How to Build a Hot-Knife Bong

I like hot-knives, they are my favorite way of consuming a certain green, questionable substance. hot-knives are super efficient and they definitely get the job done. That said, a lot of people find them to be very harsh. The hot-knife bong is my way of getting around that particular problem.
In the past I've used several different designs, but this one seems to work the best over all.

Step 1: Stuff You Will Need

To build one of these you will need these supplies, or some variant of them.

-a length of wire, I used 14gauge fence wire, but a coat hanger should work just as well.
-A jar with a thick, air tight lid. this one has a cork in it, in the past I've had success with plugs made from Sculpy as well.
-about 4 or 5 feet of surgical tubing.
-4 to 6 inches of 1/4 inch vinyl tubing or equivalent.
-a drill and 3/8" drill bit
-3/8" tubing, i use refill tubes from the plumbing section of the hardware store.
-a hacksaw

Not pictured
-a glass bowl (preferably with a short stem)
-dish detergent
That's it.

Step 2: Plumbing the Device

Lets start with plumbing this device shall we.

Firstly, drill a pair of 3/8" holes in the lid. Next slide the refill tube through one of the holes to figure out how long you need it. it should be about 1/2" off the bottom of the jar and have about an inch sticking out the top. mark your length and cut the pipe with the hacksaw. measure and cut a second piece that sticks out just a little from the bottom of the lid and has about 1" poking out the top.
slide them into place, friction should be good enough to hold them there and be mostly air tight.

My hacksaw made a mess of the cuts, leaving lots of burrs and deforming the pipe itself. I haven't had this problem before, but i solved it by using some needle nose bring the pipe back to round and then taking the burrs off with a file. all told it took about 10 minutes. I think the problem was that my hacksaw blade had too few teeth per inch.

Step 3: Adding the Hoses.

You'll need 2 hoses for this. I'm using a 1' hose for the bowl and a 3' hose for the mouthpiece.
Start by cutting your hose to the right lengths, then smear a dab of dish detergent around the tops of the tubes. with the dish soap on there you should be able to easily slip the surgical hose over the tubes. it's as simple as that. once your done you should have a long length of hose coming off the short tube and a short hose coming off the long tube.

Step 4: Adding the Bowl and Mouthpiece.

To start with we have to give the bowl hose a bit of substance. to do that We'll need a length of wire a little shorter than the hose and tube. Take on end of the wire and add a few squiggly bends to it. the idea is to make that end sit tight in the tube. Now just feed it up from the bottom of the tube, making sure the bent end winds up in the bottom of the tube.
Now that your bowl hose has a bit of backbone to it it's time to add the bowl. to do this simply add some dish soap and slide it into the hose. make sure the end of the wire ends up in the stem of the bowl but not sticking out of the bowl itself. now just bend the bowl hose into a convenient position to serve to. I also like to add a bit of tube into the end of the other hose to use as a mouth piece.
For the mouthpiece on this one i used a 4 inch or so length of 1/4" black vinyl tubing and slipped it into place with some more dish soap.

Step 5: Finishing Touches.

Now your all ready to test the seals.
I had issues with the holes for the tubes. instead of leaving nice round holes when i drilled them the cork chipped and flaked away around the edges, making for a fit that although tight, wasn't very air tight. I solved this by adding some waterproof wood glue around the edges of the tubes and working it down into the holes themselves.

Once your seals are good you may decide to beautify your bong. In the past I've wrapped coiled wire "springs" around the hoses, made leather wraps similar to hookah hoses, and used cloth covers. my favorite is the leather wrapped, but the cloth covers are the easiest.
you may also opt to paint or stain wooden plugs. If you used Sculpy then your imagination is pretty much the limit there.

Another common extra is a shotgun or choke. that can be as simple as just drilling another hole in the plug, I recommend adding a third tube to this hole that comes down to 3/4 of an inch or so ABOVE the water line. you could even go as fancy as using 2 tubes of different diameters with a cap and a ball bearing to make one with a built in valve. usually though i just make some kind of a cap from Sculpy or carve down a put of wood into a plug for the shotgun.

My digital camera drowned on the West Coast Trail. I was planing on adding pics of a cloth covered hose, a hookah style, spring wrapped hose, and one with a shotgun, but that will have to wait till I get a new camera.