Trouble casting with MP 227-65 mold

[doctorggg]

I received this brass 4 cavity mold yesterday. Scrubbed it with comet and dawn using a toothbrush. Sprayed with brake clean. Pre heated it on a hot plate. RCBS Pro Melt bottom pour pot filled with wheel weights, about 4 lbs linotype and plenty of tin. I tried casting at temperatures from 710* to 850*. Boolits would not release and were terribly wrinkled.

After casting about 200 boolits no improvement. Cooled the mold down. Recleaned with dawn and toothbrush and brake clean. Another 200 boolits and nothing worth saving. Preheated my RCBS 22-055-SP and proceeded to pour perfect boolits. Nothing wrong with lead mix. Took a Foredom using a cloth wheel and Flitz and polished inside of each cavity. Cast some more boolits with the MP mold. At least they would release without beating the handles.
Still wrinkled and no keepers. Tried slow feeding, fast feeding and even force feeding.
Nothing that wasn't wrinkled. Preheated the mold both sprue side down and sprue side up. Fluxed with pine sawdust. Tried pouring straight into each cavity with sprue plate open. Did this 3 times and probably would have had 10/12 keepers. Appears problem is with the sprue plate.

Anybody else having this problem? Suggestions? The boolits are wrinkled like the mix is too cold or the mold is too cold. Neither is the case. Thanks for the help.

[Jailer]

skip the break cleaner and just clean with soap and water. Hot soap and water.

Heat cycle the mold a few times before use. By heat cycle I mean heat it up completely and then let it cool completely.

After you've done that you'll find that you have to run your melt a bit hotter than normal and cast at a VERY brisk pace to keep heat in the mold. Those little boolits don't add much heat when casting so your pace has to be quite rapid to keep it up to temp. I find myself even cutting the sprue sooner than I normally would just so I can get some more hot metal in the mold to keep it casting well.

[aya]

I have just finished a casting session with a MP 32 acp mold. Pretty small bullets to!
I think your mold is not hot enough. I use an 2000w hotplate set at 4 on scale to 10.
I do six casts, replace on the hotplate, do a visual inspection on the 24 bullets, then repeating the procedure. The seventh cast ,without replacing on the hotplate, would stick in the mold! Casting this way, make the number of rejects close to none.

[Chicken Thief]

Brass will take quite a while to develop a patina in the cavities!
Brass needs more heat that iron to cast properly.

I have found that most moulds are like rifles and they are all a little different and cast best if treated properly. For the same amount of alloy a smaller mould will shed heat faster (mass to surface ratio) and thus cast good faster.

Iron is "slow"
Brass is "medicore"
Alu is "fast"

[doctorggg]

Gentlemen,

You are giving me some great advice. All help is appreciated. I have 2 other brass moulds but they are of larger caliber. I guess since I tried casting with this mold for about 5 hours I was totally frustrated.

[aya]

I think you would struggle to cast that mold hot! Tiny bullets and brass is a challenge.
I has always tought i could do without a hotplate, i haven't had one for the thirty years i have been into casting. Please dont ask how many hours i spent with that 32 acp mold, before i realized it is a must!
I should have bought that hotplate 30 years ago.

[cbrick]

Jailer has it. Don't look at it as pouring alloy . . . Your pouring heat and at 65 gr even though there's four of them your not pouring much heat. Nothing wrong with the sprue plate, it is a thick piece of steel and it just like the mould needs heat. Pour a very generous sprue puddle just for the sake of the extra heat your pouring. You not only need the mold up to proper casting temp but the sprue plate also. If the sprue plate is too cool it will be very tough to get filled out bases because the plate is drawing heat from the alloy before it can get to the mold.

You mentioned plenty of tin . . . Not if your running your pot at 850 degrees. Tin will oxidize rapidly at 750 degrees, the more past that and the faster the oxidation.

Rick

[runfiverun]

with situations like this i heat the mold up so it's so hot to start i have badly frosted boolits that don't want to solidify.
i then start casting like there's a horde at the door and i need them right now.

