[SoccerMbunaAndShak]

I'm drilling a hole through some thin acrylic (it's the back panel of an acrylic 5 gallon bowfront tank) to put a 3/4 inch bulkhead in it. I don't have any scrap acrylic or MDF lying around to support the piece while I drill it to prevent cracking and chipping. Can I use 3 layers of cardboard between the acrylic and an old hard cover notebook. It will look like this

|
\_/ ] Drill bit
________________________________________________________________________________________________________________________________________ ] Acrylic
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww ] Cardboard
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww ] Cardboard
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww ] Cardboard
nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ] Notebook
nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ] Notebook
nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ] Notebook

I built this diagram and it seems pretty sturdy. I will be running it with water to keep things cool. Sorry about the ugly diagram.
Also, I am using a step drill bit. Is that ok? It said it was ok for plastics. However, it is a little dull. I tested it on an unsupported piece of hard plastic (the cover of an old fluval aquaclear filter) and it cracked at the 1 inch step.

 

[tacs]

I cannot speak at all to what you are trying to do with any authority whatsoever. Looking at it from just working with thin acrylic in other projects I would think that a hole saw would be a better way to go. My gut would try high rpm and slow going through. Let the the teeth eat away the plastic almost on its own. But I know not of what I speak. LOL.

I'm curious what the goal of the project is? Seriously, maybe you're up to something I would be interested in knowing about.

 

[SoccerMbunaAndShak]

Thanks tacs. I am trying to build a nano high tech planted tank. I had the 5 gallon lying around (it was my first aquarium). I did want to add water volume and a means of concealing all the equipment, so I'm building a sump, hence the bulkhead. Any help is greatly appreciated.

 

[SoccerMbunaAndShak]

Anyone else?

 

[tacs]

I've got nothing else but kinda hoped that jumping in would get the ball rolling. Sounds like a neat plan. Post up pics when you are done.

How thick is the acrylic? Perhaps there are other places to search for good information on drilling acrylic.

quick Duckduckgo search
https://www.wikihow.com/Drill-Plexiglass
https://www.ehow.com/how_5761248_drill- ... sheet.html

(warns about not going to fast - see shows what I know)

(old Joey video from the DIY King).

See if any of that helps you further down the road.

 

[SoccerMbunaAndShak]

I don't think the acrylic is more than 1/8 inch thick. Thanks for the links tacs. Will look into those for sure. I will probably post a thread once I get started on it. I have all the equipment in place, except for a few miscellaneous plumbing parts.