand just the areas around holes with "odorless" mineral spirits, and the rest of the instrument with water.

[Steve Sawyer]

I sand just the areas around holes with "odorless" mineral spirits, and the rest of the instrument with water.

\
That's not a bad idea, Andrew - thanks!

[Jason Rodgers]

Just picked this tip up from a friend: fill holes with a dollop of finishing paste wax.

[Paul Rhoney]

Get a can of paste finishing wax, there's a few brands that make it, Minwax and Trewax for example. Just fill the holes with that stuff after finishing, and it blocks the water from going in. When you're done, you can leave it in and it lubricates screws. Or in larger holes, or holes that you need to be open (like your ferrule and string-thru-body holes) you can wait for the wax to dry out (this happens fairly quickly, like overnight) and then blow the glob of the stuff out of the hole with compressed air. I'll do that, and I also seal most holes with thin CA before finishing.

[Jason Rodgers]

The aforementioned friend...

Get a can of paste finishing wax, there's a few brands that make it, Minwax and Trewax for example. Just fill the holes with that stuff after finishing, and it blocks the water from going in. When you're done, you can leave it in and it lubricates screws. Or in larger holes, or holes that you need to be open (like your ferrule and string-thru-body holes) you can wait for the wax to dry out (this happens fairly quickly, like overnight) and then blow the glob of the stuff out of the hole with compressed air. I'll do that, and I also seal most holes with thin CA before finishing.

[Steve Sawyer]

Paste wax - good suggestion!!