Do I really need a thermometer? (And why?)

[GeneT]

Hi All,

OK - I've rabidly (no, that's not supposed to say 'rapidly') increased my casting in the last few months. I've gone from casting one bullet to about five + two different shotgun slugs. I'm getting good results as-is, but I keep seeing people say that a thermometer is a "must have".

The only thing obvious to me that a thermometer might improve is less oxidation of the melt - am I missing something? Do I really need a thermometer?

GsT

[Muddy Creek Sam]

It helps to keep the zinc out and helps to diagnose problems.

Sam

[Shuz]

I cast without a thermometer for many years, and "got along" OK. After I got one, I wouldn't want to cast without one! It makes the whole process a lot simpler. Is there anyone out there who has tried a thermometer and found it wasn't worthwhile?

[Charlie Sometimes]

If you are working with unknown blends of lead alloy, I think it helps some to use one. I tried to blend them until they solidify at similar temperatures, hopefully making them near the same alloy percentages that way. You need an accurate thermometer to really be able to tell about the real differences in the alloys, and most of the commonly available one aren't readable to the degree you need, IMHO.
Even with one, it is still just a guessing game. I end up just shooting the unknown blends for practice/plinking loads, and keep the known stuff for accuracy and hunting loads.
I have just about quit using one though- I find all my alloys are casting better running hot melts, so I just run them all that way lately. Hot enough to fill properly, hold proper mold temperature, and that is where I stop.
Hardness is the next thing I worry about in relation to this subject.

[RobS]

You do not have to use a thermometer as a person can find rhythm with their pot settings and casting rate and take note to what is going on. I had done it this way for a long time however with the arrival of a thermometer a while back now I wouldn't cast without it. It is a tool and nothing more, but man it sure is nice to know exactly what is going on with the alloy. If a person had a PID temp controller on their pot it would be easier to judge the alloy without a thermometer, but with the pot I use (Lee 20lbs bottom pour) it regulates the temp of the alloy with a rheostat which is located inside the body's housing unit. Ambient temperatures outside in the garage change from season to season and so does the rheostat that regulates my alloy temps so my pots setting in the summer is not the same as in the winter.

It's also nice to know where a person is at as some molds like temps that others don't. Many times I will cast two different molds and if one likes the alloy a hotter temp I'll start with that one and later move on to the other mold as I put in a bit of ingot or sprues to cool down the alloy. No time wasted trying to heat up the alloys or guess when the temp is right for the second mold.

[NSP64]

I started out without one. Bought one noted my settings on the pot. Don't use it much now.

[mooman76]

I have been casting allot of years and have never used one. I think it is somwhat of a handycap for a begginer, they get hung up on it too much. Sometimes it won't let them think the problem through. They think I cast at x number of degrres last time and now I am still there an can't cast so they can't figure out what is wrong. You learn allot by not having a thermometer on how to sence what your different moulds need to produce good bullets.
I am not knocking thermometers by any means. I think they are a nice thing to have but they are not a must have. I just don't feel I need one at this point in my casting life. Like stated they can help diagnose problems or help keep your zink out of the pot. The way I always kept zink out was I did small batches and poured my ingot quick so I never leat the lead get hot enough to melt zink. The funny thing was I was doing it when I first started and din't know I was doing it, but back then zink WWs were a rare thing.

[qajaq59]

I wouldn't say you "need" one. But they are handy.

[Poygan]

I had one and found I used it very little. Sold it to a gent on this forum and have not missed it. I melt down the WWs in a large Lee pot and use a low temp and stuff floats to the top. (Have yet to find a Zinc WW). I use a Lee bottom pour for the boolit casting. Perhaps sloppy and unscientific but it works for me.

[mpmarty]

You don't need a thermometer to cast any more than you need a speedometer to drive a motor vehicle.

[Calamity Jake]

I started out without one. Bought one noted my settings on the pot. Don't use it much now.

Me too.

[mold maker]

Our grandparents didn't have one, and they fed their families with cast boolits. There were enough boolits cast without a thermometer to feed the rifles for wars.
They are an accessory that may make it easier to be a little more uniform in size and weight.
As stated above it's too easy to get hung up on using THINGS to take the place of common sense and experience.

[Doby45]

You don't need a thermometer to cast any more than you need a speedometer to drive a motor vehicle.

But just like a speedometer, they are nice to have.

[white eagle]

I just started casting and have a bunch to learn yet
however I just keep an eye on my pot if it starts to take longer to have the sprue set up I turn it down a bit,,,,,,,,,,
seems to work at this point

[ghh3rd]

I especially use one when melting my WW to help keep below the Zinc melting point.

[No_1]

I found that it helped me. I usually don't even bother trying to cast below 700 degrees. Depending on temperature and humidity it may take more or less time for the lead to reach that point. The thermometer lets me know when the melt is at the temperature I want.

When I first got my thermometer, I used it with my lee pot. Once I added a PID controller to it I did not need it because the PID gave me the temperature. With my Master Caster, the pot is suppose to be more accurate but I have found (using my thermometer) that the pot is off to the amount of -25 degrees. There is a way to adjust this pot but I have not done it because I am going to PID this one too.

Like others said:
1) it is a good troubleshooting tool
2) You can live without it but it may make things much easier.
3) They are really not that expensive.

[BD]

I cast a lot of boolits without one, but I didn't really understand what was going on until I got one.

I wouldn't let the lack of a thermometer keep me from casting, but I wouldn't want to give mine up now that I have one either. In addition to teaching me what temps particular molds want to run at, it allows me to keep my alloy at a more constant temp as I'm running down the pot and adding ingots.
BD

[MtGun44]

Not necessary. I never use mine in normal casting.

Bill

[Bret4207]

It's an accessory that can help with basic issues. Beyond that pot temp is relatively unimportant and you probably won't use it much.

[Bass Ackward]

It's true. The world is full of get bys and the decision maker is the user. As casters, we do or don't do things for three reasons:

1. Cause it's cheap
2. Cause it's fast
3. Because it's a PIA

Somewhere on down the list we find

141. Because it is better.

You don't have to weigh or throw charges, you can dip. Comes with limitations.

You don't have to use just one brand of primer, you can mix and match primers of the same strength and type. But this comes with disadvantages.

You don't have to use all the same brass and life goes on.

And you don't have to use a thermometer either. Along with everything else that you read here , it can be done without.


My RCBS pot has 25 degree temp swings and will raise temp by just over 100 degrees from the top of the pot till empty without adjustment. That's 150 degrees from extremes. I have over 30 molds of different weights and mold materials that have sweet spots all over the place. It don't hurt to have the thermometer there except during fluxing, so it stays in. And I use it to what I believe provides a huge benefit. I can get into the sweet spot faster and stay there longer than without it. If I don't use a mold for a few years, no problem.

Now if I am dipping, it always gets in the way. And with the weight of the lead and the heat in the dipper along with the slightly enlarged diameter spout mitigates the importance of temperature to get good, consistent fill. So I don't use it but to start out.

So if you ever read Threads about why some guys prefer dipping to bottom pouring, or steel to aluminum molds, smoking molds, use of tin, reject rates, or many other subjects, put two and two together and that thermometer can be cheaper, faster, less irritating and give better results than the negatives people use to justify not buying / using one. Cast bullet making / shooting is about us correcting things that we cause during other steps to make things work.

But you still don't need it.