Heat soak

Walks

Well-Known Member
I usually empty My pots at the end of each casting session. Then clean the crucible and disassemble and clean the spout mechanism.
I never know what kind of alloy I'm going to cast with or even when I'm going to cast again.
I cast on My patio, so I have to break down & setup my casting gear each time.
 

popper

Well-Known Member
Yes, let the pot 'simmer' for a while before casting. If you leave alloy in the pot, it forms various 'alloys' when it cools so those need a while to 'un-form' when liquid. If you look at the charts, alloy changes it's 'makeup' as cooled. Age hardening is just the molecular motion in the solid. Tin aggravates it.
 

358156 hp

At large, whereabouts unknown.
I like to let the pot sit for awhile at full temp and give it an occasional stir upwards to encourage any potential trash to float to the top, especially after a couple of rounds of fluxing. I think it really helps with some of the mutt alloys I work with.
 

Mike W1

Active Member
Have reread the thread several times and can't prove or disprove any of the theories posted. BUT, my take is that few have actually measured the actual temperature of the mold when it's casting at it's best. That's what is important far as I'm concerned. And I've done a LOT of temperature checks and weights of the first bullet cast.

Don't have any idea of how, as a for instance, a dremel speed control does it's thing to control the heat of a hot plate but feel sure it's not gonna do as well as a PID would do on it. The tests I did with TC's only confirmed to me if you want REPEATABILITY, a PID would probably be a lot better. The particular mould I used likes around 320° to 330° F. And it takes some heat to get it there for initial heatup plus being able to
be able to rest the mould on the hotplate and expect that'll be in that same range. In the case of that mould a setting of 440° will do the job. The 20 odd minute warmup of my pot along with the hotplate gets that job done. By the same token I didn't want the mould much hotter than 320-330° when it was parked there for a "rest", just maintained.

Far as scraping I use either my spoon or a modified hacksaw blade for that chore. When I melt down my lead for bullets I may not do as perfect a job as some profess to do but I don't need paint stick chars being added to my pot. The only thing other that goes in the pot is a dob of beeswax period.

For that matter I don't as a rule hit the pot below with beeswax after filling it from the feeder pot above which always gets the beeswax stir and scrape routine. I "feel" like it's already been cleaned about as well as I can get it. The one exception to this is on initial startup both pots get the beeswax as I always remelt the sprues from last session at this time.

One other question I'd have for ladle casters would be how do you get the surface of your melt completely free of crud? I usually have a bit of it after spooning things off and I don't think the small diameter of the Lee 10# pots is helping me any there. Have tried to grind the spoons down to match the curve of the pots but maybe I'm not getting it quite right. At least it's up there and out of the melt I guess.
 

Brad

Benevolent Overlord and site owner
Staff member
My pot always ends up with crud on the surface and by using a Rowell ladle it is not an issue. A Rowell ladle is designed to pour from the bottom of the ladle so crud floating on the surface doesn’t matter.
I don’t think there is a good way to prevent oxides from building when using a ladle as the form on the ladle as you cast and are then transferred to the pot with each cycle.
 

bruce381

Active Member
thread swerve warning

how do you work a H+G a with the screws sticking out on a hot plate that is flat?
Cannot drill counter sunk holes cause my hot plate is flat with no open element.

The mold only contacts the hot plate by the 2 screws I do cover the hot plate with a coffee can to keep in heat but cannot get 100% contact.

Also yeah i find letting the alloy set helps also brings up some crud after 10-15 minutes maybe thats why it casts better
 
Last edited:

Brad

Benevolent Overlord and site owner
Staff member
Take a piece of steel that is thick enough for holes to let the screws sit in them without bottoming out.

This becomes a heat transfer plate between mould and hot plate.

I would probably just place the mould on the plate and let convection along with conduction thru the screws do the work. Even turn mould upside down to get the top some heat too.
 

Winelover

North Central Arkansas
CW had a good idea using a panini grill. We had one collecting dust so I repurposed it. When I used a hot plate, I didn't even put a coffee can cover over it. Just and old circular saw blade lain on top of the coil. Worked for NOE's RG molds with they're uneven bottoms.
 

Jeff H

NW Ohio
I started using a hot-plate several years ago - probably after reading about it here. I got tired of the hokey-pokey pre-heat method on 6C moulds, where you cast in one then two, then three cavities, until all six throw good bullets. By the time I got up to six cavities, it was time to refill the pot. I stick a TC from a cheap meter in one cavity and make a mental note of at what temp YOUR moulds cast well.

Having worked in industrial process heating for several years, I can't just "warm" something or just "heat" something - I have to be able to measure it. Not that this is THE way, but it's an obsession based on solving process heating issues AND I have the stuff to do it with. If it's not your core competency, and what works for you - do THAT.

My pot is controlled with a PID controller, because I was too cheap to buy a thermometer, while I had PID controllers and TCs sitting around. When I started using a hot-plate to pre-heat my moulds, I just set a cheap Craftsman meter beside it with a k-type thermocouple plugged into it, and stuck the hot junction of the TC into one of the cavities so it touched the bottom of the cavity. I don't even know if it is accurate, but when it reads 386F, the mould will cast good bullets on the first pour, if everything else in OK.

If you have even a cheap meter with a TC jack, you can measure and record the optimum temp of your mould. It does not have to be accurate, or calibrated, or even agree with the TC in your pot, because it's RELATIVE. If YOUR cheap meter and TC reads 392F when it casts well, then 392F is YOUR optimum.

It's a cheap and easy way to achieve good results without spending a bunch of money. Lots of people have cheap meters with a temp function. If one does NOT, they are easy to acquire and can be useful for sorting out other problems with the household system of sorting out issues with your vehicle, lawnmower, log-skidder, coffee pot, .....
 

Winelover

North Central Arkansas
Before the hot plate, it was a judiciously used propane torch for many many years. I still keep one within arms reach.
 

STIHL

Well-Known Member
Just wondering how a toaster oven would work to pre heat an Iron mould. :headscratch:
Turn on upper and lower burner, set to 400 degrees, stick the mold in with handle sticking out. set for 20 min. and ding, you are ready. Just a thought, figured since my casting and Powdering will be done right next to each other. Might just double purpose the toaster oven. As I have not bought a hot plate yet. Only cast from Iron twice and know not to dip them, so last time just heated over the pot then used a rose bud attachment and some map gas, real quick.(carefully)
I’ve been pondering this exact thing. My thought is make a steel plate with cutouts big enoug to get the handle through to make a front for the oven, and stick them in and let them bake for 30 minutes. I think it will work.