Enlarging an already-drilled hole???

[luv951]

How can I enlarge a hole that is already drilled in a glass tank?

I only need it to be a very small amount larger, less than 1/16 of an inch across it's diameter.

 

[Pbrown3701]

a dremmel and a diamond bit will do it. Use water to keep the bit cool

 

[luv951]

Is a rotozip as good as a dremel for this type of thing? I have one of those, would hate to buy a dremmel just for this.

 

[RussM]

A rotozip is really just a Dremel-type tool "on steroids". Keep the tool speed low, cool/lube with water, and it should be fine.

 

[luv951]

I thought a rotozip was slower than a dremmel. I have never owned a dremmel, but I thought the spun at like 90,000 rpm. I have no idea of any torque diferences.

Is there anything like a wood rasp (but, obviously not wood rasp) that would work and can be used by hand to do this?

 

[stugray]

You can get diamond carbide "sanding drums" at Harbor freight for a couple of bucks.

Stu

 

[luv951]

Dude, thanks!

 

[kgross]

Make sure the glass is not tempered before you start grinding though.

As long as it is not tempered it is very easy to do. If you have a harbor freight locally, get the diamond sanding drum it is a lot easier to keep the hole circular, than it is with the tile bit on the rotozip.

Kim

 

[luv951]

yah, I figured the tank was not tempered as the previous owner used a dremmel and a diamond bit. The holes were "choppy" circles.

I got the bits from Harbor Freight - $5.00 for five different shapes. They worked awesome. I had five holes to enlarge and it took my maybe 45 minutes to do all of them.

Thanks to all who helped - you made this easy!

 

[luv951]

By the way.

My experience was that it worked MUCH better without water. The water seemed to slow the process drastically. Without water, I still would take the bit off the glass every minute or two and give it a quick spray with water to cool it. What was left on the bit quickly evaporated or turned to paste as the glass powder mixed with it.

Just my experience. I was not sure if water was needed or not when I started. I figured better safe than sorry, but as I got going it seemed to go much faster without water.

Take it for what its worth.

 

[noahm]

If you've ever seen a tank panel go from whole to a 'whole lotta pieces' in a 1/10th of a second, you will appreciate the cooling effects of water and deal with the slow pace.

noah

 

[Pbrown3701]

yeah, not using water is quite risky. It may go slower, but the cooling is to prevent the glass from shattering due to the heat.

 

[luv951]

I never went full dry. I also stopped every now and again and would spray the bit down to cool it, and mist the hole as well.

Either way, point taken. Just glad the worst did not happen!