Lyman Mold Question

[DDJ]

This might seem like a trivial or stupid question but how do you guys pre-heat your Lyman Molds? I've only used Lee Molds and a few casts and your ready to go. But now I need a new mold and Lyman is about the only company that seems to have the mold I need and its a fairly heavy 2 cavity steel mold. I haven't ordered the mold yet but I'm about to. Thanks
Dave

[Hickory]

The common practice is to use a hot plate, which I do.
But, for 30 something years I use to heat it up on the top of the pot.

[pworley1]

+1 on using the top of the pot. By the time the pot is ready so is the mold. The new mold will take a little longer to get to casting good bullets but after the first time it will probably start dropping good bullets after only one or to casts. Good luck.

[Rapidrob]

#2 top of the pot.

[JonB_in_Glencoe]

Preheating a mold on a Hotplate:
That was one of the best hint/tip/tricks to casting that I learned here at CB, and it made my casting sessions much more enjoyable.
Prior to me doing that, I only had marginal success trying to preheat a mold on top of my Lee pot or dipping the corner of the mold in the melt...it'd take me 20 minutes of casting to get good boolits with those tactics...20 minutes just wasted, plus the pounding on the sprue plate due to cold sprues, and all the mess of sprue chunks and particles and such in the dump area.

[georgerkahn]

Waaay back -- before I discovered the brilliance often offered on this site -- I'd rest my moulds on the edge of my Lyman MouldMaster to heat, along with the alloy heating to melt/flux/use. HOWEVER -- I learned (re this process ;) ) two things: 1st, I bought a real el cheapo hot plate, which I have a piece of aluminum on, and an inverted steel (also cheapo) flower pot with a "door" cut out for putting in/taking out the mould. Using the hot plate with the "garage" atop it has been an awesome improvement for my casting. I will note that my moulds are pretty much all iron, as your Lyman -- or, brass. (I only have a couple of aluminum.) I keep the knob set for about 2/3rds up on General Electric hot-plate -- and, again, it has been an awesome improvement. (And, too, a safety "plus" with worry about knocking mould off gone).
BEST!
geo254065

[stubert]

I also use a hot plate, I took an old fine tooth circular saw blade, ground off the teeth and set it on the heating element. It heats more evenly and you don't have to do a balancing act with the heating coils. I also took a 3 lb. coffee can, cut a small opening in the side and set it over the top.

[Phlier]

I also use a hot plate, I took an old fine tooth circular saw blade, ground off the teeth and set it on the heating element. It heats more evenly and you don't have to do a balancing act with the heating coils.

Exactly what I did, and it works great. At some point, I'll put a PID on the hotplate so I can fine tune the temp of the mold.

[gwpercle]

I have been sitting them on top of the pot , blocks on rim , wood handles supported by a block of
wood . If I want to speed it up I'll take a cue from Lee and dip a corner in the melt...works for iron moulds too . 6 cavity moulds benefit from hot plate heating but two, three and four cavity moulds don't really require a hot plate . I don't have enough circuits to plug in both a Lee Magnum Melter and a hot plate... when both go on the breaker trips .. so I just keep on doing what I been doing for the last 40+ years , pot top heating and two cavity moulds .
Gary

[Shepherd2]

My Lyman Mag 20 pot has a small shelf attached to the back rim of the pot. I set the mould there when I turn on the pot. I always have to block the handles up to keep the mould flat on the shelf. Normally by the time the alloy is melted the mould is good and hot. If not after a few casts it up to temp.

[Green Frog]

Another vote for setting the mould on top of the pot. The pot is there and heating itself anyway, why add to the process when you have a built-in preheater right there. As my old shop teacher used to say, “KISS - keep it simple, stupid!”

Froggie

[Mike W1]

My Lee 10# didn't have a shelf for warming so made one for it long ago out of aluminum. Year or two back I bought a hot plate. I'd never had any luck with a few of the Lee molds over the years but had one I'd bought mainly to cast samples for BHN testing. So I heated up the mold on the hot plate and was immediately rewarded with good samples from 1st cast. It really just confirmed what I'd thought after using the hot plate on the Lymans I normally cast with.

