Good source for a suitable thermometer ?

[BigSlick]

Looking for a thermometer to use with smelting/casting.

Lyman and RCBS make them, but neither seem ideal to me. Both are expensive (for a thermometer) and seem to be a little longer than convenient.

I know it has to be long enough to clear a ladle or when you add ingots, but I'm hoping there is a better mousetrap out there.

What do you guys use ?

Thanks

BigSlick
________
GODDESS WORSHIP FORUMS (http://www.religionboard.org/goddess-worship/)

[utk]

I found a thermometer for measuring the temp of smoke-gases in a chimney much cheaper than Lyman or RCBS. And shorter too.

[Dale53]

I didn't go for cheap, but for a more accurate thermometer than my Lyman. I went with "The Antimony Man''s (Bill Ferguson) thermometer and have been VERY happy with it:

http://www.theantimonyman.com/thermometry.htm

Dale53

[utk]

Being cheap doesn't necessarily mean inaccurate. My thermometer maybe is "cheap" because it is sold to "a larger market" than us small bunch of boolit casters?
Anyway, i don't have any means of testing the accuracy anyway, so I'm just happy...

Urban

[grumpy one]

You essentially have a choice between mechanical (making use of the expansion of a metal when it is heated) or electrical (using the temperature-based potential difference created at a junction between two dissimilar metals, known as a thermocouple). Mechanical types are nominally cheaper, but are not especially accurate and are physically limited by having to have a direct mechanical connection between the probe and the readout.

If you are prepared to make the effort you may find a surplus electrical device that has become obsolete in some industrial application. Just note that there are at least two common types of thermocouple in use, and the readout device has to be suited to the type you are using, so it's best to buy a complete system rather than scrounging for the thermocouple and readout separately. Make sure it extends to a high enough temperature to be useful for smelting - say about 1000 degrees F.

Some fairly cheap and commonplace digital voltmeters take a thermocouple as an accessory - just make sure it can handle 1000 degrees F.

I use a very old analogue-scale thermocouple readout that does not even require a battery. I think I paid about five or ten bucks for it when some instrument lab was throwing it out as obsolete, with three thermouples each about a yard from junction to plug. It's about fifty years old now and is good for at least another fifty. It's relatively bulky however - the dial is about eight inches across. I put the readout a couple of feet away from the lead pot so I won't get any lead splashes on it.

Geoff

[Bucks Owin]

I found a thermometer for measuring the temp of smoke-gases in a chimney much cheaper than Lyman or RCBS. And shorter too.


Where did you find that critter?

I have a "gauge" on my woodstove that goes to 850 degrees but it just sticks on the stove's flue or pipe with a magnet. Is that the kind you mean?

I'd want something with a probe....

Dennis

[utk]

Dennis, we have those "external" gauges here in Sweden too, but the one I found has a 10" probe and a 3" dial. Looks just like the Lyman/Rcbs at 1/3 the price. Don't know where you would find one in the US...

Urban

[georgeld]

After more than 40 yrs messing with trying to guess temp and reading about how much better my life would become I went ahead and paid the $40 for a Lyman.

Hate to admit it, but, my life of casting has improved, so have the results. It ride's in the pot while I'm casting all the time. I cast according to the temp.
Nothing less than 700 and try to keep it near 750.

Once while getting more ingots laid out and left it cooking. It read a bit over 900 which surprised me with a Lee's propot. It was nearly full too.

This is one item I've found that was a great improvement to my system and would recommend it to anyone.

George