Any idea what this K probe is?

[Mike W1]

Any ideas what this thing might be or any specs on it? It came with my PID, etc. Only markings on it are: VW-1 600V FT-2 CE A(and a partial character).

I have something similar I use on my Luber/Heater but that's threaded 1/4x20 and this appears to be about .228" dia. and I don't have a thread gauge. Being it came from China I'm guessing maybe 5.8mm but am not familiar with common sizes in mm's.

My harebrained thought was maybe epoxy it to the warming shelf on my Lee Prod. IV and see what's going on there temperature-wise. I know it warms my moulds well enough to get good bullets first cast. Obviously I have too much time on my hands and I like toys!

Any ideas I can put to work here? Would JB Weld be an appropriate expoxy to try?
http://i171.photobucket.com/albums/u310/Mike4245/K-probe_zpsde3d4143.jpg

[el34]

Lots of ebay PID package deals include that thermocouple. Trusting the postings they are type K which is one of the types compatible with most controllers so there's not much else you need to know about it electrically.

But the question is- where do you want a stubbie? I remember almost a year ago somebody poked a hole in the bottom of their pot and mounted that tc there. Neat idea but as I recall he had leaks.

[Mike W1]

Lots of ebay PID package deals include that thermocouple. Trusting the postings they are type K which is one of the types compatible with most controllers so there's not much else you need to know about it electrically.

But the question is- where do you want a stubbie? I remember almost a year ago somebody poked a hole in the bottom of their pot and mounted that tc there. Neat idea but as I recall he had leaks.

Actually another pix is simpler. That's my warming shelf on the left side of my pot. I was thinking if I could epoxy the probe to the bottom of it that'd get me the reading I'm curious about with my VOM. Just looked back at the ebay sheet and the thing is a M6 which is some kind of metric thread. I'm not curious enough to buy a metric tap though!
http://i171.photobucket.com/albums/u310/Mike4245/HPIM1075.jpg

[Beagle333]

Could you spot weld a nut onto the bottom or lower side of the pot and thread that into the nut til it touched the pot? Just brainstormin' here. :veryconfu

[el34]

Mike that's a neat idea, at least as an experiment to see if the readings are useful. I've been goofing with measuring mold temps on the fly while casting and the 6cav 230gr likes anywhere from 400-500deg. "Likes" means boolits look great and there's no eyeball detectable difference in their appearance.

[el34]

Just realized the significance of beagle's suggestion- the tip of the probe is where the actual tc "bead" is so that's what oughta contact the thing you want to measure.

[Beagle333]

I was just trying to think of a way to hold the tip of that against whatever he wants to measure, without drilling a hole in said thing. 8-)

[el34]

I was just trying to think of a way to hold the tip of that against whatever he wants to measure, without drilling a hole in said thing. 8-)

Your brilliance is exceeded only by your modesty.

[Mike W1]

I was just trying to think of a way to hold the tip of that against whatever he wants to measure, without drilling a hole in said thing. 8-)

Now you've got me thinking better. Think my brother has some connections to get a small piece of aluminum welded to the bottom. If need be after drilling a hole in that piece first, then welding, could file that piece to the proper thickness that the tip would touch the bottom of the actual shelf and a simple little lever would wedge the probe in place. A little dab of thermal grease and one should get a decent reading and the probe would be easily removeable. I'll see him for coffee Thursday and run it by him. By then someone here will have a better suggestion than this I'll bet.

[el34]

Are you wanting to measure mold temp or shelf temp?

[dikman]

Careful, or you'll give him a big head!;-)

Mike, working on the assumption that mine is the same type as yours, I checked the thread size and it's 6x1.25 (pitch). You could probably pick up a tap pretty cheap on ebay. Or you could drill a hole, push it in and seal it with high-temp silicone. Or you could drill and tap a hole for a coarse 1/4" thread (Whitworth, maybe) and forcibly screw it in! Wouldn't do the thread any good, of course ;-).

[Mike W1]

Are you wanting to measure mold temp or shelf temp?

Shelf - I'd think the mould temp would have to be a little lower than shelf. Have a little contact probe that I can use with the VOM and could get a comparison that way. Any way I accomplish this I'm gonna do it cheap.

[Mike W1]

Careful, or you'll give him a big head!;-)

Mike, working on the assumption that mine is the same type as yours, I checked the thread size and it's 6x1.25 (pitch). You could probably pick up a tap pretty cheap on ebay. Or you could drill a hole, push it in and seal it with high-temp silicone. Or you could drill and tap a hole for a coarse 1/4" thread (Whitworth, maybe) and forcibly screw it in! Wouldn't do the thread any good, of course ;-).

I'm kinda liking the idea of the hole and silicone. This isn't going to be a permanent fixture, just a check. Might have to check out a cheap tap though. I need another male K plug to do this anyhow. This forum just keeps me busy spending money one way or another. First the PID, then a bigger smelting pot, another PID. At least this one is going to have to cheaper than those were!!!!

[leadman]

I brazed a 1/4-20 T-nut that I rethreaded to metric to the bottom of my RCBS pot. Had to drill a hole in the case but it works really well. Just make sure you position it so the mold won't hit it when you slide it under the pot.

