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Recent content by sciguyjim

  1. sciguyjim

    Keep razor blades sharp

    Here's a question, possibly related to old blades. I use an electric rotary shaver, I've never used any straight blade. Now and then, I get little nicks, usually on my neck, which almost bleed a tiny bit. These are not from the whiskers getting snagged and being forcably pulled out, that's a...
  2. sciguyjim

    Keep razor blades sharp

    Metalguy, I'm sure submerging the razor in alcohol accelerated the corrosion because of the water in the alcohol. Instead of just atmospheric moisture being in contact with the metal, now a lot of water was in contact. Leaving the blade in the handle could have also promoted corrosion if the...
  3. sciguyjim

    Nitrogen condenser

    Here are some sites I found with a simple search for liquid nitrogen production: http://www.waltainfo.com/EnNews/2002/Jan/15Jan02/Jan15e6.htm http://www.stirling.nl/sp/sp3.html http://www.fbodaily.com/cbd/archive/1997/10(October)/16-Oct-1997/36sol002.htm http://www.stirling.nl/sp/sp4.html...
  4. sciguyjim

    Keep razor blades sharp

    I don't know what kind of metal they are made of, but assuming you don't have a dessicator, or other dry place to store them, perhaps a thin layer of baby oil on the edge would protect it from moisture in the air. I assume they are kept in the bathroom, a relatively humid room. If you don't...
  5. sciguyjim

    Cooling and monitoring skin temperature

    Kevin, What I would do is monitor the temp with a high thermal resolution infrared optical monitor. No contact with a measuring device to affect readings. To control temp, I would design a sensitive device to gently blow air over the measured area. By mixing slightly warm air with slightly...
  6. sciguyjim

    Removal of epoxy paint

    Chicopee, I would not expect a mild, or strong, etch to remove the ghost on the aluminum. It would depend on what the ghost was made of (would it be attacked by the etchant.) Also, all the surrounding aluminum would need to be protected from the etchant aince without the (possible) protection...
  7. sciguyjim

    Removal of epoxy paint

    I don't know about epoxy paint, but I've heard that epoxy glue can be loosened with a chemical called: N-methylpyrrolidone It's easy to obtain, doesn't have a very high vapor pressure, has low odor and low toxicity, and can be washed away with either water or organic solvent. By itself it...
  8. sciguyjim

    Bellmouth design

    I remember reading once that, ideally, the "bell" should do more than just curve away from the mouth of the intake, as seen in the photo you referenced. I read that the optimal shape is for the edge of the "bell" to curl back on itself rather than simply stop in mid air...
  9. sciguyjim

    Xylene or Toluene Octane Boost?

    jhillyer, Aromatics do promote CCDs, when used long term, because they are notorious soot producers.
  10. sciguyjim

    Xylene or Toluene Octane Boost?

    Drwebb, I'm sure about the solids in gasoline. They remain in liquid form because it is a complex mixture. If purified they would solidify. I spent 8 years in the petroleum industry analyzing gasoline-like petroleum fractions, identifying the possible molecular structures for each compound...
  11. sciguyjim

    Xylene or Toluene Octane Boost?

    Patprimer, In refrence to your Jan 16 post, toluol is indeed the same as toluene. It's just an outdated name which most companies don't use anymore. The C6H5-OH you list (corrected for the proper number of hydrogens) is actually phenol. This is an acidic, sharp smelling compound that used to...
  12. sciguyjim

    Methanol reaction with aluminum

    Ok, but RC airplane entheusiasts don't have any trouble using methanol fuel in their aluminum plane engines. The cylinders are usually lined in some way but the whole engine gets hot and the fuel inlet and outlet are bare aluminum. RC plane fuel also contains nitromethane and lubricant but...
  13. sciguyjim

    Methanol reaction with aluminum

    I saw the following post on another forum and can't explain it... "A word about using methanol around aluminum. Here at work we have high pressure liquid chormatography systems that use methanol as an eluent. We were having problems with the system and it turned out that the methanol was...
  14. sciguyjim

    Air Flow Rate

    Ok, well, that's all the info I had. I guess I wasn't any help after all. I'll try to be more careful in the future.
  15. sciguyjim

    heat disapating coatings

    You might want to take a look at the post by Skelly in the "reflective coatings" thread in this forum. Here are some websites that mention various kinds of heat dissipating coatings (mostly for automotive use.) Maybe you'll be able to get some info from them. Gun Kote...

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