Full Version: Drilling High-Gloss Plaque
From: Harvey only (HARVEY-ONLY) [#2]
21 Oct 2005
To: Engravin' Dave (DATAKES) [#1] 21 Oct 2005
For a nail hole, I mark the spot then take a .005 bit and with my hand spin it in that spot till I get through the epoxy coating. Stops the fracturing from the nail.
As far as drilling, never tried it but assume from the above experience that a standard drill bit with very little pressure would go through easily. If it grabs then use acrylic bits. I make my own bastard acrylic drill bits by taking a regular bit and flattening the cutting edge so instead of gouging into the acrylic, it has a 0* lead angle. (Cutting edge flat along the length of the bit.) Just a slight flat is needed to get rid of the very edge. Think of the leading edge of a half round engraving bit.
From: bobkat [#3]
23 Oct 2005
To: Harvey only (HARVEY-ONLY) [#2] 23 Oct 2005
From: gt350ed [#4]
23 Oct 2005
To: Engravin' Dave (DATAKES) [#1] 24 Oct 2005
David: I'm sure that you are aware that there are hi-speed steel and carbide bits for drilling thru metal, and there are woodworking drill bits for drilling holes in wood.
The wood drill bits are what you need. They have a brad point in the center and, as has been mentioned, the flutes are kind of cupped to provide a clean cut at the outside edge of the drill circle. Aside from using the proper bit, also using very light pressure should insure a clean cut.
From: Engravin' Dave (DATAKES) [#5]
24 Oct 2005
To: gt350ed [#4] 24 Oct 2005
Thank you all for the good info. I will try the woodworking bit. I hadn't tried one because I didn't have the size I needed. I will now. It does make sense that this would be a good solution.
Now, on to question #2. Working with the same type of plaque, have any of you tried using a 2" forstner bit to create a recess to insert a 2" medallion? I do this with pressed and solid wood to produce a higher quality look, but I have not attempted it with the piano-finished plaques.
EDITED: 24 Oct 2005 by DATAKES
From: logojohn [#6]
24 Oct 2005
To: Engravin' Dave (DATAKES) [#5] 24 Oct 2005
I used the rotary machine using a .25 parallel flx cutter (or the widest your cutter shank is). I am sure there are better cutter choices if you do it often but I just used what I already had.
I started with a circle and added hatch lines spaced just far enough apart to rout out the area. It is best to do the cleaning pass, the circle last.
You will have to use the manual depth set with serveral passes to get the depth as deep as you want. I left the depth nose attached to provide clip removal but it will not control the depth.
From: gt350ed [#7]
24 Oct 2005
To: Engravin' Dave (DATAKES) [#5] 24 Oct 2005
Although I have not used a Forstner specifically for a piano finish plaque, I'm sure it will work very well; particularly if set up in a drill press. And, frankly, it will be much quicker than a rotary engraver, and probably cleaner. Of course, this is as long as the diameter of the circle needed is covered by an available Forstner bit and the "brad" (as I recall) does not go further into the substrate than you have thickness for.
My second choice before resorting to a rotary cutter would be to laser the circle. Just mask and go. It will take multiple passes but, unless you are doing quite a lot, so what?
From: Engravin' Dave (DATAKES) [#8]
24 Oct 2005
To: gt350ed [#7] 24 Oct 2005
From: Shaddy [#9]
28 Oct 2005
To: Engravin' Dave (DATAKES) [#8] 28 Oct 2005
You might also cut a template from 1/4" MDF (or acrylic for that matter, whatever you have laying around) using your laser and use a router with a template-following bearing guide. Depending on your bit, you might have to stack a couple 1/4" sheets.
Might seem like a lot of work for cutting a circle, but I mention it here because doing things this way would open up some possibilites for doing other non standard shapes. Ellipse, round cornered rectangle...
Plus if you use the right bit (up or down spiral, depending on your use) you might have a good clean edge. A down spiral might keep the finish from fracturing or lifting up.
Shaddy
From: Michael [#10]
1 Nov 2005
To: Engravin' Dave (DATAKES) [#1] 1 Nov 2005
David,
You've been offered a lot of good advice, and here's one more suggestion:
Use a variable speed drill and drill at the lowest possible speed. Bit should be creeping. Very light pressure. As you pointed out, heat is the major culprit, and slow speed with light pressure will reduce that.