After numerous time measuring mold temperatures when using those Lymans and weighing bullets in order I KNOW the first bullets out will be good ones. Never quite got there using only the warming shelf. The maximum temperature I ever recorded with the warming shelf was 305°F. With my hot plate that happens to be PID controlled and set at 400°F that hovers at 398° the molds are around say 20-40° hotter than they'd be off that shelf. Would take several casts to warm the mold enough to get it to operating temperature. Believe the tip to use the hot plate and the accumulation of PID stuff have been the most valuable things I've learned about on his forum.

[DDJ]

Another vote for setting the mould on top of the pot. The pot is there and heating itself anyway, why add to the process when you have a built-in preheater right there. As my old shop teacher used to say, “KISS - keep it simple, stupid!”

Froggie

That's what I do with my Lee molds but I understand that the steel and iron molds take longer to heat up

[OS OK]

Try to find a hot plate that is 1,200 Watts if you can, you'll have plenty of heat. If it has coils, put a skill saw blade on there to heat the mould more evenly and an old can on top helps to keep the heat in to warm that sprue plate. That is a BBQ thermometer, perfect for monitoring the oven.


https://i.imgur.com/iS7OqX0.jpg?1

When this one hits 350º and that mould is pre-warmed it'll cast good boolits on the first cast, no kidding. A nice side to the oven is that if you want to take a break, put the mould back in the oven and you'll be good to go when you return.
With my wide door I can place two moulds there.

[dale2242]

I use a hotplate...dale

[Rich/WIS]

The old Lyman and Saeco 10# pots had a shelf and I used that but when I replaced them with a 20# Lee broke down and bought a solid surface hotplate at W-mart for about $20. Used the base from the tin that Danish Butter Cookies came in to make a cover, cutting a notch out of the side to clear the mold handles and added a wire bail handle. Once you work out the preheat setting for the plate you will not look back unless to ask yourself "Why didn't I do this sooner".

[Mike W1]

My experience after a lot of temperature taking is that tin can with a dial thermometer is wasted time and effort. Unless you're outside in a breeze as I didn't do that. I even insulated mine and same heating times,with or without the "oven". Heat rises.

[smoked turkey]

I have cast boolits for many years and basically just started with a cool mould and let the hot lead warm it up. This most often resulted in a long warm-up session before getting good wrinkle free boolits with a good mould fill out. I found a bargin priced coffee warmer at a thrift store and it didn't get the mould hot enough. This past Christmas, my granddaughter got me a hot plate for prewarming moulds and I have only used it once. However I will say it was a good addition to my casting session because I got zero defects and 100% of my boolits cast were keepers. Not bad for my first time with a hot plate!

[DHDeal]

I first read about the hotplate trick here. Bought a cheap one, put a saw blade on it and went to casting. Usually my MP brass molds will drop perfect bullets on the second or third pour. Before, it would be ten or so before the molds were hot enough.

I've since bought a better quality hotplate with a built in pid, had a friend cut me a piece of 1/4" thick steel that fits the hotplate surface and have even seen where my first pour drops keepers.

It seems most posting to this topic use bottom pour pots, but I'm a big cast iron pot ladle caster. The same friend mentioned turned a turkey cooker into a perfect height casting table with a top that holds all of the necessary stuff. Life is good....

[Jruby38]

Just dip the mold in the pot. Boolits come out nice and frosty so powder coat is better.

[kevin c]

...I bought a real el cheapo hot plate, which I have a piece of aluminum on...
geo254065

George, that is...ah...a really BIG piece of aluminum...

I'd guess it takes a good while to warm up, but, once it does, it probably gets your molds nice and toasty.

I use a hot plate too, for my aluminum 8 cav molds. I've been just putting the mold right onto the coil element. Maybe I'm risking damage to the blocks?

[Phlier]

George, that is...ah...a really BIG piece of aluminum...

I'd guess it takes a good while to warm up, but, once it does, it probably gets your molds nice and toasty.

I use a hot plate too, for my aluminum 8 cav molds. I've been just putting the mold right onto the coil element. Maybe I'm risking damage to the blocks?
Yes, you are. I've warped two aluminum molds beyond use by doing that.

