Mold Temp Question

[Jim Flinchbaugh]

Having received my first NOE mold from a group buy I am very impressed with the quality. That said, in following the thread for the closed buy, it seems as if the best results are with a mold temp in the range 0f 380-420 degrees. How in the world do you get the mold that hot?
With big fat revolver slugs, the amount of lead in the mold heats it up plenty.
In this 2 holer, .311 diameter, there isn't enough lead mass to get the mold that hot.
If I run really fast, I can get it to the point where it will make a slight frosty surface before the front band, and I have to cool the sprue plate on a damp rag in order to chill the sprue quick enough to not loose heat in the mold.
This doesn't seem to jive with me for some reason. I know my mold temp isn't nearly as high as they say they are running them.
Also, I ladle pour, with a homemade ladle, with a spout, and I have to keep the spout tight in the sprue hole and slobber lead all over (think pressure cast) to get the base to fill out, another sign the mold is too cold I think.
I have pre-heated the mold on a hot plate, wont get that hot, aluminum gives up heat too fast. If I light the 2nd burner on the Coleman stove I cast with, and set the mold on the flame I can get it hot and get good fill out, but them I'm back to quenching the sprue plate on a cold wet rag. Is this gonna hurt anything?
Any input appreciated

[cbrick]

Get the mold pre-heated with a hot plate with an aluminum plate heat sink on it.

NOE molds have a great sprue plate, much thicker than what is considered normal. A sprue plate that is too cool will never give well filled out bases, the sprue plate has to be hot. It can be heated on the hot plate but pouring a very generous sprue puddle will both add heat to the plate and then keep it hot.

Rick

[btroj]

Some have made a small box from a metal junction box to keep the mould hotter.

The key is to find the balance point between melt temp, mould temp, and casting rhythm to keep mould hot enough yet not over heat it. That is tough with some moulds.

Cooling the sprue on a damp rag hurts nothing. Sometimes you gotta do what you gotta do.

[Jim Flinchbaugh]

Thanks guys.
I found that by getting the mold hot enough, without cooling the sprue plate, it took too long for the sprue to cool enough without smearing, and hence, the mold itself would cool off too much. I did find much better results doing this, and also I was having trouble getting the pour closest to the handle hinge to release the boolit on opening. The other one would jump right out. I did the lapping procedure with some toothpaste and shined it up, much better now. I was fooling around getting the boolit out before, that it was allowing the mold to cool too much. This baby likes it hot and fast!
The aluminum heatsink on the hot plate and the "cover box: is a great idea, I'll try it. I cast in ambient temps and right now that has been about 20* F.
I got 40 rounds loaded up and ready to see how this projectile flies!

[stubshaft]

If you are getting lead smearing on the sprue it's time for some Bullplate!

[1Shirt]

Agree with Stubshaft on the Bullplate. Also suggest that you may have your timing just a bit fast. Might want to slow down just a bit. It would appear that your hot enought.
1Shirt!:coffee:

[cajun shooter]

1Shirt is dead on your speed is too fast. You could also benefit from using Bullplate Sprue lube as it is the best casting lube made.
Everyone has a special way to cast and they all will work. Having said that I will give you my way. I have casted since 1970 and had a great mentor with years under his belt.
The best way that I have found is to use a good single burner Hot Plate. They may be purchased from Wallly World for about $20 or so. I also use two moulds and will explain why. I use brass moulds now but any material will work. By using one mould and a fast speed you will over work your mould and unless you allow some cool down time you could warp the blocks.
Turn on the hot plate to high and place both moulds on it to began heating at the same time your main pot is turned on. I use a RCBS PRO MELT and it takes about 20 minutes to come to pouring temperature of 750 degrees.
I take and fill the first mould and fill it and return it to the hot plate. I then do the same with the second mould. The next step is to go back and remove the first mould and strike the sprue plate and dump the bullets into a container. You will then refill it and place it back on the hot plate. Remove the second mould and do the same and always refill each mould before returning to hot plate.
This style of casting will make a lot of bullets fast and keep your moulds in perfect condition. I have no throw backs and make perfect bullets from the first pour.
Turn down your hot plate to about 50% the entire time of your casting and everything will stay at a even temperature. That's the entire secret is to maintain even temps. When a mould is filled and then placed on a bench, it loses heat that will cause the blocks to be too cold and then too hot which results in bullets that are not the same.

