I was thinking on this while making a PB&J and got to the bottom of to the peanut butter. I put the lid on the empty jar and put in aside on the counter but it tipped off into the sink and landed in a pan of water. It floated, of course, but because of where my mind was I saw a waterproof container, not just an empty jar. And yes a soft pack of cigarettes fit, I borrowed my son's cigarettes to check, with plenty of room for keys, cards cash - and a lighter.
Step 1: Getting Ready
*An empty peanut butter jar
*An old bike inner tube
*An old key ring
" Rough sand paper, 100 grit or so
" Mixing pad
" Mixing stick
Actually any jar will do for this project - just make sure it is plastic with a screw on lid. I used an 18oz jar.
Wash out the jar and take off the label. A little Goof Off, or some such product, will take off the old glue that held the label. Make sure to wash the underside of the lid.
Epoxy can be messy; I protect my work surface no matter if it is - kitchen table or work bench.
Have something disposable to mix the epoxy on, and something disposable to mix the epoxy.
Step 2: Inner Tube Gasket
2.Place the cut end on one side of the jar lid; it should over hang a 1/4".
3.Pintch the tube where it over hangs the other side of the lid, back off from the lid a 1/4" and cut the inner tube crosswise where you are pinching, eye balling it is just fine.
4.You should have an approximate 3 inches
5.Cut up the side of the tube and flatten out.
Step 3: Cutting the Gasket
2.Hold it in place and draw a circle around the lid.
3.Cut the circle out, but cut on the inside of the line.
4.Put the circle of inner tube inside the lid to see how it fits.
5.You will most likely have to trim a bit more, but keep it as tight to the edge as possible
Step 4: Prepare the Gasket
Rough up the underside of the lid with the sand paper.
Rough up the top of the lid, too. This will be needed latter, but might as well do it now.
Step 5: Attach the Gasket
1. Place equal amounts of the two parts on the disposable mixing pad. As you can see I used an old envelope.
2. Mix the two parts together well with the disposable mixing stick, in my case an emery board from a local realtor.
3. Spread the mixture all around the edge of the inner tube circle.
4. Carefully, insert into the underside of the lid.
I screwed the jar on to the lid just enough to keep the circle in place while it dries. Do not tighten down hard, this will squeeze the epoxy mixture thin and it may not get a good bond along the edge.
Step 6: Attach the Ring
1. Mix a small amount of epoxy.
2. Apply to the ring.
3. Hold in place until dry.
Really anything to which a length of rope can be attached will work.
You just need to be able to tie the jar to your river tube, kayak, or whatever so when it falls off it doesn't float away.
In the first waterproof jar I made I cut a half inch section off a cheap ball point pen tube and epoxied that to the top of the lid and attached a short lanyard.
Step 7: It Worked - Really Well
One of the unforeseen benefits of the height and shape of the 8 oz jar is the cigarette pack fits in in such a way that other things can be put around the pack the cigs can be got to without unloading.
I am not advocating smoking, but fascinated by the mechanics of this unexpected benefit.