Drilling small hole in acrylic

[Alex]

So I bought a couple of float switches that I want to install in my sump. I've drilled plenty of large holes in glass but never a small hole in thin acrylic. The holes need to be 5/8ths. What do I need to drill the whole and is there a technique so I don't crack it?

 

[dannyp02908]

ill def say I have not done it, but a hole that small, I would just use a drill bit. go slow as to not melt the acrylic. Wen I drilled the hole for the float valve in my RoDi container, I used a drill bit.

 

[JohnK]

If you have access to a drill press, then clamp the acrylic down tight and drilling is effortless. Without a drill press, you can clamp the acrylic between two scraps of wood and drill straight through that and you should have no issues.
You just need to be careful that the drill doesn't bite into the material overly aggressively, causing it to bind up and either crack the acrylic or turn it into a spinning palm flesh cutter . As long as the material is clamped solidly in such a way that it can't get away from you you'll be fine.

Brad point drill bits seem to get along with acrylic better than regular bits.

 

[cilyjr]

Drilling thin acrylic can be tricky as it loves to crack. 5/8 is a pretty big hole so I'd consider a hole saw for that. Personally I use a standard wood bit when doing this. I'm sure a bunch of people will say don't but (and this is depending on thickness) because of the long pilot point it works well on plastic 3/8 thick and over.

They make a bit designed for this purpose with a pronounced V head and different edge that is supposed to reduce the chance of cracking (link below) I've not used it.

Regular bits (and the wood bit) can grab the plastic and spin the entire piece which can injure you so make sure it's securely clamped down. With a regular bit I might drill a small hole then keep making a bigger one until you are at 5/8. But that will take a while.


Acrylic bit

 

[Alex]

This is on a eshopps R-300 sump so I don't think I will be able to put it on a drill press even if I had access. I would have to drill it from the side. Would drilling closer to the seam reduce the chance of cracking? Should I still clamp wood on it?

Would this bit work or should I get a hole saw. If I go hole saw should I get diamond?

http://www.amazon.com/IRWIN-91140-8...7960778&sr=1-4&keywords=5+8+plastic+drill+bit


Starting to wonder if it is worth the risk. I wanted to put them in to have a high and low level warning from my APEX.

 

[JohnK]

I agree with Chris, use a hole saw if you can't clamp it down. If possible start the hole from both sides too, that will make it come out cleaner.

 

[Alex]

Should I use a diamond or a wood?

 

[cilyjr]

Wood. Diamond is only for glass

 

[cilyjr]

The drill bit you linked is not an acrylic bit. Use the hole saw and do it half way from each side.
How thick is the acrylic? 3/8 would be my guess

 

[Alex]

Would it still be helpful to clamp some wood on and would it be better to do it closer to the seam?


Is this my drill bit?

http://www.amazon.com/Starrett-AVH0...&qid=1457965265&sr=1-2&keywords=5+8++hole+saw

 

[this is me]

I drilled a couple of small holes(maybe 1/4") on the baffle of my sump so that the refugium can overflow lower to the return section. I used a regular drill bit.
I ended up cracking the baffle(not a big deal) on my last hole because I was getting too comfortable with the drill and went too fast. Go slow and you will be able to drill it.

 

[Alex]

Yes 3/8. Don't think I will be able to hit it from both sides because of the size of the return chamber.

Thank you for all the help.

 

[Alex]

Some one on reefcentral recommended a step bit. Has anyone used one for something like this?

 

[cilyjr]

Nope. It would probably work . The best bit does not curve slightly toward the cutting edge. Thats what can grab the plastic and crack it.

 

[HuuTa]

Step bit would work for it.Cheapest step bit is at Harbor freight

 

[Alex]

How about these guys

http://www.amazon.com/Neiko®-10193A..._1?s=industrial&ie=UTF8&qid=1457975312&sr=1-1

 

[JohnK]

Would it still be helpful to clamp some wood on and would it be better to do it closer to the seam?


Is this my drill bit?

http://www.amazon.com/Starrett-AVH0...&qid=1457965265&sr=1-2&keywords=5+8++hole+saw

I'd go with the hole saw you linked here ^

 

[cilyjr]

My issue with a step bit is how much space between the steps. If the acrylic is 3/8 but the bit is 1/4 between steps...

 

[Gsxkid]

Wood paddle bit all day long

 

[cilyjr]

Wood paddle bit all day long

This is what I meant by standard wood bit. Rereading my post I realized that wasn't clear. The long pilot point is helpful