RCBS Thermometer Calibration

[Themoose]

I question the accuracy of my casting thermometer(RCBS)... so i put a coffee can full of water on my stove until it boiled and placed the thermometer in it... never reached 200F, let along 212F.. This particular thermometer has no adjustment nut on the back of it... I'm afraid to twist the housing as it may break... anyone know how it can be calibrated?

thanks,

TheMoose

[jmort]

Aside from info you get here, contact RCBS.

[uncle joe]

if your at a fairly high elevation the water will boil before 212 deg. and once it boils it will not get much hotter than 212 with out building pressure.

[Roosters]

This will give you a ruff idea if you know your elevation.

http://i1173.photobucket.com/albums/r600/threescrew3/W2_zps83a06f2b.jpg

This shows 200 at 6000 feet.

[Themoose]

Thanks folks,

I have searched the forum, but could find nothing on thermometers without the nut on the back for adjusting... altitude is not the problem as I'm @ 900ft... Looks like my mistake for buying something without putting it into my hands first...think I got it from Midway or Natchez... not their fault either.. live and learn.

Thanks for the help

[doctorggg]

doesn't help you one bit but my RCBS is the same way. I don't bother using it. It's more than 20* off.

[doctorggg]

Google: Tel-Tru Manufacturing and look up SKU# 23100566 (272)


BIG Green Egg, Primo, Grill Dome, Kamado Replacement Thermometer LT225R, 5 inch stem, 200/1000 degrees F BIG Green Egg, Primo, Grill Dome, Kamado Replacement Thermometer LT225R, 5 inch stem, 200/1000 degrees F



Model: LT225R
LT225R (BIG Green Egg/Primo/Grill Dome/Kamado Thermometer) 2" Dial x .150" Diameter, 5" Stem, 200/1000 degrees F (10 degrees/Div), Glass, Recal Nut, Pan Clip
Lead Time: Stock to 14 days


Price: $20.95

This may be an old price but this is the same thermometer I have paid big name companies 2x as much for. It's also recalibratable. I bought 2 some time ago and have zero problems. Stepped on my Lyman and broke it. Of course you know what the problem is with RCBS.

[OuchHot!]

I had two different dial type casting thermometers over the last 35yrs, one was lyman and I think that the other was rcbs. Neither was anywhere close to real world at 500F and above. What I use now is either the PID readout or a fluke. There are a lot of electronic meters for $30 or less that will take k or J type thermocouples. Quite a few cheap volt/amp/R multimeters have this function and come with a thermocouple as well for under $50. ymmv, but I recommend going electronic on the thermometer. I have the ability to check calibration at melting temps and do not feel that what you see at 212F is relevant to 600F on a cheap dial thermometer.

[Themoose]

I ordered the Tel-Tru 225R this morning. But waschthinking that I may also want to do something like OuchHot! suggested in the future.

Thanks for sharing.

TheMoose

[KYCaster]

I have the ability to check calibration at melting temps and do not feel that what you see at 212F is relevant to 600F on a cheap dial thermometer.


That says a lot right there.

If your equipment has not been calibrated then you have no idea what the actual temp. of your lead is.....

.....but, does it really matter? If you're just concerned with getting the same temp. today that worked well yesterday, then it doesn't really matter if your thermometer is 20 or even 100* off. As long as it says the same thing today as it said yesterday you can expect the same results. That's why the dial on your bottom pour pot is numbered 1 thru 9 rather than in deg. F. If 8.5 on the dial works the same today as it did yesterday, it doesn't matter if that doesn't tell you what the actual temp. of the lead is.

Don't get your panties in a wad over stuff that you can't control. Find what works and figure out how to repeat it.

Jerry

[OuchHot!]

I have to agree....I felt the electric pots (first was Pro-melt followed by Lee and Waage) were such a wild leap above the stove top that I never noticed that there was no correspondence between setting on the knob and end temp. It was only after getting a sizeable variety of molds that it became useful to use a thermometer.....and then only to speed the time to the first good boolit. A good eyeball and experience produces a lot more good boolits than no experience and a PID in my view. Still, PID and electronic thermometers are dirt cheap now and why not if you can?

