Boolit Mold Hot Plate Temp?

[bdbruce]

I just finished building a Temp Controlled hot plate for pre-heating my boolit molds. I'm using Lee 6 bangers, Lyman 4,2 and 1 cavity molds. My hot plate has a Temp controller attached using a thermocouple. What would be a good temp to set it at? I tryed 475 and 500 F, the molds seemed to cast very well, in the past it would take many mold fillings to be able to produce defect free boolits. It looks like most of my boolits using the pre-heated molds look good. Does it matter what the mold blocks are made of?

On another subject, I have a 45 year old Lyman 311359 single cavity. After many thousands of boolits from it, the wood handles now want to slip off the metal handle tangs, I tried "staking" with a center punch the metal ferrules, this helped keep the handles on for a while, but now they are slipping off again. Anyone have any suggestions on how to cure this problem?

Thanks, Big Daddy Bruce

[William Yanda]

Does it matter? Fe, having more mass will hold heat longer than Al.

Handle problems? Drill and pin, silicone gasket stuff, JB weld all have advocates. Try Google.

[btroj]

Handles are an easy fix, pretty much any adhesive will work. I tend to use epoxy if I have it on hand.

A hotplate needs to be hot enough. More than that doesn't help. I turn mine on and let the moulds sit til they are hot. I tend to give them 5 to 10 minutes.

[Beagle333]

I use JB-Weld on the handles. One fix and you're good for life (or as far as I know). Pull em off... stuff some JB-Weld down in there with a popsicle stick and stick em back together. 'Next day, you're good to go!

I keep my makeshift mold oven on 350° (PID controlled). It rarely takes more than one pour to get it going 100% from there, and I know it isn't too hot for any mold that I have. (of any material)
Cooler might work, and hotter might work better.... that's just where I keep mine set, since you asked.
Happy casting!

[TXGunNut]

I'm new at the hot plate thing but I try to get them up to 350 or thereabouts and let the melt take it from there. I use an IR thermometer and point it at the sprue plate. I know that's not terribly accurate but it's the best I've come up with. Tapping the mould for a probe is probably best but I'm a big fan of the KISS principle.

[madsenshooter]

Find a many banded bullet like these. They'll tell you the perfect temp for your mold. When all the bands on one these cast perfect, any other bullet you cast with the same alloy at the same temp is likely to work very good for you.

[Hardcast416taylor]

On my older style 2 burner electric hot plate I placed a 7" square of scrap 1/8th" cold rolled steel plate on each burner for a measure of a barrier between the elements and whatever mold is on there.Robert

[bdbruce]

Hi madsenshooter,

I've been playing with alloy temp and my hot plate temp, now that I have controllable and digitally displayed temps for both. So far hotter seems better, running my alloy temp at 365 C or 689 F, my hot plate is at 525 F. I'm using Lee 6 cavity TL356-124-RN, 452-200-SWC, 358-105-SWC and a Lyman 4 cavity 35891 wad cutter. The Lee TL style is usually a good indicator of alloy/mold temps, so is the Lyman 38 wad cutter. Can the Lyman mold not fill fully if it gets to hot? the same for the Lee Aluminum molds.

Thanks for your response, Big Daddy Bruce

[bdbruce]

Hello beagle333,

It sounds like a easy fix, is the J-B weld a special High Temp stuff?
Your "Shotshells Ejecting" is a great photo!!

Thanks for your response, Big Daddy Bruce

[madsenshooter]

Seems to me that's what I need, more control. The bullet I pictured above is a real bear to get cast. If the mold's a little too cool I don't get fully filled bands. The alloy temp I have a handle on. The mold is nose pour, so I often get trapped air in the conical nose and sometimes even on the side of the bullet. Nothing like banana shaped bullets. Luckily, I can see where the trapped air is at, the bullet gets frosty there. Not to be confused with frosty all over. I've tried making the vent lines bigger, it helped some, but I don't wish to get them too big. Then I'd be getting spines on the bullet like I do another Eagan mold I have. I've been trying for a couple days now, I probably have about as many culls as I do good bullets. I don't mean really bad bullets, they go back in the pot. Bullets that are good enough for practice or plinking but not perfect enough for benchrest shooting, those are my culls.

[HeavyMetal]

Seems to me you may be overthinking this, LOL!

I started using a coil exposed hot plate 3 or 4 years ago, add a steel plate built for specific molds, some are set up for HP pins some set up to hold molds on side to warm up evenly and balance on the hot plate.

In any event I've found setting the Hot Plate to just under medium on the dial and letting the pot come up to temp gets everything ready about the same time.

My loss rate dropped to about Zero ( under 1% pending boolit design ) so I never found the need to fiddle with the Hot Plate any further.

[cajun shooter]

I was taught casting by my mentor in 1970 and he taught me to use a hot plate to preheat my molds. I have been using that way to cast ever since.
I now use a large single burner GE hot plate from Walley World, about $22. I turn the dial to high and set my molds onto the plate. To keep them flat so that they heat evenly, I put a bar of solder across the tops to balance the weight of the handles. I do this at the same time that my pot is coming to temp and melting my alloy. I always close out each casting session with a full casting pot of alloy. I have perfect bullets on my first pour with no discards. Take Care David

[Garyshome]

Some good stuff here. +1

[Iron Mike Golf]

I've used Gorilla Glue on Lee handles and it works great.

Off the shelf hot plate here (no temp control). The setting I use depends on the season. I cast in the garage and live in Ohio, so now it is set on 3/4. In the summer, it's set on 1/2. My goal is to have the mold up to temp when the pot is up to temp. Being in San Diego, you prolly don't have the same temp swings, so that takes care of one variable. Another is block size. Another is block material. A 2 cav aluminum block will need less heat added (meaning less time for preheat, a lower hot plate temp, or both) than a 6 cav iron block to get to casting temp.

Sounds like you found a good setting. I look at it this way: the hotplate gets the mold temp in the ballpark. Casting cadence and size of sprue puddle fine tunes it.

[Land Owner]

I took a leaking Mr. Coffee Maker, hack sawed off the split reservoir to just above the heater plate, and set my molds on that for pre-heat. Works great and didn't cost a thing - after several thousand pots of coffee passed through the Maker prior to conversion. Sold at almost all garage sales for under $5.00.

[Yodogsandman]

I took a leaking Mr. Coffee Maker, hack sawed off the split reservoir to just above the heater plate, and set my molds on that for pre-heat. Works great and didn't cost a thing - after several thousand pots of coffee passed through the Maker prior to conversion. Sold at almost all garage sales for under $5.00.

I did the exact same thing!!! Had plenty with broken decanters. Then somebody was selling a like new hot plate (in the box) at a yard sale for $2 and I've been using it since. It heats the mold to a higher temperature and allows me to cast perfect boolits much faster than the coffer maker warming plate did.

[rbertalotto]

325 to 350 degrees.....First bullet dropped is a keeper. I drilled a small hole in the mold and use a digital BBQ thermometer to keep an eye on it. A PID could also be used.

[edctexas]

I use an aluminum block holding a TC on the hot plate to measure the hot plate temp for a PID regulator. I found that a setting of 350- 395 F for the hot plate (as PID measured) gives roughly 425F on the molds that have a NOE temp probe. That seems to work for all but the smallest caliber molds. You don't really need to do this for ever. After you have done it for a while you kind of get the feel. But I am trying to control variables to see where processing could be improved. It seems like I do not need to do this but until I get casting to a certain consistency, I keep trying to measure things. When I find I don't need to do something, I drop it. The guys on here keep giving me so many ideas for how to improve! Love it. I do have the disease!
Ed C