Drilling acrylic-- Holesaw?

[minibowmatt]

I have to cut some holes in my new acrylic tank. I want to install 1" BH's. I have the 1/4" holesaw, but i was wondering what other techniques I can employ to ensure a clean cut? I think I may use a plummers putty dam with water to help keep it cool. how do you start a holesaw in acrylic? should I drill a pilot hole? Is there a better reef safe coolant/lubricant i can use instead of water?
Thanx!

 

[Anonymous]

This is how I drill acrylic up to 3/4 inch.

Get a hole saw with a drill bit in the center. I usually drill it dried, need to pull it out periodically (more like a few revolutions after more than 1/4 inch deep) to blow off the acrylic dust and clean the saw tooth to make sure there is no plastic gummed up on it.

When it is almost thru, be gentle on the last 1/8 inch if you want a nice clean cut. Oh, I usually use the slowest setting on the drill.

Some use water, but that usually make it more messy.

I would use a router for anything more than 1/2 inch thick, but you can use hole saw for pretty thick material.

 

[minibowmatt]

the tank is only 1/4" thick. Do you ever use a backer board to prevent chipping out as you pass through?

 

[Anonymous]

I have a couple of tips


If you can, after you drill part way through, switch to the other side and drill back. that way both sides are nice and clean.


Its not always possible to do that though, especially if you are drilling a tank that is already built.

clamping a piece of plywood to the acrylic will make for a nice cutout as the saw goes through. you need to use flat plywood, not that rough AC junk.

Its also helpful to drill a 1/4 inch hole first with a regular drill bit. especially if you are drilling with a hand drill. This makes it easier to control the holesaw as you approach the acrylic. a lot of people will be pressing too hard on the drill while drilling the pilot hole with the hole saw and when the drill bit goes through the holesaw slams down on the acrylic.


If you are have a scrap stick laying around as you pull the hole saw up to allow the chips out you can drag the stick against one side of the holesaw. that normally cleans the acrylic out of the teeth.



Hope that helps...

 

[Anonymous]

I usually do not use backing bpard, but that's because I don't ususlly mind if there is any minor chip. Buckhead's gasket should take care of it. However, going from the other side is a good trick, as well as the backing board. It just how cautious you are, FWIW.

 

[Rikko]

I agree with the others, and offer another tip:

Use a new holesaw, or a like-new one. If you holesaw is showing signs of being dull, you'll melt your way through instead of cutting (experience speaking here).

 

[minibowmatt]

I will be using a new holesaw. I think I might use the backer board, as I am a little over-cautious as this is my first bigger tank. Thanx guys! Now I just need my bulkheads to show up and I will be set.

 

[Anonymous]

Are you guys drilling with the holesaw using a drillpress, or will hand-held work for this?

 

[Anonymous]

Dan, you can drill a hole with a hand held drill just fine, you have to be more careful though, especially as you get up to larger sized holes and more powerful drills.

Up to about 2 inch is no problem at all, larger than that you want to make sure you have a good hold of the drill.

 

[Anonymous]

cordless drill with hand. Make sure you get an extra battery fully charged

 

[minibowmatt]

I used a drill press on my holes. Even with that it bit in a few times.

 

[Anonymous]

I have found that slow even pressure with a slight rocking back and forth motion to work the best when drilling with a hand drill.

I hate cordless drills, especially the more powerful ones, too much power for the kind of handle I think.

 

[Anonymous]

Never saw the cordless that could stand up to a Milwaulkee 1/2 in electric drill.

Good tips in there! I'm writing some down right now!

 

[jlneng]

Try using a Forstner bit...

 

[minibowmatt]

Forstner bits do work great on plastic. they do the "scraping" method of chip removal, which is preferred when working with plastic. They also seem to drill large holes cooler than hole saws.