[Shepherd2]

I agree with KYCaster. It doesn't matter to me if my thermometer is accurate or not. I use it as a reference just like I did with the numbers on the dial of my pot before I had a thermometer.

[double bogey]

I built a pid controller, but before that I used a Fluke I use for work. The fluke told me how much my pot fluctuated. The fluke and the pid control read 2° apart at 675°. You can find cheap electronic thermometers on the internet. Anything fluke is expensive but an imersion probe should be easy to find on the internet cheap, or buy a probe for a few bucks and add a type k connector.

[OuchHot!]

Bruce381 has a thread in the lube section referencing an ebay PID for $16.50 that has internal relay switching. It looks just like one I bought several years ago (paying $30 if I recall) and my experience with it is very positive. It is hard to imagine this stuff getting cheaper and k type thermocouples are cheap. It is always good to use purpose made thermocouple plugs and wires as each dissimilar metal to metal connection forms its own little thermocouple which can cause a couple of degree shift. The plugs and wires from Auber and others will add a few dollars.

[monadnock#5]

The fluke and the pid control read 2° apart at 675°.

If knowing the temp of your pot is critical, one thermometer won't do it. If it goes bad, you won't know it until your boolits go bad. You need two, one to monitor the melt,and one to monitor the other.

Double bogey's setup is perfect in that regard. You could use your current thermometer with either the PID or the Fluke and save a few bucks though.

[double bogey]

The thermocouples are cheap though. A 2 lead fluke cost over $300, and it won't come with a thermocouple suitable for our use. That one from fluke is anothe $80 or so bucks. You can buy a suitable electronic k type thermometer (import) for $30 or so, and useable thermocouples are $8 to $15 on amazon. Add a connector and you are ready to check molten lead temps.

I have had the fluke for 15 years, it is well used, and I got my moneys worth. If I needed a backup for work, I would get an import. Mostly I use a thermister thermometer for refrigeration, as they are less likely to be affected by outside influences.

I cast a few boolits with so - so (lots of rejects) results, then I read about pid controllers on this site, built one, and my boolits are way better than casting with temp swings. I'm looking for other things to control with the pid.

[monadnock#5]

There is a member here who goes by the handle Texasflyboy. A number of years ago he came up with a group buy of sorts. A lucky few members were able to purchase a fluke "style" handheld meter with thermocouples at a very reasonable price. What the OP needs is out there.
I'm sorry I can't be of more assistance at the moment. I fell on the ice yesterday, and I'm pretty sure I cracked a rib. Going down stairs to my casting dungeon won't be an option for at least 24 more hours.

[double bogey]

http://www.amazon.com/AGPtek-Channel-Digital-Thermometer-Thermocouple/dp/B0084JQL1Q/ref=sr_1_1?ie=UTF8&qid=1393713563&sr=8-1&keywords=thermocoupleermometer

http://www.amazon.com/Amico-50-700C-Thermocouple-Temperature-Sensor/dp/B00D8337YW/ref=pd_sim_indust_3?ie=UTF8&refRID=1YA65GB2AYK6WX9W5D0P

These will work plenty well for checking against a dial thermometer. Imports, but cheap.

[Themoose]

Today was my first chance to use the Tel-tru thermometer...I placed into the melt and let it stabilize for about 5 minutes. I use a propane single burner stove and large cast pot holding about 30# of alloy. I adjusted the flame in small increments, waiting each time for the temp to stabilize and was able to maintain a constant 700F temp as I cast.. I would pace myself to maintain that temp... the result was some of the best looking bullets that I have done for awhile... thinking that previous sessions I was casting too high and temp range was pretty large...I cast about 300 LFN's for my .44... with 14 that were underweight/fill from the beginning bringing the mold up to proper temperature and they were one grain under the others. I may still look into a PID for bottom pour, but the pot and ladle session today was as smooth as silk for me.

TheMoose