Slightly scary prospect - enlarging pot holes in the top of a semi - what drill bit?

the_jaffa

I'm replacing all the electrics in my Epi Dot and have stumbled on yet another issue.  I was very close to getting it all back together and got to the point of putting the first of the pots back up and through the body when I discovered that the holes are too small.  The new pots have a larger shaft than the old ones.  Cue the removal (again) of the loom.

I know I probably ought to have checked before I got that far but hey.

Anyway, the upshot is that I need to enlarge the pot holes by about 1mm but also without going too far through and making some nice perforations in the back.

Would a stepped drill bit be a good option for this as it should self centre and they also tend to be short enough that it won't reach the back?  Most circa 10mm bits are pretty long and as I am likely to be doing this by hand I would need to make a way of preventing it from going too far through.

Any thoughts anyone?

TTony

Don't use power tools!!!

This is all you need;

£2.71

ThePrettyDamned

Reamer!

Edit: ttony beat me to it. Get one of those, go very slowly and gently. It's really easy, I've used one to enlarge the tuner holes on my guitar.

the_jaffa

Bloody hell, that's a much better idea.  Way safer.  Why didn't I think of that, cheers

That one up there looks a bit long and likely to bottom out on the back before it gets to the size required but I'll look for a quicker tapered one.

zenzeypher

I use a rat tail file, then a finer smaller file.. takes 2 mins a pot, looks fine.

GuitarMonkey

TTony said:

Don't use power tools!!!

This is all you need;

£2.71

For a semi? Are you going to drill holes so that the tip can come out of the other side? 

Just use a very sharp twist drill. Go very slowly (slow speed, little pressure) and cut (almost grind) through the finish carefully.

ThePrettyDamned

Those reamers

GuitarMonkey;187172" said:

TTony said:

Don't use power tools!!!

This is all you need;



£2.71





For a semi? Are you going to drill holes so that the tip can come out of the other side? 

Just use a very sharp twist drill. Go very slowly (slow speed, little pressure) and cut (almost grind) through the finish carefully.

Taper to 12mm fairly quickly, so I doubt it'd bottom out.

the_jaffa

I'm pretty certain that that reamer will be too long looking at the proportions of the taper.  It would also leave a tapered hole as I can't get at the back of the hole to even it up.  Totally makes sense for tuner holes but I'm not sure it'll work for this.  Will likely get on for the tool box though as it definitely looks like it could come in handy for other jobs.

As a development of zenzeypher's suggestion, I'm thinking I could maybe use a combo of round file and sand paper and just take some time.  I don't need to remove masses of material.

OilCityPickups

This is what I use ... and I've used it on some fairly thin semis
http://www.electricwingman.com/prop-reamer-4-step.aspx?gclid=CKO26t36lr0CFZShtAodx00A0g

I find it is a little shorter than a taper reamer ... plus is not tapered, so makes a less bodgy hole (especially for machine heads).

the_jaffa

That does look like a better option, cheers

I'm desperate to get to try your pickups Ash so keen to get this sorted but don't want to rush and wreck anything.

guitarcookie1

I used a round file when I had to do this to mine.

viz

Have you considered re-sourcing the pots and getting the thinner shaft ones? Surely that would be a tenner well spent?

GuitarMonkey

ThePrettyDamned said:

Those reamers ... taper to 12mm fairly quickly, so I doubt it'd bottom out.

I guarantee that it would!

ThePrettyDamned

GuitarMonkey;187295" said:

ThePrettyDamned said:

Those reamers ... taper to 12mm fairly quickly, so I doubt it'd bottom out.





I guarantee that it would!

My mate used my one on his epi dot and it worked a treat, but ymmv.

However, that stepped one is exactly what I needed for my tuner holes @theguitarweasel! I used a tapered one and it's not bodged, but I needed to use that then even it out with a straight 9.9mm reamer. A stepped one would have been perfect.

octatonic

I never use a tapered reamer as the cut is tapered, like the reamer.

This is the sort of thing where I might use a hand drill, as in a manual one:

http://system.buysend.com/Images/0/35195_1.jpg

Or a round file, or a stepped reamer as others have mentioned.

zenzeypher

A round file is easy, looks fine too... You'll wonder what all the fuss is about once you're done.

The woods pretty thin just put some tape over the holes and away you go

Unless you're super ham fisted it's hard to balls up

streethawk

viz said:

Have you considered re-sourcing the pots and getting the thinner shaft ones? Surely that would be a tenner well spent?

I would have thought this would be the path of least resistence. 

the_jaffa

Quick update - I popped out and bought some brand new HSS drill bits yesterday so had a nice sharp 10mm bit.  Used that and a cordless drill (but really carefully) and with a wooden spacer to prevent the drill going too far through and it worked a treat.  I did use some masking tape over the holes to help prevent the surface from chipping (which it did successfully).  It was all actually pretty easy in the end.

Thanks for all the advice everyone

I've now got all the electrics back in the guitar and it is all working a treat and sounds much better than before.

Very happy here!

usedtobe

I'm having one of those reamers!

WezV

zenzeypher said:

A round file is easy, looks fine too... You'll wonder what all the fuss is about once you're done.

The woods pretty thin just put some tape over the holes and away you go

Unless you're super ham fisted it's hard to balls up

it does depend on your file and technique.   too coarse a file and the veneer and paint can chip out

 

but yeah, a rat tail file or a reamer would be my choice.   failingt hat the real geurilla technique would be sandpaper around a pencil   I would not touch it with a drill