Reservoir Body Thickness

Tue Nov 27, 2018 1:01 pm

Since we started the handwarmer project a few years ago, we're getting enough feedback now that the most problematic handwarmer to rebuild and get good results from are the standard Zippo. It's a perplexing problem because the same materials we get great results from in other models, do not perform as well when used in the Zippo. Today I put my collection of handwarmers together for a group shot:
Reservoir Body Thickness Thickness1

I noticed that the Zippo (on the far left below), was the thinnest of them all:
Reservoir Body Thickness Thickness2

So this made me wonder of the effect of the thinner body means the reservoir of the Zippo does not have as much thermal mass, and cools down much faster and easier (read about the effects of 'cold shock' on our Website:

Like your first romance, another factor that can halt your catalyst is a sudden cold insult, however this time it will have been convective, radiative , or conductive in nature. Setting the hand warmer onto something that is so cold it sucks the heat out of it, or subjecting it to a very cold wind are just a couple of examples of events that might shut it down because it lowers the temperature below that which can support the continuation of the exothermic process. When this occurs, you will probably find it very difficult to get it going again by directly heating the immediate vicinity of the catalyst head as outlined above because the body of the hand warmer is so cold there is no more vaporisation of the fuel. To get it going again, first caress the shoulders of the reservoir half of the case on both sides below the catalyst with the tongue of your lighter (this is where the turbo flame comes in handy). This fulfills two goals: it starts the fuel in the reservoir vaporizing and moving into the head again, and it heats the skeleton of the head which in turn supports resumption of the catalysis. After you have heated the shoulders of the reservoir, it should be easy to get the catalyst activated again with a quick application of your lighter flame.

If this indeed is one of the problems inherent to the design of the Zippo, then it underscores the importance of pre-heating your Zippo before you activate the catalyst, keeping it warm, and not 'cold shocking' it.