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  1. Be sure to mine PM for the many threads related...

    Be sure to mine PM for the many threads related to newbie use of surface grinders. There have been many threads on what very common mistakes to avoid when selecting, mounting, and truing wheels, for...
  2. I guess I’d have to ask ideal for what situation?...

    I guess I’d have to ask ideal for what situation? I suppose someone somewhere actually drills holes into castings for heat treating—-maybe aerospace or some other super-critical application. But...
  3. I guess I'd go back to my original post. I was...

    I guess I'd go back to my original post. I was looking for specifics and have gotten some pretty good specific suggestions. You may not agree with or understand my perceived need and that's OK.
    ...
  4. I see these devices are usually used to sense...

    I see these devices are usually used to sense overcurrent applications which heats an internal bimetal and opens the circuit. How would you be using it in my application? On the oven outer surface...
  5. In the final analysis I did order from Digi-Key a...

    In the final analysis I did order from Digi-Key a normally closed latching relay to place downstream of the primary relay. The cost was about 9 bucks plus 6 dollars shipping. (I could not find a...
  6. Haha, very clever. A pure silver bar does melt...

    Haha, very clever. A pure silver bar does melt at about 1763 F. Since my target temp when annealing iron is 1750F, that would be cutting it too close. But, otherwise, not bad. I could actually...
  7. Geez, a button! I should have thought of that. ...

    Geez, a button! I should have thought of that. ;-)

    Did you have any particular component in mind that is actuated by that button?

    Denis
  8. Very interesting thoughts. The possibility of...

    Very interesting thoughts. The possibility of using a GFCI breaker ran through my mind. But I did not (do not) have sufficient working knowledge to incorporate one as you suggest. I have a feeling...
  9. Thanks, Pippin, Yes, a redundant boarde would...

    Thanks, Pippin,

    Yes, a redundant boarde would work but would be an expensive (250-300dollar) option.

    The kiln controller is a "classic" US-made controller that is likely the most commonly kiln...
  10. I think you are referring to post 13. I guess I...

    I think you are referring to post 13. I guess I am a lazy reader and failed to find the nugget wrapped up in all the frilly wrapping and bows typical of ThermitIc prose. ;-)

    Denis
  11. On another forum someone suggested putting an NC...

    On another forum someone suggested putting an NC Latching relay in series with the main contactor. Seems like that should work OK. Anyone see a “fatal fault” with that idea?

    Denis
  12. and drawings of the parts. I’ve looked some at...

    and drawings of the parts. I’ve looked some at shunts and have not yet seen clear data sheets for the item I’m interested in. But, working on it.

    Yes, I usually buy electronic components from...
  13. Now isn't that interesting. No more welded...

    Now isn't that interesting. No more welded contacts----ever. The only reason this would not drop right into my control box is that the over-temp output is 12v DC and the coil wants 24VAC. And it...
  14. One question that occurs to me is does anyone...

    One question that occurs to me is does anyone have experience to KNOW how much current is required to hold "on" a magnetic contactor. If they are designed to run a motor, at idle the motor will be...
  15. Yup, 4Kw. Denis

    Yup, 4Kw.

    Denis
  16. I think I get what Bill is suggesting above and...

    I think I get what Bill is suggesting above and think that solution would do what I need. The “oral” schematic is as follows:

    Proper rated motor starter—->Normally closed relay (also driven by...
  17. Thanks to all for the above comments some of...

    Thanks to all for the above comments some of which hit the mark and some not so much. From my initial read, the second post suggests the type of breaker I hoped existed. I want to not depend on...
  18. What kind of switch will mechanically break a circuit in response to a 12V signal

    I have finished designing and building a small heat-treat oven 5 feet long, 16 inches wide and 12 inches high for stress relieving cast iron castings I make. It uses an excellent Bartlett kiln...
  19. I believe the job TR is doing is, in the boat...

    I believe the job TR is doing is, in the boat repair business, notoriously unpleasant. One of the seams (I think the garboard seam) is really difficult and I believe is the origin of the phrase...
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    Here are a couple vids to give you an overview. ...

    Here are a couple vids to give you an overview. On a different web site devoted to small-operation casting I am an active member and have posted lots of details about all aspects of foundry work.
    ...
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    In my small foundry I melt iron in 60 pound...

    In my small foundry I melt iron in 60 pound batches burning diesel. This methods costs many times more per pound melted than does induction. Even so, I can melt 5 pounds for about -$1.50. So,...
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    They are indeed glass on the Optivisor, but the...

    They are indeed glass on the Optivisor, but the glass is fairly soft—-no anti-scratch coating. So, be very careful how you clean them.

    Denis
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    So, an optivisor with 3 lens sets cost 23 bucks...

    So, an optivisor with 3 lens sets cost 23 bucks on Amazon. Optivisor has not been surpassed in the 40+ years I’ve used em. Until someone shows me something better I’ll continue to use them. Since I...
  24. JST, I just relooked at the video. Now I see...

    JST,

    I just relooked at the video. Now I see what you are seeing---plywood sheeting laid on the ground to make my pouring trolley run more smoothly. My humblest apologies for not realizing what...
  25. Whoa! Water injected UNDER the melt—-the worst...

    Whoa! Water injected UNDER the melt—-the worst possible situation. As they say “you can put water on (molten) iron, but you can’t put (molten) iron on water”—-trouble in the making. I’ll have to...
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