How To Drill Acrylic And Other Brittle Plastics

A brief shop tip on how to drill clean holes in acrylic and other plastics.

[addisondavis]

Whew! Well done. So many 'how to' videos simply fill the air with unnecessary chatter. This was clean, straight and to the point. Proven by the "Because I'm tired of this demo" comment! Thank you!

[kenthowe]

Thank you! You helped save me $100. I broke a drawer on our new fridge. With your tips, I was able to drill holes and attach brackets to fix the drawer.

[qwypbth]

I followed his advice and it worked. No chips, no problems. Thanks YouTuber!

[FrederickTSchurgerDC]

The soap trick alone was worth the watch! Thank you!!!

[davidbray]

To drill acrylic without chipping and cracking, a twist drill needs to be sharpened with rake angle closer to zero so as to produce more of a scraping action, rather than cutting. By sharpening the drill bit the way you have, in effect achieves the same result, although I prefer to leave the conventional point angle on the drill and 'dub' the cutting edge. Either way works. The reason step drills are so good for acrylic is that by the nature of their design, they already have zero rake angle at the edges that do all the cutting. A similar principle applies to drilling brass.

[feriasexta]

I wanted to thank you for this video. I had a specialized piece of circular acrylic into which I had to drill three holes in order to secure it to a clock face. I was sweating bullets as in the past I tried (very unsuccessfully) to cut an acrylic sheet down to size for a different project. So brittle and finicky. I followed both your recommendations on shaping the drill bit tip, and using soap, and the drilled holes were absolutely perfect the first time. Thanks so much!

[moovintruespace]

Love the bit where you said you're tired of this demo! Thanks for your time. Great demo..

[MrRunner]

Having done this for years, I will share: A regular drill bit is fine, but it must be sharp and web thinned. If you don't know how to sharpen a drill, learn, or buy a jig. Next, do NOT use battery powered drills, they are too slow. Drill presses are best as they are stable and allow for clamping the workpiece firmly over a solid cutable substrate, like wood. If you don't have a press, use an corded electric drill. Example: to drill a 5mm hole in acrylic requires a speed of 2500 r/m, which a cord drill will do, whereas battery drills run at 1500 max. Next, it's the feed. Slow feed, clearing often. If you feed too fast, the acrylic will melt, if the drill is blunt it will melt, no matter what you do.
Hope this helps someone.

[dncook]

Thank you for the tips, never thought of using a sep drill for the holes I need to bore today or using soap.. great job.

[alienfunbug]

5 year old video and still useful as ever. Thank you!

[bernhard_derProtoTyp]

Oh! Great tips! I was aware that there are special acrylic drill bits that have a much higher point angle but never tried to sharpen one for that. And never ever would have thought that it is so easy. Super nice!!! Thanks again!
I had great luck with new, clean steel drillbits with slightly dull cutting flutes/tip (just a few strokes with a diamond file or 400grid sandpaper)

[makers_lab]

Perfect explanation, thanks. And that step drill is impressive, going through like it was butter.

[richarddoan]

Summary:
1. Sharpen drill bit to a point, or use step drills for larger holes.
2. Fully support the sheet with plywood backing. (You will drill through to the wood.)
3. Use low rpm.
4. Lubricate the bit with dish soap.

[jayc]

That was a wonderful demonstration! Crisp, and to the point. Thank you and best wishes.

[danerachaelgustafson]

Wish I had watched this video before breaking my $20 sheet of plexi-glass today ^_^ Thank you though, I am looking forward to getting this job done right with your help.

[brucecarsten]

I've found that even conventional drills work well to create smooth holes when lubricated (and cooled) with water and a little dish soap (say, 1% to 10%). I've even used this to drill very deep holes, 5 to 10 times the drill diameter, but you do need to keep backing the drill out to clear the chips, and do keep the hole flooded with the lubricant with a brush or squeeze bottle. As noted, slow speeds work best, but not TOO slow or the plastic can begin to fracture instead of cut. (I've modified my drill press to use a dc motor, with fixed voltage on the shunt field winding and a variable dc voltage on the armature for speed control, minimizing the need for pulley changes and allowing spindle speeds down to a few RPM. The armature supply also has an adjustable current limit, allowing the stall torque to be set independently, which I find handy at times to minimize damage to the work.)

[michaelcardona]

WOW, , fantastic short video; without all the high tech talk on how and why, your explanations and samples on the video are right to the point; i want to build a box for a project and I don't have the money to buy a piece 2 x 4 of PVC at Home Depot; my neighbor through out a piece of Plastic Acrylic and it was like my blessing until I realized it's brittle and will crack easily if you don't know how to handle it, YouTube and Vice Chief provided that bridge I needed to feel confident my project will be a success; I will come back & let you know how it went; Thank You Michael C.

[rodsnyder]

Thanks for the tip with the dish soap. Worked out for me very well.

[peterbarlow]

Step drills are great for all kinds of thin stock. They don’t get sucked in on break through like a fluted twist drill. Chose one with steps taller than the stock thickness or the holes will be stepped.

[cosmicbrambleclawv]

Very helpful! I had to modify my new name-badge for work to accept the old badge's clip thing, and this helped a lot. I didn't sharpen my bit any, but I did start my holes by drilling in reverse and then flicked it to forward and it came out clean as a whistle