Tip of the Day--Shop Towels

[Al Sheik Yerbuti]

Did you know...
that those red shop towels that auto mechanics use were litmus? When you wipe up acidic solutions they will turn blue. They can be rinsed and treated with (for example) sodium bicarbonate and returned to their red color. In my home lab, I will pretreat some of these red towels with sodium bicarb and allow the salt to dry on the towels; I will then use them to wipe up my many spills of various acids. I have then a good indication of whether my spill has been sufficiently cleaned or whether I need to contain the spill any further. These red shop towels are available in the auto section of Wal-Mart or any auto parts store.

If you have any great tricks like this, please--post them as a Tip of the Day!

[209]

Hmmm, good idea, though I dont spill acids :D. I never have really been able to get litmus. There are no decent chem or equipment suppiers in my area. But now that I know, thanks! I have seen these "rags" at Lordco and I will pick some up next time I go to get some sulferic.

My tip of the day: (it may be a crappy one, but w/e) Plastic knives! - these make the worlds greatest stirring rods! I find I can mix much easier and solid chems that need to be dissolved into an aqueus solution can dissolve much faster! Easy and disposable.

[stupid939]

The shop towel thing is a good idea. I noticed that they changed colors awhile ago, but didn't pay much attention to it. I also didn't know you could neutralize it and return its original color.

If you are looking for litmus paper, you can get some very cheap, yet quality, paper from American Science and Surplus:

http://sciplus.com/singleItem.cfm?terms=941&cartLogFrom=Search

My tip of the day... Oh, this isn't really a tip, but it makes things a lot easier. For measuring and mixing solid chemicals, go to the store and buy some of the little dixie cups. They are the ones that are about as big as a shot glass, but you can get a few hundred for a few dollars. I use these for pyrotechnics and other stuff, and they are easy to label with a sharpie.

[Jacks Complete]

My tip? The blue paper towels you get work the same as the red ones. But they go red.

To make your own litmus paper/dye you can use red cabbage. It goes from red (acid) to weakly green-yellow (alkali). Full info at http://chemistry.about.com/library/weekly/aa012803a.htm

I also use the cups idea for toxic chems, as they are cheap enough to throw, removing issues with cross-mixing and cleaning. Chop a hole in the base for a disposable funnel.

[hydra]

sheesh....I've been using both the red towels and the blue paper-towels for YEARS...and I never knew that!

thanks much for a good tip.

I wonder if anyone has compiled a good list of readily available substances useful for indicators...pH and other... ??

I.e., certain plant-extracts, etc., like the cabbage juice idea given above.


edit: whups...seek and ye shall find...google produced this:

http://chemistry.about.com/cs/acidsandbases/a/aa060703a.htm

Home and garden Indicators

Actually, that might be a useful site for other things....a number of useful-looking items listed on the page up one level:

http://chemistry.about.com/od/chartstables/Chemistry_Charts_Tables.htm

[209]

Many of you may already know this, but I will share it anyway. All the hotplates in science catalogues are to damn expensive and the hotplates for kitchen use are unsuitable for my needs. My DIY side kicked in and I bought the parts for a cheep but durable small hotplate.

Buy the smallest heating coil for an electric stove (or get the size of coil you perfer) and build a little stand for it that is about 3 inches tall (I welded togeather a couple pieces of sheet metal and ended up with a nifty little stand) then wire in a little dimmer switch and there you go! Add on a plug and turn to the heat setting to what you want. Most heating coils from stoves are designed for 220V so plugging it into a 115V outlet will be perfect because the coil won't glow red hot (when would you need that hot anyway?)

If you have any other DIY lab ideas lets hear them!

[hydra]

Tip o' the Day is a good idea. I wonder if a mod should change the title...or move these non-towel tips to a newly-titled thread?

Anyway, here's my Tip o' the Day...

Whenever you need to run several wires together, you can easily produce a real nice "twisted pair", or twisted-multi, using nothing but your vise and DeWalt drill.

Take your several wires, get the ends all even together at one end, and clamp them in the vise.

Pull them out so they're all equally taut, and clip the ends even to each other. Now put a nice tight twist at the end, then chuck that twisted bundle up in your drill. Keep tension on the wires, and spin that puppy up!

You'll end up with a very nice even and tight twisted 'cable'.

If you don't have a vise to hold the far-end, you can use vise-grips or a C-clamp, or even your girlfriend... :D