Ranger band?

Large rubber band/section of inner-tube.

Also I have noticed your PSK thread now. Perhaps you are using a nicer looking but wrong construction tin. The genuine Altoids tin has special ridges/bulges on the lid and sides which are suppressing the pumping effect of the walls' play very well. Or maybe yours is just too large for its shape.

Ahhhh I see. Thanks

I have heard of those used on zippo lighters to keep the fuel from evaporating. I figure it would snap/rip before being able to be pulled around anything much larger. I have never tried it however.

Another thing I've noticed in that thread. The purpose of PSK is emergency only, not a backpack substitution. Everyday unwrapping, use, and wrapping back will ruin any makeshift seal quickly.

My tin PSK has recently made its way out from the "secret" blind sewn compartment of my tent's sack bag. It was sitting there untouched for 7 years. The ducttape sealed it so well that I had to cut it around the lid to open the tin. No wonder the content (fire starting and fishing) was in ideal shape.

All in all, my final conclusion would be: the Gorilla tape is not good for waterproof/airtight sealing.

I used what I had on hand, same as anyone. They are boker gift knife boxes and believe it or not they snap together real well. A good satisfying pop when the two halves connect. If nothing else I figured they were as good as anything else in the metal tin area of selection. I thought the tape would hold up. They will be used as fishing kits or something now. They still do have some utility to them, just not what I had intended. Always fun to experiment at the end of the day.

I would rather get outside and see firsthand what works and what don't than sit on the couch and speculate as many people I know do. They may still prove adequate for my mountain bike kit (should spend less time under water on my bike)

I wanted a general "one type fits all" PSK to be put in all my outdoor stuff (kayak, bike, hunting bag etc)

Maybe that was my first mistake...

Good click/snap/pop means only that the tin lip is fresh and that the metal is flexing well, the air gap is still there. Just try the real duct tape (thin, silver-grey one) next, don't cut it narrow. It's really working.

True. after being in the water with it I will always want to open it to check the contents however. Tape is just a PITA for that regardless, especially if using fresh tape to reseal the can each time.(fairly obvious that it would be looking back) Even now that I am switching to a Pelican case I will open and check the contents after going for a splash.

Live and learn they say.

My thoughts here, probably already said by everyone else...

1) You're right.
2) If you're sticking w/your Altoids tin use a lot of electrical tape.
3a) Strive to make everything in your PSK capable of enduring long term water exposure.
3b) I don't often carry a PSK. When I do it is in a round candy tin well electrical taped. A Pelican case or Otter box would provide more water protection (and I'm often on the water) but at the cost of substantially more bulk. Everything I do carry on me, which again usually does not include a PSK, I want to be able to tolerate what I can tolerate. With the exception of my cell phone I've completed this mission. My bic lighter, Skeletool, keys (including an ARC AAA), Surefire E1B, wallet, and lip balm have all been thoroughly soaked in saltwater and after a healthy rinse with some fresh water are no worse for wear.
4) Make sure you roll down the tops on those dry bags. Nice flat folds in the roll. If the bag says you need 3 folds make it 4 or 5. I've had great success with roll top bags but only when I do my part.
5) If you're storing things in waterproof containers for any length of time keep desiccant with said items to the extent feasible.

"Water proof" is different than "water resistant". Expecting tape to make something water proof is unrealistic. But it is perfectly reasonable to use tape to make something water resistant - as in you can carry it in the rain without much worry. For kayaking, yes, you would definitely want something water proof.

Where was that 3rd picture in your initial post in this thread taken? That looks like a really neat area!