Page 464 of 481 FirstFirst ... 364414454462463464465466474 ... LastLast
Results 4,631 to 4,640 of 4810

Thread: what did you do in your foundry today?

  1. #4631
    Senior Member Zapins's Avatar
    Join Date
    Jun 2010
    Location
    CT, Hamden
    Posts
    2,163
    Fantastic I'll shoot for 2000 to 2150 f then. I'm at home depot now buying supplies so I'll see about another multimeter. You wouldn't believe the price of metal storage racks. Daylight robbery!

  2. #4632
    Hey, Zap.. I've got a spare meter from china.. It does the conversion for ya. It's in centigrade not F... Need me to mail it to ya? Please report back your findings on pouring temperature with the shell. It will give me a place to start and hope to avoid some misery. :-)
    Jason
    Visit me: WWW.HandcraftedLanterns.com
    "Sometimes by losing a battle you find a new way to win the war"
    -- Donald Trump --

  3. #4633
    Senior Member Zapins's Avatar
    Join Date
    Jun 2010
    Location
    CT, Hamden
    Posts
    2,163
    Hey jag thanks for the offer, what brand is your meter?

    I'm going to see how the voltmeter works first before I take you up on your generous offer. If the volt meter works then I'll probably just stick with that instead of making you go through all the hassle of shipping it. Converting from a table isn't so bad. The main thing I keep wondering is why doesn't my Chinese converting meter work? I feel like I must be doing something wrong because it is detecting a temp change, but it is giving me incorrect readings. I must be using it wrong. The problem is it has terribly translated instructions.

    I'll try out the new pour temp and let you know. I'll do it on some pieces I don't care much about and see how it works out. I'm hoping to pour on friday and maybe Saturday as well if I can't get through all my pieces in 1 day.

    I mixed a big batch of ceramic shell just now. Maybe 3 gallons worth of the stuff. Largest batch I've made so far in 6 years. It is much easier to dip parts in a large bucket vs. Spooning it over the wax in a small tub. I also upgraded from a pilfered kitchen whisker to a paint mixer in a drill. Much easier now and much less bubbling in the slurry.

  4. #4634
    It's one of these... You'll never get one from China by this weekend. If ya want my spare, say the word. http://www.ebay.com/itm/50-to-1300-K...1%26rkt%3D1%26

    When ya wired yours up, did you use actual type K wire for it? Any other wire will screw up the resistance and you'll get wonky readings. Mcmaster carr sells the right wire.
    Visit me: WWW.HandcraftedLanterns.com
    "Sometimes by losing a battle you find a new way to win the war"
    -- Donald Trump --

  5. #4635
    Administrator Site Admin
    Join Date
    Dec 2005
    Location
    Huatulco, Mexico
    Posts
    3,113
    Here are some more thoughts on measuring melt temperatures with a Type K pyrometer.

    First, this from a paper written by Wallace Venable at West Virginia University.

    Accuracy, Precision and Repeatability
    In general, non-scientists tend to mix up accuracy, precision and repeatability. “Accuracy” is
    how close a measured value is to the “true” value you wish to measure. “Precision” is how finely that
    value can be determined. “Repeatability” or perhaps “reliability,” is how closely you expect values of
    repeated measurements to agree. All three are important, but only up to a point.
    In practice, you want to be able to say is something like, “I know this glass anneals well if I
    heat it to 23 before turning off the kiln, and I know that sheet slumps nicely if I heat it to 39.” What
    23 or 39 corresponds to in Fahrenheit or Centigrade degrees really doesn’t matter if you are working
    glass in your own studio, not reporting to a scientific meeting. What you probably value most is
    repeatability, getting the same results each time. The way to get this is by careful observation, and by
    making sure your glass, probes, and heating system always remain in the same relationships.


    He is talking glass melting but it's the same with metal.

    My set-up is identical every time. I always use the same thermocouple, the same model and brand of meter, the same everything. So I know if I take a pot of Everdur to 47 millivolts before skimming I should get a good surface finish. I have checked my readings by using a reference point in ice water and the probe in boiling water and it seems accurate to a few degrees, but that is not important to me. 47 millivolts is what I look for when melting Everdur.

    Richard
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  6. #4636
    Senior Member evlwht-guy's Avatar
    Join Date
    Nov 2008
    Location
    Weddington NC
    Posts
    1,396
    Broke the glass window in my wood stove last night, so this morning I got up and cut out of steel plate to replace it until I could get a new one for it. Have to go to my parents 60th wedding anniversary today so the whole day is shot to hell. Maybe tomorrow I'll be able to get some work done on my hydraulic press project, hopefully I'll be able to get the mechanical Parts completely finished.

  7. #4637
    Senior Member Robert's Avatar
    Join Date
    Sep 2008
    Location
    Charlotte, Nascarolina
    Posts
    2,959
    Not cast...



    R
    "Whether you think that you can, or that you can't, you are usually right."
    - Henry Ford (1863-1947)

    Forklift Project
    Sand Mixer

  8. #4638
    Administrator Site Admin
    Join Date
    Dec 2005
    Location
    Huatulco, Mexico
    Posts
    3,113
    It's quite nice.
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  9. #4639
    Senior Member
    Join Date
    Nov 2012
    Location
    Ontario, Canada
    Posts
    2,184
    Very nice Robert... That's one of those neat little machining exercises that I always thought would be cool to attempt.

    Did you do it strickly in the lathe...?
    FLAME ON...!!!!

  10. #4640
    Senior Member evlwht-guy's Avatar
    Join Date
    Nov 2008
    Location
    Weddington NC
    Posts
    1,396
    Got a few things done...although due to the weather here...its 25 degress F .....this weekend will be a bust. Spending all day in front of the wood stove...which I had to repair last week due to having broken out the window in it. I replaced the glass with a piece of 3/16" steel plate. It is a good thing I did as it is so cold and the replacement glass I ordered hasn't arrived yet.

    Got work done on my hydraulic press http://www.alloyavenue.com/vb/showth...ighlight=press and finished my tool kit project. The toolkit project was in one way a bust...1 came out but the second didn't....also it was a ridiculous amount of work for something that would be easier to just do in foam. IE....making the part in blue foam would have actually been as good or better. I did a really crude job on the patterns but the job just wasn't worth doing in aluminum after all. HOWEVER....I was able to figure out the reason some of my lost foam patterns swell. If you remember I had this problem with my Korean License plate project. Her is a link to that discussion. http://www.alloyavenue.com/vb/showth...687#post197687

    Last edited by evlwht-guy; 01-08-2017 at 05:32 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •