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5-Minute Sieve

August 20, 2010 Leave a comment

I was blending aluminum siding and I needed a way to separate the sizes and keep the finest dust out of the blender and my lungs. It doesn’t look pretty but a sieve made out of door screening fitted between two yogurt containers does the trick.

1. I first cut the bottom off of one of them and traced a circle on a square of screening with it. I then cut the screening into a circle about an inch wider than the circle that I traced and then cut tabs that I folded around the outside of the yogurt container and taped down.

2. To get the two containers to fit together tighter I folded a sheet of paper into a strip and taped it to the outside of the top container.

3. To use my sieve I stack the two containers, put my material of mixed sizes into the top container, put the lid on and shake. The finer powder falls to the bottom container while the un-blended stock remains in the top.

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Lab Storage Space

July 22, 2010 5 comments

 Stuck for space? Try this.

Until I get my garage cleaned out, there is very little space for storing my chemicals and lab equipiment. Since our microwave died last year, it has become the main storage area for all of my chemicals.

Categories: Random Tags: , ,

700 Match Heads

Yesterday during spring/summer cleaning I found 35 match books. Having nothing better to do, I burned them.

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Discount Glassware

I recently purchased a lab’s worth of glassware from Ginsberg Scientific on Amazon for about $70. The individual pieces are as follows: Griffin beakers, one 50ml, two 250ml and one 600ml — Erlenmeyer flasks; one 50ml, two 250ml and one 500ml –six medicine droppers — six stir rods 6″ — one graduated cylinder 10ml — one graduated cylinder 100ml — one serological pipet — twelve test tubes 16x150mm — one short stem funnel 75mm x 75mm. All (with the possible exception of the eyedroppers) are of Bomex borosilicate glass and are resistant to thermal shock. I hope to be using these soon.

How to Make a Power Supply

Power is needed for many processes and reactions, but DC current at the right voltage can be hard to come by. If you have an arc welder or a car charger then that’s great, but if not then you can just convert a computer power supply.

Materials

Computer power supply, multimeter, binding posts, soldering gun, solder

1. First, find a computer power supply (technically modifying and not making). You can get this from any old computer, some might be better than others; but I wouldn’t count on it. I would check the dump, but you could also look on Craigslist and eBay. The binding posts are not strictly necessary, but they make it neater and only cost a couple dollars at Radio Shack.

2. Crack it open with a screwdriver to reveal the wires. Cut off the plugs and wire ties (making sure to leave the power to the fan).

3. Drill holes into the side of the supply and attach the binding posts. It’s a good idea to label the voltages of each binding post.

4. Sort the wires by color. The different colors for mine are: black-ground, orange-3.3V 17A, red-5V 22A, blue-5V 22A, White- 12V 18A, yellow-12V 18A, brown-sense wire, green-DC on (for adding a switch), grey-power on (for adding an on-off LED. I only used the orange, red, and white wires because the yellow and blue wires have the same voltages and I saw no point in adding a switch or indicator light. In my power supply there were different shades of blue and orange but a test with a voltmeter revealed that the voltages were the same. If you can find wires with opposite voltage (+/-) then be sure to use them, as they will double the voltage between them.

5. Tape the wires together by color, cut all of the ends to the same length, strip the last inch or so, and solder them to the binding posts. It may be helpful to leave a single wire longer, solder all of the other wires to it, and solder it to the binding post. Make sure that you solder the brown sense wire to the 3.3V orange wires or else the power supply will not run.

6. Tape off all exposed wires, reassemble it, and find a use for your converted DC power supply. Make sure not to short out the wires because that will trip an internal safety and it won’t work for several minutes.

If you want to add a power switch or indicator LED then take a look at this.

Car Battery Salvage

As a follow up to my Lantern Battery Salvage, I thought I’d do an article on car batteries and the useful things that can be found in them. Car batteries are a little hard to come by; I got mine from a lawn mower that was being scrapped, but you could also check your local dump for one. Keep your eyes open though, because they can be almost as useful in pieces as they are whole. From a good battery you can get lead, lead dioxide, and sulfuric acid. Each of these is useful in some way.

1. The first thing I did was charge the battery to its full capacity, as a dead battery contains no sulfuric acid, lead, or lead dioxide, only lead sulfate. Old batteries should be avoided too, for the reason that as they get older less and less of the lead sulfate converts back into its components.

2.Once it was charged I drilled a hole into the base of each cell and drained the sulfuric acid into a glass jar. I dripped a little onto the wooden deck I was working on which didn’t worry me until I noticed that the screws were fizzing. After washing it off with baking soda water there was a white mark where the acid had bleached it back to it’s original color. I decided it might be a good idea to continue on the gravel driveway.

3.  Next, I used a Dremel Tool to cut off the top and reveal the plates. If the battery is charged then the positive terminal is connected to lead dioxide and the negative terminal to lead. In my battery the lead dioxide was a powder pressed onto a grid and the lead was in a plastic bag. If the battery is uncharged then all of the plates will be lead sulfate.

4. It took about an hour to pull the plates out and separate the chemicals from the battery. I didn’t use gloves for this because my leather gloves tore open, and the acid stung like hell and stained my fingers for a couple days.

5. To purify the sulfuric acid I let the lead settle and filtered it. I will probably boil it later to concentrate it.

So to sum up, I got two jars of sulfuric acid, lead, and lead dioxide, all of dubious purity. I had planned of making a lead dioxide anode but electroplating is more trouble than it’s worth and the other method I’d heard of – mixing lead dioxide with epoxy- gives too much resistance to be viable.

Just as a demonstration of the sulfuric acid, these are the gloves and pants that I was wearing during all of this.

Categories: Chemicals, Chemistry

Lantern Battery Salvage

March 25, 2010 2 comments

The other day I found a six-volt lantern battery and decided to see what I could salvage from it. After doing some research, I learned that lantern batteries are made of four long F-cells that are individually composed of a carbon core, a large quantity of manganese dioxide mixed with either ammonium chloride or zinc chloride, and lastly a paper sheath. Sometimes each battery will be individually cased in zinc but this was not the case for me.

1. I first cut off the top with a Dremel Tool to reveal the F-cells. They were fit in pretty tightly, so I had to do four more cuts down the sides in order to slip them out.

2. I then pulled out the carbon rods and peeled back the paper cover to reveal the manganese dioxide.

3.  Finally I added water to the manganese dioxide to dissolve the electrolyte and decanted into a filter to dispose of the separate them. You could keep the electrolyte, but I don’t know what it could be used for.

From this I got four black carbon electrodes and a large quantity of manganese dioxide. Any zinc collected might be worth saving as an electrode.