[725]

A variation on the hot plate. I made a three sided - 1 inch stock steel - device that sits on top of my burner. The "legs" of the rack extend beyond the size on my burner, but the triangle thus formed is small enough to hold all my cast iron pots centered, steady & vertical over the burner. Then I crafted a six sided steel (with three slots to marry up to the three legs sticking out) windscreen to sit upon the rack. The windscreen also has a flat steel table top with a hole cut out to fit my pots. Think of a top hat with a hole in the top. Allows my melt to warm quickly and makes a table to set my molds on so they warm up.

I'd had it with my pot wiggling off center and occasionally slipping off vertical. This solved that. Adjusting a wobbly pot full of molten lead was just too much excitement for me. Now I have windscreen tall enough to come to the top edge of my pot and a useable surface to rest my molds on.

[kevin c]

Yes, you are. I've warped two aluminum molds beyond use by doing that.
Thanks for relating the first hand experience. I guess I've just been lucky so far. Rotary saw blade or other metal plate it shall be.

[oger]

A garage sale toaster oven they last forever and have always worked very well for me.

[Phlier]

Thanks for relating the first hand experience. I guess I've just been lucky so far. Rotary saw blade or other metal plate it shall be.

Yup, you'd think I would've learned after the first one. ;)

[georgerkahn]

George, that is...ah...a really BIG piece of aluminum...

I'd guess it takes a good while to warm up, but, once it does, it probably gets your molds nice and toasty.

I use a hot plate too, for my aluminum 8 cav molds. I've been just putting the mold right onto the coil element. Maybe I'm risking damage to the blocks?

What you do not see, is I have a hole drilled in the aluminum in which I have a PID thermocouple which (I use PID for several different operations) slides in when casting, to keep aluminum block at ~350*F. Bion, I was at a local junk yard seeking lead some years back, and I spied this aluminum disk. There is an ALCOA plant ~35 from said yard, and I thought there may have been a connection? I don't recall amount paid, other than it was much higher (by the pound) than I had anticipated -- but, in retrospect, have no regrets. Not in picture is an inverted metal can with a "mould doorway" cut into it which sits atop the aluminum, which further keeps moulds -- I like to use two different moulds, casting in tandem -- at "right" temperature.
geo

[Mike W1]

My aluminum plate is about 1/4" thick so I bolted a small piece that's drilled and tapped for the type TC shown to it. Nice even heat across the surface.

254853

254854

[midnight]

I went the hotplate saw blade route too. It worked well for a while but soon the saw blade warped a lot and no longer gave a flat surface to rest the mold on. I got a 7 in dia, 1/2 in thick piece of aluminum, similar to Georger's, & it works perfectly so far. No warping. I may make a "garage " for it. My brass molds need to run about 350+ degrees, no way placing them on the pot will get them that hot.
I use a temp probe in the mold to monitor mold temp.
Bob

[kevin c]

I can see a visit in the near future to a scrap metal dealer for a piece of aluminum plate...

Another theme I'm picking up on is digital monitoring and/or control. I've got that for the alloy (feeder and casting pots), and have been thinking about it for coating, but hadn't considered it for mold heating and monitoring.

Amazing the technology available for our humble little hobby. Lots of potential for scientific controls to improve production and quality. It may not always be necessary, but it's nice to consider the possibilities.

[greenjoytj]

I have been using a hot plate just like the one shown in post #14, thank you.

Now I am going to take some measurements and source a piece of aluminum plate and a cheap Walmart pot to make the cavity for a warming oven. BBQ oven thermometer too.
The PID is beyond my skill level but I do own the portable Lyman PID temperature measurement tool. The Lyman tool works good BUT you can’t leave the sensor in the lead (heat) for more than a ~ 1 minute because the heat will travel up an soften then melt the plastic connector junction between metal sensor wand and electrical wire to the hand held unit.

[kevin c]

I got a saw blade now. We'll see if it warps (maybe flip it over regularly, or turn off the heat when the mold is up to temp?). Anyway, better the blade than the mold.

[Martin Luber]

If my mould isn't casting well, I run a propane torch flame between the blocks for a few seconds