@catgrrl@phendrick Maybe just missing some punctuation.
How To: You Using Your Soma Care Heat Pack.
How To: You Using Your Soma Care Heat Pack?
How To You! Using Your Soma Care Heat Pack.
How To: You Using? Your Soma Care Heat Pack.
How! To You, Using Your Soma Care Heat Pack.
@dam091 I have chronic back pain. They used a fancier TENS unit on it after the initial injury in physical therapy. I bought one of these last time I was on here and have used it several times. It works great, eliminating the pain for up to 24 hours after a 30 minute session. I usually use setting 1 at level 3 or 4. The only downside is if something happens to the contacts - I accidentally smushed one of the larger ones and now it doesn’t lay flat so I have to figure out to get replacements.
Search “replacement tens pads snap.” There are several places that sell snap on pads in several shapes. Amazon, Walmart, massage supplies. You can get 20-50 (reusable) pads for under $20, depending on where.
I don’t understand. Your local fire station isn’t going to just hand you these because you ask. They can’t. They have to buy their supplies, either with tax money or donations, and have to account for supplies used. EVERYTHING. Down to every gauze pad used on a call in most places.
@featherspy@xarophti lol, no we don’t. We throw away more supplies than you could ever imagine. I don’t know who told you that. You have any idea how much stuff we use on any given call? How much we use on training? How much we just waste? Everything has an expiration date too, and we toss it all when it expires.
Whether or not we would give them away, well that depends. If somebody asked me for a bag of dots nicely, I’d hand them over no problem. We currently have about 40 bags of them in our supply shed. Just ordered another case.
If you live in the Orlando area and need some, let me know.
I’ve got an ET tube sitting in my yeti right now. I use it as a straw.
I was being a little exaggerated, I admit, but inventory is still pretty strict some places. Especially when your local ambulance service has had someone jailed for cooking the books
Pain. Pain? You want pain? I’ll give you some pain 'cause, I’m gonna tell you how those heat pads work and what’s in 'em, besides.
[eye roll here for the technically challenged]
Phase change. See. Chemical phase change. You’ve seen it many times, like when water freezes into ice, that’s a phase change, when water boils into steam, that’s a phase change, when da moon hits your eye, like a big pizza pie, that’s an old song lyric. Get it?
Now get this, a phase change can be endothermic or exothermic. Meaning heat can be absorbed (endothermic) or released (exothermic). So in effect heat can be stored or released at will by means of a phase change.
The stuff inside those vinyl pouches is sodium acetate and water. A super saturated solution of sodium acetate in water at that. Meaning, that all the sodium acetate that can dissolve and a wee bit more has been dissolved. When you do that we call it a “super cooled solution” of the salt.
“So what’s sodium acetate,” you ask? It is the salt of the stuff that makes vinegar sour, namely, acetic acid. If pure acetic acid, called glacial acetic acid for reasons I shan’t go into here, is just reacted with just enough sodium hydroxide, aka lye, then the salt that is formed is sodium acetate.
OK? Got it?
Now here’s the neat part, a very pure super saturated solution, aka a super cooled solution, of sodium acetate is poured into a vinyl pouch and heat sealed. It will stay liquid indefinitely at ambient temperatures until something triggers nucleation.
Then, if liquid, when it is triggered by something such as one of those snap things put into the pouch just for that reason, the sodium acetate starts to crystallize from solution releasing the heat of fusion it took to make it liquid in the first place. And…and…and…the temperature of this process is automatically regulated to be 136.4°F (58°C).
For those for whom a hand waving explanation is not enough, here’s something to chew on that I found when I searched on-line. “Sodium acetate trihydrate (SAT), NaCH₃COO·3H₂O, consisting of 60.3% (weight percent) sodium acetate and 39.7% (weight percent) water, has the ability to supercool stable to ambient temperatures and has relatively high latent heat of fusion of 264 kJ/kg at the melting temperature of 58˚C (Zalba et al., 2003).”
By varying the amount of excess water in the pack, the maximum temperature can be controlled (reduced).
Once “frozen” or crystalized, putting it back into the liquid state is simple. Just put the pouch in a pot of boiling water, making sure that the vinyl doesn’t contact a too hot surface. Wrapping the pouch in a towel around the pouch before immersion is good practice to avoid this.
But, if the thing should rupture or otherwise break, no worries for the sodium acetate is relatively harmless, just being concentrated neutralized vinegar for the most part.
However, that being said, no one advises ingesting the stuff. Unlike say a telephone, which could be fatal if swallowed, this stuff is just likely to give you a bit of an upset tummy unless, of course, if you swallowed the vinyl bag too. Then all bets are off.
The genius of the whole thing goes to the guy who saw this latent heat of fusion or enthalpy change, and said, “Say, I could bag this and make millions!”
But the real genius or should I say geniuses were two guys named Joseph Stanley and Griffith L. Hoerner, who in 1976 came up with the metal strip clicker to initiate the crystallization and the release of heat at will. Otherwise, without it, you wouldn’t have a way of triggering the phase change.
@mehvid1@Skaene I have reset some small pads in the microwave as an experiment. Put one in a glass bowl, put enough water in it to cover the pad, washcloth or towel as a wet spacer on top (optional), and a small plate on top to keep everything underwater. Still a PITA, and I’d be worried that the little disc might eventually do something naughty to the vinyl or solution. Also, keeping a larger pad away from the sides of the glass bowl might be a challenge (wrap on all sides with a towel?). But on the 2 or 3 runs that I did with a 4" pad, I didn’t see any damage.
I thought of trying it with a sous vide circulator, but haven’t had the opportunity yet.
A sous vide circulator bath would be ideal. But you would have to get the water considerably hotter than 134° in order to put the precipitated sodium acetate back into solution in a reasonable amount of time.
No visible crystals can remain or when taken out of the batch, it will harden up again as the crystals present will act as nucelation sites.
I would say somewhere around 190°F should do it, but it is still going to take a while. If you were to do it over night just make sure that you have enough water in a large enough container to get the job done and not have the water bath go dry.
You could also try your dishwasher cycle using the hot cycle. If that works, then you could just throw the bags in the top rack along with dishes. Voilá, fresh, clean heating packs and clean dishes! Whadda deal!