Bronze pour time

Discussion in 'Castings, finishing/ repair/ and patina's' started by John Homer, Jul 25, 2021.

  1. Petee716

    Petee716 Gold Banner Member

    Well, here's the thing:

    My pyrometer is made similar to what HT1 describes. 1/2" EMT bent at a lazy 90 at the end. At the hot end of the EMT I have a short stub of iron pipe with two threaded holes drilled in for set screws. One to hold the pipe onto the EMT and one to hold the gouging rod inside the pipe. All good so far. The disadvantage with the 12" probe I bought from McMaster Carr is that it doesn't come with wires attached. You have to weld them or figure out how to mechanically fasten them. The welding effort failed and I ended up stripping the insulation back on the extension wires and twisting together with the probe wires. This is no picnic either as the probe leads are quite stiff and the ceramic insulators on the probe are easily broken while trying to manipulate the leads.
    So... The probe gets slid into the sheath with the twisted connections sticking out the top, and the whole works gets guided into the pipe with the set screw in it and tightened down. The stiffness of the probe wires keeps the connections from touching the inside of the pipe.
    One of my concerns is overheating the insulation on the extension wires at the connections because of their proximity to the crucible. Sometimes it's aluminum and sometimes it's bronze, so I try to avoid prolonged exposure of the connection area to the heat.
    I would rather shut my furnace down for the shortest period possible while taking the reading, and on occasion my furnace will cool down to the point that doesn't roar right back to life because I've left my blower and compressed air on for the sake of my nozzle not getting overheated, while waiting for the pyrometer to get up to temp. That can sometimes result in the dreaded smoke plume that I try my level best to avoid when I reignite the furnace.
    So, I stick the end of the sheath over my exhaust hole until it starts rapidly rising above 400C or so, cut the oil, and then immerse it. I've got another 4 or 5 rods drilled and ready so I'm okay with the sheath's working life for now (as long as I don't bump them! lol.).
     
    John Homer likes this.
  2. HT1

    HT1 Gold Banner Member

    that sounds like a ton of unnecessary effort, is it for castFe???
    and which probe did you get?
    what does it cost?

    V/r HT1
     
  3. Petee716

    Petee716 Gold Banner Member

    https://www.mcmaster.com/3859K44/
    About 8 bucks.
    The furnace and burner handle Fe. The probe does not (2200F max).
     
    John Homer likes this.
  4. Jason

    Jason Gold

    Petee, try a mifco buddy. It's a really nice probe and worth the money. I'm the king of cheapskates and was tickled pink when I saw it. I think its tungsten.;) No more wonky probes or watching graphite burn up in short order. My old McMastercar probe is on my kiln with the pid. Nothing goes to waste at my house.:oops:
     
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