5Cavity Mold Struggles

[Master_Mechanic]

Hi all,
First off I'd like to say I have a few NOE Molds and the workmanship is to notch and I love the bullet styles. My struggles are with the 5 cavity molds (aluminum) I have troubles getting wrinkle free boolits, I believe it to be too cold of mold. But the other struggle I have is that the sprue plate is very hard opening, it swings free when no lead is in it but its a tough cut when its poured full. Is this normal with higher capacity molds?

[dilly]

It's somewhat normal but it also has to do with the temperature of your mold. Do you have a hot plate to really get that mold preheated?
Do you stick a corner of the mold into the melt to warm it up?

When a mold is running nice and hot, you can see the sprue plate kind of "frost up." Generally you can cut a pretty soft, clean sprue immediately after it frosts. If the mold is too cold then this happens as you're pouring and it's pretty hard by the time you get to cutting it.

I think the long and the short of it is that you'll probably have more success with more heat.

[bhn22]

You are correct. Your mould is too cold. Also, did you follow the temp cycling instructions that came with the mould? Five cavity moulds naturally have more resistance at the sprue plate than smaller moulds, but the issues you're reporting all point to too low of a mould temp, and possibly too low of an alloy temp. High capacity aluminum moulds thrive on heat, and usually require higher temps to function effectively.

[Master_Mechanic]

I normally use my hotplate, however I have the new lyman digital furnace with warming shelf. I tried the warming shelf to preheat the hold and it clearly didn't get hot enough to drop good boolits. I did try higher alloy temp but again not good results, I will try again with my hotplate and hotter mold. Thanks for the feedback, I will report my findings.

[country gent]

You didnt state what alloy or tem it is at either. Multi cavity molds can take a learning curve as to casting withthe temp of mould alloy speed of casts ect ect. One trick is to cast one or 2 cavites for a few casts bring them up to temp then add a cavity or 2 then the last bringing the mould up to temp is stages. Also pouring a larger sprue at the start covering the sprue plate as much as possible helps some also getting up to temp. The alloytemp the mould wants is also important, long skinny bullets may take a higher temp to keep molten longer while pouring. A hot plate with cover helps alot getting mould pre heated, but you need to also know where "pre heated" temp is at also. A good lead thermometer helps alot with these issues. I have one mould that will cast very good bullets as low as 650* on alloy temp but cadence has to be pretty fast. Most want 700*-750* on alloy temps and cast at a cadence that maintains mould temp.

[Master_Mechanic]

Alloy was coww, temp was 700 on the digital readout. tried 730 and 750. didn't get much for results. but I will try the hotplate next time.

[NoAngel]

Every one is different and I have no doubt someone will be along shortly to berate me but I've found molds with cavities numbering more than 2 or 3 to be more hassle than they are worth. I can make almost as many in a reasonable amount of time with good consistency [and fewer culls] using a two cavity. The trick for me is to plan ahead. If I take a couple of percocets I can get a good rhythm going and juggle as many as (3) two cavity aluminum molds. I have a padded tray that's partitioned so I don't have to sort. No fear of opening a mold too soon. Run the pot about 750-775 and get digging. At the end of it, I have a big pile. Maybe not as big a pile at one time, but after several sessions, having coffee cans full of the various bullets I use regularly, sitting there waiting on me is nice. Also lets them age, casting them way ahead a time.

I've had several 4 and 6 cavity molds and with the exception of a Hensely and Gibbs I had once, they've all proved to be more trouble than they were worth to me.

Obviously, your mileage will vary.


BTW, If I had my druthers, I like old Ideal and lyman single cavity for bullets I put a premium on consistency.