[MikeS]

I've never been able to get the hang of casting with more than one mould. What I do is to heat the mould on a hot plate (my old hot plate needed to be on HI, my new one needs to be on MED), once the lead in the pot is ready to go at casting temp (I cast at around 650) I take the mould off the hot plate, and start casting. I use a bottom pour pot, and I quickly fill it up, I don't close the spout between cavities, I just pour one, move to the next, etc. all with the spout open. Once the last cavity is filled I wait maybe 3-4 seconds, then just using my hand I open the sprue plate, dump the sprue back into the pot, then I open the mould, and let the boolits drop out. If a boolit sticks, then I will tap the hinge, but that rarely happens anymore (when I was first learning I had to use a mallet all the time, now the mallet is off to the side somewhere). I don't rush, but I'm not slow either. I cast using Lyman #2 alloy, and usually my boolits usually have a nice satiny finish, not quite frosted. I use either BullPlate, or the lube that comes with Mihec moulds interchangeably but I always make sure there's a coating of either on the tops of the mould blocks, and the bottom of the sprue plate, but you have to be sure and only put a very thin coating on, I usually put it on with a Q-Tip, and once it's on, I'll go over it with the other end of the Q-tip to make the coating very thin. I also lube the alignment pins with the Q-tip as well.

I just got a 5 cavity NOE aluminum 311316 mould, and I was concerned that the large chunk of aluminum with the little cavities wouldn't stay hot enough, but the other day I cast over 300 of them, and I had no problem at all keeping the mould temp up in the proper range (I say the proper range, as I really have no clue how hot the mould is) that I can cast, and open the mould with just my hand.

Don't forget that with aluminum moulds, sometimes you need to heat cycle them a few times before they start working at their best. I suppose this is true of iron and brass moulds, it's just that I've noticed it more with aluminum moulds, both high quality ones from NOE, and also with the not so high quality ones from Lee.

[geargnasher]

Having received my first NOE mold from a group buy I am very impressed with the quality. That said, in following the thread for the closed buy, it seems as if the best results are with a mold temp in the range 0f 380-420 degrees. That's my experience as well, generally I lean toward the 420 figure with clip-on wheel weight alloy plus 1% tin, that gets past the frost on the edges of the bands and up to the point that a lighter, even, satin frost forms over the whole boolit. Forget getting good boolits that are bright and shiny all over from a cooler mould unless you are a casting god with pid controllers and a mould thermocouple. How in the world do you get the mold that hot? I get mine hot enough to cast before casting by using a mould oven I build from an electrical box and a hotplate. You can cast forever with a ladle and never get that mould hot enough just by pouring lead into it. Once it's preheated to at least 400 degrees all the way through, which takes about 15-20 minutes in the mould oven, I cast very, very fast, about FOUR CYCLES PER MINUTE, to keep it hot enough to run. Pour a small sprue puddle and use the slighest hint of Bullplate film under the plate to prevent lead sticking. You should be able to cut the sprues by hand, don't allow them to cool enough to have to whack them with a mallet, that way you keep the pace up and don't lose too much heat from the blocks.

With big fat revolver slugs, the amount of lead in the mold heats it up plenty.
In this 2 holer, .311 diameter, there isn't enough lead mass to get the mold that hot. Four cycles a minute. You might need to use a bottom pour if you're not that fast with a ladle.
If I run really fast, I can get it to the point where it will make a slight frosty surface before the front band, and I have to cool the sprue plate on a damp rag in order to chill the sprue quick enough to not loose heat in the mold. That's not as hot as I like to run them, if you cast a bit faster you can get the frost to even out, and the dull edges of the bands disappear and get razor-sharp again once you get above the mould temperature where most of the boolit is shiny and just the edges are white and rounded.

This doesn't seem to jive with me for some reason. I know my mold temp isn't nearly as high as they say they are running them.
Also, I ladle pour, with a homemade ladle, with a spout, and I have to keep the spout tight in the sprue hole and slobber lead all over (think pressure cast) to get the base to fill out, another sign the mold is too cold I think. Actually, your sprue plate is probably too cold if you have to pressure-cast to get the base to fill out sharply, sprue plate temperature is key to getting a sharp edge. If too cold, or if you fill the mould too slowly, the base will be rounded. Allow the sprue plate to get hotter and see where that gets you.
I have pre-heated the mold on a hot plate, wont get that hot, aluminum gives up heat too fast. That's why I built a mould oven. Once it's really hot enough, you can keep it as hot as you need to by casting really fast. I've helped several people hands-on with mould fillout after discussing their troubles on the forum, and I can tell you that 100% of the time they didn't have a solid concept of just how fast you need to cast with no pauses in order to keep a small-caliber NOE (or Lee commercial six-cavity) mould hot enough for good fillout. Seriously, get an analog wall clock with a second hand and time yourself. Four cycles a minute is what my mould takes to stay at casting temperature with wheel weight alloy. If I light the 2nd burner on the Coleman stove I cast with, and set the mold on the flame I can get it hot and get good fill out, but them I'm back to quenching the sprue plate on a cold wet rag. Is this gonna hurt anything?
Any input appreciated

Quenching the sprue plate lightly on a wet rag won't hurt the mould if not overdone, but I think it's contributing to your problem of not being able to get the mould hot enough. I really don't think you've been overheating the sprue plate, in fact I think the opposite has been happening. A VERY thin film of Bullplate sprue lube will help prevent lead from smearing on the plate or the top of the blocks, and if you cut your sprues while they are still soft rather than waiting for them to harden completely it will help you keep your casting pace fast and the blocks/sprue plate hot enough for good fillout.