[el34]

Mike, you could possibly get an M6 nut at a hardware store. Then JB Weld it over a hole in your shelf. I'm wondering about the shelf heat being 100% felt by the probe tip though, with no convection loss.

[3006guns]

Can anyone explain the fascination of using epoxy, such as JB Weld? Don't get me wrong, I use it all the time......and I've learned that even the best modern epoxies will "let go" at higher temperatures.

Just get the correct size metric tap, about $5 at Ace hardware, drill and tap your shelf then thread the coupling in. A metric nut on the underside would keep it from being loose, however if your shelf is aluminum it will expand/contract quite a bit during heating cycles so keep checking it.

[el34]

Two nuts- one above the hole in the tray and one below. Maybe lockwashers. Position the probe wherever and tighten nuts.

Maybe the JB Weld suggestions are based on the actual or perceived typical availability of it, probably more common than metric taps and dies. And that it works. Doing it 'right' (tapping etc) appeals to many including me, maybe depends on the situation.

[Beagle333]

The manufacturer says that Original J-B Weld can withstand a constant temperature of 500º F. I don't know how hot your shelf is gonna get, maybe it isn't the stuff, maybe it is. :cool: I love it!

[Handloader109]

Heck get a tap. HF has a set for just a few $ if you want more than this size if not less than $5 for sure at hardware store

[Mike W1]

Gotta go to the big city tomorrow anyhow so I think I'll start by looking for a tap first. That way I can get a definite on the size of mine which probably is that 6x1.25 mentioned further up. Checked ebay without finding that particular one. Then if it's a go will tap a piece of aluminum and have it tacked onto the bottom of the shelf and fit it from there. Obviously I dont want anything protruding onto the top of the shelf. Just have to see what's around my area first. Worst case toss the probe into the bottom of the bench, this ain't a real important idea I had. Certainly not worth too much time or money.

[Mike W1]

Went with a metric nut JBWELD'd to bottom of shelf. Here's my notes on the project thus far. FWIW
Contact TC Probe w/VOM ( C )
TC mounted to shelf bottom with nut & JBWeld ( M )
TC in lead pot with REX C100 PID ( R )
IR Thermometer ( IR )

COLD START READINGS
Room Temp 60° F
LEAD
R = 15° C (59° F)
C = 67° F
IR = 67° F
SHELF
C = 70° F
M = 69° F
IR = 66° F
MOULD
C = 71° F
IR = 66° F

READINGS AFTER STARTING FURNACE
ELAPSED TIME 11 minutes
LEAD
R = 150° C (302° F)
C = 387° F
IR = 255° F
SHELF
C = 214° F
M = 224° F
IR = 79° F
MOULD
C = 188° F
IR = 108° F

READINGS AFTER POT HIT SET TEMPERATURE
ELAPSED TIME 23 minutes
LEAD
R = 335° C (635° F)
SHELF
C = 254° F
M = 253° F
IR = 95° F
MOULD
C = 195° F
IR = 118°

NOTES: Used the IR thermometer to verify they aren't much use to us in
casting bullets AND THEY AREN'T!
The little contact probe needs something to stiffen the end as it's hard to hold
in contact, particularly to a hot surface. (Toothpick)
TC probe in lead pot wasn't submerged at start, dropped in when temp hit
300° C (572° F) This is about the temperature area I've noticed that my
pots drip a bit till they're warmed up fully.
Warming shelf on pot that was tested for temperature
http://i171.photobucket.com/albums/u310/Mike4245/HPIM1075.jpg
K probe JBWELDed to bottom of pot shelf
http://i171.photobucket.com/albums/u310/Mike4245/K-probe_zpsde3d4143.jpg
The little contact TC probe
http://i171.photobucket.com/albums/u310/Mike4245/ContactProbe_zpsad43dec3.jpg

[el34]

Sounds like you got a good mold kickstarter! It'll be interesting to see how it all works for you while casting.

[dikman]

Sometimes I think retired people have too much time on their hands :bigsmyl2:.

[minmax]

Spring for a tap at local AutoZone, about $3.00. At least last Month when I was working on my brakes. Their metric nut and bolts are more than your local hardware . I like JB Weld too, but I'd go with the tap.
Good luck and keep us posted.

[Mike W1]

Sounds like you got a good mold kickstarter! It'll be interesting to see how it all works for you while casting.

Been using those little shelves for years. Normally by the time the pot reaches casting temperature the first bullets are good so I know they do the job. Was just curious what those temperatures were and these TC's at least give me a guess. I was pretty sure my IR thermometer was a joke and this at least proved it to me.

[Mike W1]

Spring for a tap at local AutoZone, about $3.00. At least last Month when I was working on my brakes. Their metric nut and bolts are more than your local hardware . I like JB Weld too, but I'd go with the tap.
Good luck and keep us posted.

Actually I don't think a tap would have been any more accurate than welding the nut to the shelf. The sensor is in the tip of the TC so with it threaded up tight against the shelf bottom via the nut and the thermal grease it's making good contact this way.

[Mike W1]

Sometimes I think retired people have too much time on their hands :bigsmyl2:.

Definitely so! And you get a lot of it with LONG Iowa winters.