[tazman]

I have a couple of NOE 5 cavity molds. I have found they need to be hot in order to work their best.
I don't have a hot plate. I heat them up on my gas stove using a low flame for about 5 minutes before I start casting. Usually the mold is a little too warm as it takes the sprue longer than usual to solidify.
This is ok and self correcting. The mold quickly cools to working temperature, usually within 2 casts. After that it stays right where it needs to be temperature wise. I never need to fight a cold mold and waste time and effort trying to get it hot enough by casting with it. I get perfect boolits with the second cast(the first cast gives frosty, undersize boolits).
I start with my lead pot turned up on it's highest setting and turn it down to where I usually cast as soon as I start a run.
This system works for me quite well since I am currently casting only for my handguns. I may need to adjust things when I start casting for my rifles but that is a different deal.

[captaint]

MM - I would go back to the hotplate first. Try to keep your alloy @ 750 or under. That recommendation of starting by pouring only 2 cav's at first is a good one. Make, maybe 12 casts that way, then go to 3 cav's for a while, slowly getting the whole mold up to temp. The aluminum molds do like heat. Once you get up to temp, the sprues will cut easily by hand. Do watch for the alloy to flash over on top, then cut the sprue right then. You'll be fine, just takes a little practice, that's all. Don't be stopping to admire your work, just keep pouring. Let us know how it goes.

[fredj338]

Anytime you add sprus you increase the force needed to open the mold. I usually start casting in two front cavs only then two rear, then as the mold heats up, all 4-6. With alum, that doesn't take long.

[Springfield]

I have a hotplate but rarely use it. I mostly cast with LEE 6 cavs but have quite a few Accurate and NOE 4-5 cavity molds. I preheat my mould by dipping the bottom in the molten lead, usually about 680 deg, and know it is hot enough when the lead just wipes off the bottom. Then I start casting. If everything is right letting the sprue cool about 6 seconds works well to keep everything hot enough and running smoothly. Any longer and things tend to cool off and cause problems. This is for pistol bullets in the 180-250 grain range. Any heavier and the mould gets too hot and I run it under a fan to keep it cool enough to stick with the 6 second sprue hardening parameter. Using this method I can cast 8-900 bullets an hour with the 6 cav LEE's, a bit less with the 4-5 cavity NOE's. I cut all the non-LEE mould sprues with my gloved hand. If you find you need to whack the sprue then you are running too cold, IMHO.

[MarkP]

I have a 5 cav NOE - .245- 75 gr I need to preheat to 350+ and cast fast, my alloy is at 725 F.

[MT Gianni]

I have a 5 cav NOE - .245- 75 gr I need to preheat to 350+ and cast fast, my alloy is at 725 F.

Hole size comes into play as well. It takes faster pours or a rest on a hot plate to keep a 22-25 caliber mold up to temp than a 45 cal mold with more bullet mass and holding more heated lead.

[jason f]

noe 5 cavity 311 247gr.
lee 20 pounder with pid controller set at 735
hot plate with pid controller set at 450
thats what works best for me.

[jimofaz]

You did not say what caliber/weight of boolit you are having NOE 5-cav fillout problems with. Size matters. My NOE 4 - 5 cavity aluminum moulds seem to like to be run at least 50 degrees F hotter than most of my iron moulds. My smaller caliber NOE .224-70-RN requires a higher alloy heat setting than my NOE .311-247-FN mould does. There is a lot more mould mass left over to act as a heat sink with the .224 mould. Smaller caliber/weight bullets = higher mould heat input needed via a hotter alloy or maybe a faster casting cycle time. Play with your pot temps & casting cycle times & see what that gets you.

[oger]

I picked up a toaster oven at a yard sale just leave the handles stuck out of the open door and set it at 400deg. works pretty well for everything from alum molds to an 8 cavity H&G.

[Cherokee]

I use Lee 6 cv and Accurate 5 cv almost exclusively and cast at 725* with WW+2% tin. Molds are preheaed on a hot plate @ medium or a tic above. Most of the time I get great bullets from the first; if not that, then the second pour. I always fill all the cavities. YMMV but preheating the mold to casting temp is key.