Acrylic Drilling.

[EdGallop41]

I've been turning close to 200 pens so far, all but 2 are wood. I bought two Tru Stone acrylic blanks for two specialty gift pens. The first split apart as the drill broke through the bottom. Lucky for me, I could still use the blank after trimming 3/4" end off. When I drilled the second blank I used a drill stop and was careful to stop just before breaking through and only trimmed off 1/4". I also noticed the difference in drilling wood in that it will get hotter so it took much longer (backing out to cool). No problem turning them and they polished up nicely. I'm hooked... I ordered the necessary resin and dye but need better molds than PVC pipe. I do not know how to mix the colors to get the thin lines like in the Matrix design. What is a good mold source for detailed color mixing?

 

[wyone]

I use an air hose and pretty much blow air continuously on the bit which both cleans out the shavings and also cools both the drill bit and the blank. I used to drill all the way through the blank when I first started, but now never drill through the whole blank.

 

[volozhin]

I also had a blowout with an acrylic blank. So I decided to let a blank soak in boiling hot water for quite a while this caused the acrylic to soften up and not be brittle. Never had a problem since.
Try it. It may work for you.

 

[KenV]

Really sharp bits help keep the heat down -- and with some care on the rate of feed, avoid damage drilling through. The technique to stop short and cut works with less than really sharp bits, and is safely conservative.

Casting --- that is a whole different learning curve -- have fun climbing the curve!!!

 

[Paul in OKC]

Using a waste board underneath the blank gives the drill something to go into as well, preventing blow outs.

 

[PAbernathy]

I use my lathe to drill all my blanks. I find that going slow and pulling back ever few seconds to clear out the cuttings helps. I was in a hurry (bad thing) one day on an Acrylic blank and I blew out the end....after than I used a slow and slower approach and at 700 RPM's seem to do the trick....have not had a blow out again since.

 

[EdGallop41]

Thanks to all. You were helpful.

 

[Tom T]

Yes I agree with Ken really sharp bits. Nice and slow backing out to clean out chips and keep the heat down. I drill all the way through with a backer board on my pen vice using the drill press. Never have a problem at all. Heat is a real bad thing. Also do not over tighten the pen vice or it will crush the blank when it is hollow and look like a blow out or split the blank. Slowest speed on the dril press also is good. I like the air idea also. Thought about a small Dan a few times.
I do not use a pen mill. I have had lots of issues of that blowing apart the blank or breaking the end off. I use a small delta disk sander keeping thing square with a PSI jig. It's just a peg on a plat for the brass tube to slid into. Then if I really am picky like usual I put the blank on a punch on the tail stock and put a sanding disk on the head stock with a pad with sand paper and gently sand the blank the last 32nd or 64th to make sure it is really square. On of the guys on the sight sells a really cool sand ping jig for the lathe. I really need to get one. Hope all this helps.

 

[EdGallop41]

I couldn't find the ping jig you refer to but will search again. I switched to a pen mill on my drill press but it is something else to keep sharp and a bit more time consuming than sanding if there isn't much wood to remove. I have had occasional wavy results, not sure why, with one acrylic end and not the other. I returned to the sander for most of the time. I do need to switch to carbide tools, especially if I can sharpen them.

 

[Fish30114]

Look on the vendor forums for the listings by Rick Herrell, he makes a nice rig that lets you use the whole surface on a sanding disc mounted in you headstock, you mount the jig in a drill chuck in your tailstock with the appropriate sized transfer punch to fit the inside of your brass tube lined blank, and it holds your turning perfectly square while offsetting it to use different spots of the sanding disc in your headstock. He also makes great tool rests and some other cool gear. Highly recommend him and his stuff.

 

[PapaTim]

I'm hooked... I ordered the necessary resin and dye but need better molds than PVC pipe. I do not know how to mix the colors to get the thin lines like in the Matrix design. What is a good mold source for detailed color mixing?

I don't cast blanks but I recommend you check out the IAP's blank making forum. The guys there could answer those questions.
http://www.penturners.org/forum/f178/