Drilling holes in Acrylic

[widdledink]

I am thinking about drilling a 1" hole in my acrylic sump so that I can place a bulkhead in for running my skimmer outside of the sump. Here is my question...has anyone drilled there own Bulkheads, and if so what kind of bit did you use.

I have been on a site that talks about building stuff with acrylic but doesn't mention what kind of drill bit one should use.

Secondly,
Has anyone usd a "door knob drill bit" on acrylic. (I am not sure what it is called but the large circular bits that are used to drill out hole for door knobs in wooden doors.) Seeing that I am going to be drilling a 1" hole for the Bulkhead it is cheaper to buy one of those instead of a 1" drill bit.

Thanks in advance,

Grady

 

[mogurnda]

The bits are called "hole saws," and they will work nicely for acrylic.

 

[widdledink]

they will work nicely for acrylic.

Have you used them B 4?

 

[OrionGirl]

I have. The main thing to is to use them on a slow setting so there isn't as much heat--otherwise, you get a bit of a burn to the acrylic, which stinks and can warp the shape of the hole.

 

[liquafaction]

What I do is drill a pilot hole first, usually 1/4", and use a dowel where your drill bit would be in your hole saw. This will keep your saw from drifting "out of round" from a regular twist bit heating up the acrylic. Also I would run your saw backwords when starting your "bigger" hole just enough to score the acrylic, This will keep your acrylic from chipping (from the saw grabbing too hard) on the first part of the cut.

Just to clarify, only run the saw backwords to score the acrylic. Do not try to run the saw backwords all the way through, or you will just burn a hole all the way through.

 

[RustyRay]

The roto-zip cutting tools are also good on cutting holes. "Forstner" drill bits also work well. Stay away from spade bits though.

 

[liquafaction]

Stay away from spade bits though.



LOL...... I would imagine that would rip a hole in it. Key word........R.I.P.

Out of lazyness, (to lazy to change blades) I used a ripping blade with positive rake on one small cut on some acrylic....... big mistake. A blade like that takes small shards out of acrylic.