Keep in mind that this is my solution and techique with this particular type of mould, not the ONLY way that works. But it does work, and yields very consistent, accurate boolits if done right. You know the mould and sprue plate temperature is right (according to me!) if the light, satin frost on the cooled boolits wipes right off with dry rag leaving a shiny surface behind, and if there are small craters in the bases right under the sprue plate holes.

Gear

[Jim Flinchbaugh]

You know the mould and sprue plate temperature is right (according to me!) if the light, satin frost on the cooled boolits wipes right off with dry rag leaving a shiny surface behind, and if there are small craters in the bases right under the sprue plate holes.

Gear

This was my finding the frost wiped right off, nice sharp corners and a small crater. I should have described better, the lead wasn't really smearing, it was leaving the small crater, which I figured was bad for consistent bullet weight, and unimportant as far as the flat base cause that's what gas checks are for[smilie=l:

I have the sample of Bullplate that came with the mold, I like it very much. On other molds I've been using some of the stick stuff that came with my LBT molds, works, but messy and makes the molds ugly
I appreciate the input, it does work better each time I use it & as I get the hang of it.
Who would have thought that different blocks of aluminum could have different personalities, but they sure do!

[geargnasher]

It seems like every mould has it's own personality, and to make it even more difficult, changes in the weather make each casting session somewhat unique as well.

As far as the craters go, if you're dead-on consistent with your technique and timing, they will all be the same. If the temperature of the alloy, mould, or sprue plate changes, or if your timing gets sloppy, the craters will change in shape/size, so I think it's a great indicator of boolit quality. And no, they won't affect anything, even with plain-based boolits, as long as they're consistent.

Gear

[W.R.Buchanan]

Gear thanks for the insight. I've been having problems with my new NOE 311299 also.

I am running 750 + and get pretty much complete fillout every shot but some small wrinkles on the nose of the boolits. If I go hotter on the lead I get frosting that wipes off but still I'm having the wrinkles on the nose section. I don't want to go much hotter as I am on the verge of alloy separation as it is.

The mould is slightly above 400* and I know this because the alignment pins turned a nice pretty blue which is what happens at about 400-425F

Going faster is probably what will fix my problem. I spend too much time inspecting the product instead of making more and going faster. You just don't realize how fast the aluminum bleeds off heat.

Larry Gibson also suggested getting the mould up closer to the nozzle and dropping a small bit before dumping into the cavity. Right now I'm about 1/2-3/4" below the nozzle. I can move it up easily. This would result in a hotter material going into the mould also.

The short fat boolits are not a problem, and I am going to use my .45-425GC NOE mould tomarrow and I don't expect even one iota of problems with it,,, becasue the boolits are so big the mould stays really hot.

It's the long skinny ones that are a problem.

Just like with the Brass Mihec moulds there is a learning curve. I had problems getting that mould to work right also. But since we have "them that knows" to draw on, success can be achieved by many more people than ever before.

That said,,, Today I also ran a bunch in a newer 429215 mould I recently aquired . Out of 60 boolits I had 5 culls. But once again it is a short fat boolit, and it is easy to get a good product.

I have a 311299 Lyman mould that is "relatively easy" to get good boolits out of, but they are too small so it is a mute point. The NOE mould was bought to get "on size" and size wise they are right where I want with the nose end at .2998 and the driving bands at .311

Thanks in advance. Tommarow will yeild success!

Randy

[41 mag fan]

MikeS
We've discussed before in other posts, me and you cast alike in many ways and it seems to work good for both of us.

Gear.....

Very informative as is "The Norm" with your posts on casting.
I've read many and many posts where you've chimed in, and I have applied these techniques from your posts.
So far I've never been led astray.
Thanks Gear!

[Jim Flinchbaugh]

OK following the advice given in this thread, I built a small "mold oven" from a flat piece of aluminum plate with a sheet metal box around it. I will also try using a touch more bullplate on the sprue plate than I have been. I hoping to get time to cast with it tomorrow and see if I can get better. The last batch I did, came out really nice for my novice attempts.
Thanks again!

[MikeS]

Jim: I don't know how much BullPlate you've been using, but be careful that you don't over do it, a little is all you need. If you can see the coating, then it's too thick!

[Jim Flinchbaugh]

Well, never got around to casting today, but I did smelt out 175 pounds of shiny new ingots:bigsmyl2: