[NewCandle] Mega-roll goes critical

[Nick Reiter]

Hi Keith,

Well, the basic version that is on the table here
contains the following specific elements:

* rolls of aluminum kitchen foil (the thin cheap
stuff) that are hacksawed in half, with the inner
remaining cardboard tube scrunched and pulled/twisted
out.  Sam uses 200 foot size rolls of Kroger brand
foil.

* PETE Kroger "Snap-Lock" plastic storage containers
for the reaction vessel (has a nice inner rubber lid
seal).  The one Sam used and the size that he sent me
is the "half gallon" sized version.

* an aqueous solution of ~ 2 tbsp. of Morton table
salt in distilled water.

Now, the versions I had tried a while back that just
sorta sat there differed in the following ways:

1.  I used a little less than a half (sawed) of a much
smaller roll of foil (a "75 foot" roll, not Kroger
brand).  Just used the single ~half roll section. 
Thus about 30 square feet of foil surface rolled up
instead of 400...

2.  I used a smaller snaplock PETE container (the one
quart size).

3.  I have a feeling I handled the foil roll a lot
less than Sam did, since he used a manual hacksaw at
home, and I sliced mine zip zip on a bandsaw at the
lab.  I don't know how much of a factor skin oils
might play, but its a minor variable I can't quite
dispense with.

Thats about it.  When I tried this twice, with the
salt water, the rolls never really took off on their
own.  On the one occasion, I added a little pinch of
NaOH to try to "trigger" things, and I got a little
bubbling for a couple of days before it went dormant.

I am inclined to try a version later this week with a
"split the difference" arrangement - maybe use two
half rolls of the "200 foot" stuff instead of four. 
And keep it out on in the back 40 on a cement slab...
with a couple of TCs attached.

Best of luck to any who want to give this a whirl...

N


> So now that you have a protocol that works, what
> were you doing before that wasn't? I'll try
> something
> here but I don't want to do a large device for
> safety reasons and if I understand you, smaller ones
> weren't working... What I'm sorely tempted to try
> now is a small one with a heater. I think that's
> part of the magic, the large thermal mass allowing
> a buildup of heat and the reaction hastens.
> Alternately
> I could do a cell in a dewar, to trap the heat and
> simulate a big cell.
> 
> K.
> 
> 



       
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