Cutting the bottom off of a Better Bottle

Systems, Gear, & DIY
1

I want to use an old Better Bottle carboy for a hopper on my new JSP grain mill.  Has anyone had any luck or have any advice on this?

Honestly at this point I think I’d shred it if I tried cutting it with anything I have.  My best guess is to use a torch to cut the bottom off.

2

My first thought is a dremel. Wrap a length of masking tape along where you want to cut and use a cutting disk. I’m sure a few passes with a very sharp razor blade would do fine as well

3

+1 on using a small thin cutting wheel. Knives or reciprocating will likely not work well. I did a bunch of plastic cutting when I built that greenhouse. Its easy to shatter

4

A dremel might work, but I think a coping saw with a fine-toothed blade might be your best bet. Something like you’d get at an art supply store for cutting foam.

5

I’ve never done this, but in principle some NiChrome wire, DC transformer, good ventilation and spare hardware to hold everything snug should melt right through the plastic and leave a relatively smooth edge.

6

+1 to the Dremel tool.  I’ve used one with a thin cutting wheel many times to cut plastic.  Works great.

7

I also vote Dremel. They make a plastic cutting accessories so if you are willing to drop a couple of bucks you can have a purpose built plastic cutter on hand for years to come. The one I have is a metal wheel with teeth around the wheel. Cuts smooth and fast.

8

Thanks to everyone.  I think I’ll give the dremel tool a shot.  Now I just need to find out who I lent mine to.

9

If you have a harbor freight nearby. http://m.harborfreight.com/80-piece-rotary-tool-kit-97626.html

Low quality, but it’s done a few jobs for me.

10

I used a coping saw

11

How did it work?

12

Easy. I filed down the edge a bit

13

Well good!  If I can’t find who has my dremel, a coping saw is cheaper.

14

I do like the nichrome method. But then again, any method having to do with melting, exploding or burning is always preferred.

15

Do you have a table saw?  Just set the blade to 1/16" depth and rotate the bottom of the BB against the guide.

16

If there’s nothing wrong with the carboy, I would save that puppy and buy a 5+ gallon jug of water from BJ’s.  The deposit is only $5, and they have a 5.25 gallon capacity.  I did this exact same thing for my old PhilMill.

17

I’ve got two that I never use anymore since I have a conical and a Speidel… and only one fermentation chamber.  So $5 would be a waste IMO.  I figure I’ve got two chances to get this project right.

18

I would just use a firm karate chop.

19

Wear goggles

20

I couldn’t locate my Dremel nor any NiChrome wire (which would have been cool).  So I went with the coping saw.  It did produce a slightly rough edge but nothing that would be an issue so I am not going to take the time to clean it up.

Here it is all assembled.  The connecting piece is a short section of the female end of a 2" PVC pipe.  The bottle fits in the female end and about an inch and a half of the normal diameter of the pipe fits well, though not snugly, in the hole of the ‘Large Hopper Adapter’ board.

Goggles will only be required after drinking a bunch of the beer this will help produce.