Different Drill Size For Sierra

[Michael67]

Hello Everyone, Who favors the use of a smaller drill size (smaller than 27/64") for the Sierra style pens? I have always used the 27/64", but at times encountered a "looser" fit on some blanks. I m guessing that is has been more of the acrylics then most of the wood blanks I have used. Also, I have tried different types of drill bits depending on what I'm drilling. All thoughts and comments gladly welcomed. Thx mike

 

[JimB]

I always think of the recommended drill bit size as just that, a recommendation. I haven't made a Sierra in a long time, years, but when I did I used a Z letter bit for wood.

 

[Scissortail Pens]

Michael, as Jim stated a Letter Z bit will do the job quite well. A 10.5mm will also do. Here's a link to a drill chart that may be able to help out a bit. It's a PDF file, but it's safe.

 

[rherrell]

27/64" is a good choice if you use epoxy, you need a little wiggle room with epoxy. I use CA to glue tubes so I also use a "Z" drill bit.

 

[Charlie_W]

My general rule for drilling is to drill 0.010" larger than the tube. I use epoxy to glue the tubes in.
If painting both the inside of the blank and the tube, you may need to allow a tad more for the paint....depending on paint type and application technique used.

 

[magpens]

I have used all three drill sizes mentioned: 27/64" (the largest), 10.5 mm, and Z (the smallest).

My choice depends on the material: 27/64" for "softer" woods, and Z for acrylic and hardwoods.

The 10.5 mm is only 0.0004" bigger than the Z so the two are essentially the same size.

The Z can give a fairly tight sliding fit with acrylics and hardwoods but is too tight for the softer woods which tend to contract the hole a little bit after the drilling operation.

I have pretty much settled into a routine of using 27/64" for all now because I use epoxy as glue and because many acrylics need internal painting of the hole due to the thin wall at the ends of the Sierra blank when turned to finished size.

 

[Michael67]

Thanks for the advice everyone. I mostly use CA glue for everything. Lately I have thought about switching to an epoxy for acrylic and some woods. Now I will look for an epoxy that works well and easy to use.