molten metal temp

[garageguy]

After asking about casting Al, I am wondering what some of you use to check the temp of your melt? I have an IR temp gun that I used in the auto repair business, but it doesn't go nearly high enough for casting. Or do you just melt it and pour? If there was something reasonably priced I would be interested. I hate not knowing what I'm doing, although that is becoming more frequent as the yrs. go by. HAHA

 

[YYCHM]

You should be able to get a thermocouple and PID cheap from amazon that can handle the temperature range you need. I use that arrangement to control my lead melting pot.

 

[jcdammeyer]

I bought this cheap little meter from Princess Auto. It has a K Type Thermocouple input. The probe was made for my by the late Robert Grauman in Edmonton. The tube is stainless steel. The Thermocouple joint is welded into the tip. High temperature insulated sleeves I believe inside. The probe and wire are long enough that I don't have to be right over the crucible to measure the temperature.

 

[jcdammeyer]

Oh and here's the temperature chart I have hanging by the furnace.

 

[jcdammeyer]

Oh and here's the temperature chart I have hanging by the furnace.
View attachment 45574

BTW, in case anyone is wonder what "Pour under 0.5" etc. means it has to do with the thickness of the pattern being cast. Thin castings require higher temperature since it can cool too fast, chill and block flow to the rest of the pattern. Thicker patterns require cooler temperatures otherwise the metal shrinks too much as it cools and the top of the castings have dips. If that makes sense.

 

[Bandit]

It makes sense, been there, large risers, pouring holes, and feed gallery's can help sometimes too.
I followed Robert Grauman and company's casting adventures for a while, back some years ago.

 

[Tom O]

Here’s Myfordboys pyrometer.

 

[garageguy]

are all K type thermocouple meters capable of reading that high? If so, I guess the limiting factor is the ability of the thermocouple to survive the heat?

 

[garageguy]

OK, just did some googling, and K type go from -200 to 1300 C . Good to know. I think I can get something rigged up. That's a handy looking setup John.Thanks for all the info guys! ( sorry, not ALL K type go to 1300C0

 

[trevj]

I bought this cheap little meter from Princess Auto. It has a K Type Thermocouple input. The probe was made for my by the late Robert Grauman in Edmonton. The tube is stainless steel. The Thermocouple joint is welded into the tip. High temperature insulated sleeves I believe inside. The probe and wire are long enough that I don't have to be right over the crucible to measure the temperature.

View attachment 45573

I have the same PA Meter (used to go on Sale for around $10), made my own Probe by the simple act of pinching the supplied thermocouple in the end of some stainless pipe, and running a weld bead across the end. Thermocouples, are marvelously forgiving things, as long as you have the two wires fused into the end of the probe, you will get the correct results! If you dig through the correct suppliers catalogs, you can find sources for the various thermocouple wires, and the ceramic beads that might be used to keep them separate in the probe, as well as a great number of very much more expensive, (but not necessarily better) pre-built units.

I'll add that Rob G was a very good and dear friend, pretty near tireless in sharing anything he knew, to anyone that was interested, and I hold that as a pretty high bar to meet! He and Rupert Wenig, taught me a LOT about casting! And a lot of other related skills, like making furnace burners, how to prevent, or troubleshoot casting flaws, and a bunch more.
Robert was kind enough to leave to me his entire library of technical related books, among other gifts. I miss him! But I am glad to have known him, at least the parts I did.