Wednesday, May 26, 2010

A de-galvanized rod

I looked in on my loggerhead after about 22 hours, and I found that the experiment with vinegar was a resounding success.  I now have a steel rod with about two inches of steel de-plated:

The zoomed-in section was fully submerged in the vinegar, and it appears to now be bare steel.  I had put some plastic wrap over the top of the bucket to try to contain the fumes a bit, and it appears that the fumes from the vinegar were quite corrosive to the zinc as well.  The metal is quite discolored for the whole length of the rod that was in the bucket; the shinier section toward the bottom of the picture is where the rod was above the plastic wrap, and it appears to be untarnished.

Next step:  a hacksaw to trim the rod down, a shallow, long pan, and a bunch more white vinegar.

Tuesday, May 25, 2010

New tool: the Loggerhead

OK, it's a 1/2" steel rod I picked up at Home Depot.  But I figure that once I heat it up and plunge it into a drink, it will be a loggerhead. 

I would have a new experiment tonight with my new tool, but as I was preparing for it, I took a glance at the pricetag attached to the rod, and noticed it said "Zinc Coated".  "Hmm," I thought to myself, "I wonder what temperature zinc melts at?"  Wikipedia told me it's around 787 deg. F, which is well within the temperature range I'm working in.  It also told me that zinc is relatively toxic when consumed in high dosages, and the fumes from heating it cause a non-fatal but unpleasant syndrome called "metal fume fever".


I could have gone over to the hardware store and gotten a new, un-galvanized steel rod, but where's the fun in that?  I seemed to remember from high school chemistry that zinc is fairly reactive, and a little googling found me a few forum posts on removing zinc plating from steel that recommended muriatic (hydrocholoric) acid.  I didn't have any of that around, but I did have some distilled vingear (~5% acetic acid solution).  So, I roughed up the end of the rod with a file (more surface area), threw a couple of inches of vinegar in a plastic bucket, and let the rod sit for an hour.  Sure enough, when I checked back, there was a little film of bubbles collected around where the rod met the vingear, and the roughed-up sections were starting to change their appearance a bit.  The bubbles are hydrogen gas. I took a long match and tried to light them for fun, but I guess there just wasn't enough compared to the amount of liquid around them, and the match went out with little fanfare.

I'm going to leave the rod in the vinegar overnight and see how it looks.  I'll also have to either buy a lot more vingear, or find a taller, narrower (or wider, flatter) vessel to hold the rod under the liquid and strip off more of the zinc.

Tuesday, April 13, 2010

Experiment 1: Heating the Poker

While I eventually plan to purchase or make equipment specifically for these experiments, for now, I'm working with what I have around the house. Here's the kit I used for my first experiment:

The bucket holds 5 G and is more or less 4G full. The blowtorch is a standard propane torch. The sword is made of steel, I believe, is unsharpened, and is something I picked up at a garage sale. Attached to the bucket is an oven thermometer that turned out to be useless; I also had a digital thermometer.  The fire extinguisher was fortunately unnecessary.
My first experiment was to figure out how I could heat a poker to red hot, enough to get some real steam and flame from a drink.  I tried a couple methods, and quenched the "poker" in the bucket after each attempt.

Part 1: Heating the flat of the blade with the blowtorch.

I rested the blowtorch on the ground and put the wide part of the blade, just behind the tip, in the flame. I held on to the blade near the hilt, ready to stop if I felt it getting warm at all, but the temperature of the blade in my hand never changed. After about 2 minutes, the blade started to glow dull red where it was being heated.  I quenched it in the bucket, raising the water's temperature from 61.5 F to 62.0 F.  The water boiled around the blade for a second, but it was quickly cooled down to water temperature.

Part 2: Heating the tip in with the blowtorch

For my second attempt, I tried heating just the tip, to see how quickly I could heat it.  It was cherry-red after about 1.5 minutes, as you can almost see in the pictures below.

When I quenched it, it barely sizzled, significantly less boiling than the first attempt.

Part 3: Heating the tip on the stovetop

For my third attempt, I placed about 3 inches of the blade in the flame from the burner of my gas stove.  The tip glowed cherry-red after about 2.5 minutes, although it faded quickly when I shifted it slightly.  After 4 minutes, I took it off the stove and quenched it.  The boiling was much more dramatic, as the blade had obviously stored quite a bit more heat than in the previous two attempts.  I believe this is because much more of the blade was directly in the fire than when I used the blowtorch, and it stayed there much longer.  After I quenched it, I ran water down the blade to check its temperature, and it was hot enough to quickly make the water steam visibly as far as 6" above the tip.

Conclusions and future investigations
  • A blowtorch heats the steel more quickly than the stove, but the stove is able to transfer more heat energy to the blade, most likely because of the size of the heated area. 
  • It's safe to handle the end of the blade with my bare hands, although maneuvering the hot, long blade around can be a little tricky, and I'd be worried about trying to get it into a tall glass without hitting the side or spilling the drink. 
  • Steel heated for short periods of time raised about 4G of water 0.5 deg F (although I didn't control for the heating due to the warmer room air).  The numbers are very rough, but the same amount of energy raises 4oz of water 64 deg F, which is in the ballpark for making a warm drink.
  • I'd like to get a piece of rebar or other iron or steel rod, which would be thicker in cross section.  It should hold more heat, although be proportionally slower to heat up.
  • I'd also like to pick up an infrared thermometer, to take readings of how hot the steel is.
  • I also need to investigate holding the steel so that the long axis aligns with the flame of the blowtorch, so more of the steel is exposed to the flame.

Monday, April 12, 2010


I'll post the results of my initial experiments shortly. For now, take a look at the Inspiration and Mission section.