How to keep finish from chipping from screw?

[jeffjozwiak]

I screwed in my bridge and the finish (Poly) chipped around the pilot hole. This isn't seen since under the bridge but I would like to prevent this from happening on the other times. What do you recommend? Countersink?

joz

 

[Watershed]

I ususally use a drill bit, roughly the diameter of the threads on the screw I plan to insert, to drill a very very shallow hole over the existing hole.  The goal is to only go through the paint.

James

 

[jeffjozwiak]

Yeah I think that is the way to go. I did this on the bridge hole after the fact. But the thing I did wrong was to hold it firmly in place. As soon as I started drilling it went right in. Not much resistance because I needed to apply pressure to hold it in place. The hole was a bit deeper than I wanted. This was with a long screw so it didn't matter. The other screws are for the strap holders and the plug socket which are much smaller and will require a delicate touch.

joz

 

[Watershed]

Yea, a drill press really helps.

 

[stubhead]

I also have an extra chuck - JUST a chuck - that I can put a drill bit or countersink in and twist it by hand. I love power tools -  :hello2: - but when you spend more time trying to figure out how to avoid ruining a $300 body with power tools than it would take to just DO IT BY HAND, well... hand tools ruin things slowly. You can twist a countersink with your bare fingers, crikey :toothy12:

 

[jeffjozwiak]

That looks perfect. I tried with my hands but didn't get far. I should pick up one of those hand chucks. Great idea. Thanks guys.

joz

 

[lern2swim]

Also, if you put some masking tape/painters' tape over the spot you're drilling it helps prevent paint chipping.

 

[burl]

i think you should put some tape used in painting  made of paper 

 

[Alfang]

I always use a dull bit for drilling through the paint, or, I spin the bit backwards,  It's the sharp edge of a new bit that grabs the paint and pulls it up that causes the problem.

Theres are some drill bits that have a small pilot bit in the center , and the outside diameter of the main bit is sharp and cuts straight down, I wish i knew the name of these bits as they are perfect for drilling into finished paint

I just found it, it's called a lip and spur bit http://www.axminster.co.uk/product-Axminster-TiN-Coated-Lip-and-Spur-Bits-19896.htm

 

[stubhead]

Or a "brad point" bit, Stew/Mac, LMII, a good hardware store's got 'em:

http://www.lmii.com/CartTwo/thirdproducts.asp?CategoryName=Rout%2FShape%2FDrill&NameProdHeader=Brad+Pointed+Twist+Drills

You still want to go slow with these, power drills need to be treated as "dangerous" around expensive finishes.