Simple Wood Working Question

[mustangcruise]

For my bass build, I'm ready to install the bridge. No big deal. It's properly located, and I have the correct dill bit for the pilot holes. Before drilling into the body, I have been drilling and tapping on body wood scraps to make sure I don't screw the actual body up. The issue I'm encountering is when I start tapping the hole with a screw, a small amount of wood around the hole starts raising up. The body's top layer is ziricote so it's fairly hard. I've tried different drill bit sizes, different lubricants on the screws and hole, different speeds when tapping the hole and nothing I have done so far will leave me a nice clean hole on the top. I'm more than likely over thinking this, but there must be a way to get a nice clean flat hole with the wood not puckering. Any advice you can offer is most appreciated.

 

[pcake]

can you plane the raised part off? that would be cleaner than sanding it.

 

[rudy4444]

Use a countersink to bevel the top edge of the hole. That will prevent deformation along the surface edge.

 

[T_Bone_TL]

Or counterbore just a little into the top with a bit large enough to pass the threads through the hole.

 

[Barticus]

Reverse the drill to break through the top layer to start the hole. Then drill.

 

[Matt Liebenau]

I use a countersink and chamfer the top of every hole in an instrument that’s going to get a screw in it. That eliminates the spot of grain pulling up as you start the screw. It doesn’t take much. Just a quick hit with the bit in the drill press.

Also, if it’s an option, I pick sheet metal screws in the correct size and usually stainless instead of wood screws. The thread is different and they seem to work better. Remember to lube the threads of whatever screw you use.

 

[Slidlow]

Use quality Brad point drill bits. Also chamfer the hole slightly so the screw does not push up any wood.

 

[Gilmourisgod]

Yep. Drill a small pilot hole and then use a countersink, even a cheap Harbor Freight one will work fine, and Bob's your Uncle.

 

[Rôckhewer]

I'm gonna go out on a limb & say your pilot hole is definitely too small if wood is raising up around the hole.
And, beeswax is your friend when driving a screw for the first time.

 

[mustangcruise]

Great and thank you for all of the advice!

 

[Kerplunk]

I know nothing about woodworking, so I don't know if this would work effectively or not. Put some masking or gaffer tape down and drill through that.

 

[Code Brown]

Put some masking or gaffer tape down and drill through that.

Tape can help reduce tear out when sawing, but it wouldn't help OP's issue.

 

[Kerplunk]

Thank you for your education CB.

 

[Jeff Hughes]

For some reason, I have found that priming the hole by going in reverse reduces the effect you are seeing.

 

[Jazzdogg]

Use an appropriately sized transfer punch to locate the drill bit on the work;

Know how to match the drill bit size to the root diameter of the screw;

Drill to final depth in steps, withdrawing the bit periodically to clear the flutes of wood chips before drilling further;

Use a sharp high quality Brad point bit;

Use a drill press if possible;

Set the drill's motor speed/rpm so it's correct for both the hole size and wood species to prevent burning.

Good luck!

 

[Plain Old Barry]

I’d simply zip the raised wood off with a sharp chisel.

 

[mustangcruise]

Before I forget, I need to thank all of you for the tips. The threaded holes came out better than expected.

 

[Dark Horse]

I’m sure somebody has mentioned it, but start by drilling your hole with the drill and reverse… Then once you have it started, you can flip it around forward.