Drilling Acrylic

[jef4y]

Looking for experienced advice in drilling acrylic for bulkheads.

Wondering if I should pull the center bit from the holesaw or if it is okay to leave? I'm worried about the center bit grabbing and cracking the pane.

It's 3/8" or 1/2" (I forget) thick if that matters.

Thoughts?

Thanks in advance.

 

[eagle9252]

what i like to do is pull the outside hole saw off first then drill the 1/4" pilot hole then the outer. my reason is when you drill the 1/4" hole some times when it goes through the hole saw wants to grab and twist. sometimes it breaks the drill bit and sometimes it will twist the drill out of your hand.

 

[jeep9783]

I leave the guide bit on mark your spot and go for it. Very easy to drill acyrlic just make sure you go slow so it cuts instead of going fast and burning a hole in it.

Chris

Also make sure bit is fine tooth for a cleaner cut.

 

[grouper therapy]

Set the clutch on the drill so that it will slip and not bind the bit.

 

[jef4y]

grouper therapy;776257 wrote: Set the clutch on the drill so that it will slip and not bind the bit.

Brilliant idea. Thanks!

Thanks everyone for the input.

 

[acroholic]

I've used standard hole saws for sump bulks, and I leave the center bit in there, because if you don't the hole saw can dance on the acrylic. Never had it crack the plexi.

What I do is use a slow rpm on the drill to keep the heat down. Let the bit cut the plexi while applying minimal pressure on the bit itself. Drill about halfway or more through the acrylic from one side until you are not completely through the acrylic with the hole saw, but have gone through with the center bit. Then, drill from the other side using the center bit hole as a guide. You get a nice clean hole with no burrs on it vs drilling completely from one side. Always rough on the side the hole saw breaks through.

 

[jef4y]

Acroholic;776287 wrote: I've used standard hole saws for sump bulks, and I leave the center bit in there, because if you don't the hole saw can dance on the acrylic. Never had it crack the plexi.

What I do is use a slow rpm on the drill to keep the heat down. Let the bit cut the plexi while applying minimal pressure on the bit itself. Drill about halfway or more through the acrylic from one side until you are not completely through the acrylic with the hole saw, but have gone through with the center bit. Then, drill from the other side using the center bit hole as a guide. You get a nice clean hole with no burrs on it vs drilling completely from one side. Always rough on the side the hole saw breaks through.

Can't do that. Not enough clearance. Drilling into an overflow already built and into the return chamber of my sump, but I get what you're saying and think if I keep the pressure to an absolute minimum I should do fine and have a clean cut.

 

[acroholic]

JeF4y;776290 wrote: Can't do that. Not enough clearance. Drilling into an overflow already built and into the return chamber of my sump, but I get what you're saying and think if I keep the pressure to an absolute minimum I should do fine and have a clean cut.

I get you. My hole drilling was on new, empty sumps. You should be fine.

 

[tony_caliente]

Otherwise the acrylic will melt and burn.

JeF4y;776261 wrote: Brilliant idea. Thanks!

Thanks everyone for the input.

 

[morganatlanta]

I pre-drill a piece of plywood and clamp it on to help as a guide, which keeps the bit from wandering. I also usually clamp a piece of wood on the inside too, which keeps the bit from cracking the last fraction of a mm before pushing through.