Trouble getting a clean cast. Please help.

[CoolHandMoss]

I have recently began casting for .45 acp, the biggest boolit I've cast so far. I got this new NOE nlg mold. The mold is clean, no detectable defects, and it is capable of dropping a clean bullet. I am having a problem though where a solid 30% of my bullets drop with some wrinkles. The attached picture is the most common appearance of the wrinkled bullets. I don't believe it's a temperature problem. This occurs even when the mold is so hot that the sprue crumbles when I cut it. I have tried pouring slower, I have played with pouring at an angle. I have added extra tin to see if that helped. All to no avail. It is my guess that this is caused by the lead cavitating in some way as it flows into the cavity. I would really like to get cleaner pours. I cannot find any distinction in procedure between the pours that produce smooth bullets and those that produce wrinkles. Any ideas?

[Fireball 57]

Sir: While there are more experienced casters in the background, might I suggest: 1. Check your melt for zinc and flux vigorously. 2. Thoroughly, clean your mold block and cavities removing oils then lubricate the pins. And, 3. Heat your melt to 700 + degrees. Good luck and have a good day! Fireball 57

[CoolHandMoss]

I have cleaned the mold a couple times now trying to get it to drop clean bullets. My lead is pretty clean, though maybe not the cleanest. I am doing up another batch tomorrow so I will be more careful about cleanliness.

As far as temperature, 700+ requires me to slow way down with this mold. I am generally below that on the pour temp but I have tried heating the pot to above 700 and I am still getting the same problem. Perhaps I do need to experiment more thoroughly with temperature though.

[Targa]

This occurs even when the mold is so hot that the sprue crumbles when I cut it.

This seems more of an issue with cutting the sprue to soon, let it harden a bit more. I see no signs of frosting in the picture you attached, my guess would be that although your lead is up to temperature your mold cavities are not. I would also try and run the lead in the 725 degree neighborhood.

[CoolHandMoss]

Hm. Perhaps I really do need to just crank the pot up and increase the pour temperature. Generally my natural rhythm dictates that if I have to wait more than 15 seconds before cutting the sprue then the pour is probably too hot. Perhaps I just need to crank it up and slow it down.

[Targa]

I meant to ask, is the mold aluminum or brass. The only reason I ask is that of all my molds, my brass ones are the biggest pain in the rear to get good pours, they take a bit of patience even after preheating on a hot plate but once they are at temp they are smooth as butter.
My aluminum molds are my favorite but can overheat quickly at my pace, once I get them rolling I cast until I get signs of frosting and then press the mold onto a wet sponge. I repeat this through my casting session.
In a nutshell, molds need to run hot...

[CoolHandMoss]

This is an aluminum mold.

I will try getting the pour good and hot tomorrow and seeing how that does. With my 9mm molds I generally find that if I am having to wait extra time to prevent my sprue from crumbling then it's too hot. Perhaps the .45 needs a little more heat to fill out.

[fredj338]

I sometimes pressure cast, pour spout tight against the spru plate, then form your puddle on top. Just something to try.

[CoolHandMoss]

That is something I have not done before. I will give that a try as well tomorrow.

[44Blam]

I have cleaned the mold a couple times now trying to get it to drop clean bullets. My lead is pretty clean, though maybe not the cleanest. I am doing up another batch tomorrow so I will be more careful about cleanliness.

As far as temperature, 700+ requires me to slow way down with this mold. I am generally below that on the pour temp but I have tried heating the pot to above 700 and I am still getting the same problem. Perhaps I do need to experiment more thoroughly with temperature though.

You would be surprised. I have a mold that I HAVE to cast at 725+ and heat it up until the boolits get frosty. Then maintain the pace. Each mold tends to be a little different.

[hermans]

I would start by pre heating the mold on a hot plate right up to casting temperature, even a little more is fine. Then the boolits should be well filled out but frosty. Ease off a little on your cadence until the boolits are just slightly frosted. For me, if my boolits are shiny they normally are not properly filled out, once the have a slight frost they are perfect!
My alloy is COWW of course, hope this helps.....

[Evoken]

Did you heat cycle the mold like Mr. Nelson and some members here suggest? I have found his molds do much better if you heat cycle several times in a toaster oven before ever casting with it. For me, it helps with my few noe molds.
Ken

[JoeJames]

Still new at this, but seems to be as much art as science in casting. I got in a new Lee aluminum mold a couple of months ago; first run was tolerable but just not perfect. The next time I tried it they were absolutely perfect. Not doing anything different the second time at all. Seasoning maybe.

[Land Owner]

From Glen Fryxell's on-line book (see Sticky From Ingot To Target) it is mentioned to assure the spru plate is sufficiently hot (as well as the mold) or the molten lead going through is cooled prior to reaching the bottom and sides of the mold, contributing to the making of wrinkles.

[OS OK]

That cast in the picture appears to be a gas problem. I believe you have oil in the cavity and it is gassing with the hot lead.
It also looks like you have an inclusion of oxidized tin.

This is not a very good picture to try to troubleshoot with...



I have collected many old moulds over the years and not knowing anything about them as far as their casting performance...the first thing I do is disassemble them down to the very last screw...place them in a pot of water with some Dawn (or any de-greasing dish soap) and boil them for about 15 minutes.
Three times I boil them, the first two is with the soap, the last boil is with fresh water only.



Pour the pot off so that the oils go over the edge before the water in the pot comes down to the mould & parts. You can do this by putting the pot under the faucet and flushing with fresh water as you pour it off.

Next put them in the oven at 400ºƒ and bake them for 30 minutes.



When you re-assemble, lube the threads of all the screws, the underside of the sprue plate at the hinge point & washer on top, the mating pins and their holes with 'Anti Seize'...it is a thick lubricant designed for extreme heat applications & most important...it will not migrate into a cavity.



Use sparingly. Notice that I put it on the forks of the mould handles where the mould rotates open & closed.

Insure that your sprue plate is flat, if needed sand the bottom side on some 300 grit paper or, whatever paper you have...the important part is to sand it on a flat surface.

Preheat your mould to upwards of 400ºƒ and set your pot to about 720ºƒ and you should be casting good keepers the first or second throw.



If you are aware of all this just disregard...I tend to go overboard talking about moulds and casting.

charlie

[ABJ]

In my experiences with NOE molds is after a good cleaning when new, it still takes several casting sessions of above 775 degrees to get good boolits. My sessions are not less than 250 boolits from a four or more cavity mold. I have never found a way around this. I usually cast a couple hundred the first time and increase by 100 each after that. I have had some molds through good on the third session and some takes a couple more. Some Lee molds are the same and some are not. Accurate molds will calm down after one good casting session most of the time.
Tony

[Sasquatch-1]

First off, is the wrinkle in the same spot every time? If so I find that this is usually a sign of grease or oil in the mold. I usually pour a few bullets with the sprue plate open and pour very slowly to allow the buildup to burn off. I usually get this problem when I use wax to lube the sprue pivot point.

If not try adding a little tin to the mix in the form of pewter or plumbing solder. It is my understanding that the tin helps break the surface tension.

[William Yanda]

Kudos to OS OK for a terrific post, with pictures of how he gets success.

[Cherokee]

Another thought, if the sprue plate is not hot enough, it will cool the lead before the cavity is filled.

[CoolHandMoss]

Yeah sorry, hard to get a good picture of something so small on my phone. The wrinkle isn't in the same spot every time but it is in pretty much the same position on the bullet every time.

When you check the temperature of a mold, do you just check the outside? Or the inside mating surface I guess is better? Today I want to make sure the mold is getting to 400.