[williamwaco]

with situations like this i heat the mold up so it's so hot to start i have badly frosted boolits that don't want to solidify.
i then start casting like there's a horde at the door and i need them right now.

Ditto.


I have never used a brass mold but I think your mold is not hot enough.

Any mold, new or old, I set the temperature of the metal at 650 to 700 and cast as fast as I can without being reckless. Don't even look at the bullets. At some point the sprue will begin to stay liquid for up to 5 to 8 seconds. After 5 seconds, if you tilt the mold to the side the sprue should run off the mold like water.

At this point you should be getting severely frosted bullets but the wrinkles should be gone. If you still have wrinkles there is something in the cavity - probably oil.

Now slow down. Gradually reduce the casting pace until the sprue is still soft enough after a couple of seconds that you can open the sprue plate with a gloved hand or a push of your mallet ( not a whack )

At this point you should be getting good bullets. BUT some molds require you to do this and then let them cool and repeat the process up to three or four times.

After you get the mould "broken - in" you will start getting perfect bullets long before reaching this level of heat.



.

[doctorggg]

I would like to thank each gentleman that answered my plea for help. I took ideas from each guy.
I only cleaned with dawn and very hot water. I then used a q tip and denatured alcohol to clean each cavity. I preheated the molt very hot. I cast like a mad man and when the mold began to cool down I put it back on the hot plate. I spent yesterday just heat cycling the mold. Today I was able to cast 300 boolits and it appears they are all keepers. So needless to say this newbie needed your advice. I am once again a happy caster. This mold isn't the easiest to cast with but it produces some fine boolits. Be Blessed guys and thank yoou again. Gregory

[doctorggg]

Jailer, your advice to cut the sprue quicker than normal was a tremendous help. I now understand with the brass mold being cooler than the steel sprue plate you can cut the sprue early and still have clean cuts on the bases of the boolits. Since I am still slower than necessary this 1 tip let me cast several more times before I had to place the mold back on the hot plate. Thank you kindly.
Gregory

[Jailer]

Glad you got it working for you.

I haven't been casting all that long compared to quite a few of the others around here but there is one thing I've learned. Every mold has it's own "personality" and requires you to adjust your casting technique to adapt to each mold. You have to give it what it wants, not what you think it needs.

[MikeS]

When using a brass mould, using a mould lube like BullPlate is even more important. It allows you to cut the sprue MUCH sooner than you would otherwise consider, and not get lead streaks across the tops of the blocks. Also, I don't know why everyone says brass needs the lead to be hotter than other moulds. Maybe for cramer style HP moulds, but not so for solids. I have several MP moulds, and even more brass moulds (from NOE, AM, and even an old Yankee), and I routinely cast with them at 650F. Another thing that really helps is properly preheating the mould. Don't heat it just til it gets to temp, then start casting with it, but let it sit on the hotplate for a while at temp to let the blocks get the heat soaked into them.

[doctorggg]

When using a brass mould, using a mould lube like BullPlate is even more important. It allows you to cut the sprue MUCH sooner than you would otherwise consider, and not get lead streaks across the tops of the blocks. Also, I don't know why everyone says brass needs the lead to be hotter than other moulds. Maybe for cramer style HP moulds, but not so for solids. I have several MP moulds, and even more brass moulds (from NOE, AM, and even an old Yankee), and I routinely cast with them at 650F. Another thing that really helps is properly preheating the mould. Don't heat it just til it gets to temp, then start casting with it, but let it sit on the hotplate for a while at temp to let the blocks get the heat soaked into them.

MikeS,

I presume you must be ladle pouring your lead. Both my RCBS and Lyman spouts freeze up if the lead isn't at least 720*. What am I missing?

Thanks,
Gregory

[doctorggg]

I am trying to cast at least every 15 seconds like one of the members suggested. I am using bullplate. I am running my lead around 780*. I preheat the mould until the lead will not even set up.
I think I am getting the rhythm down but my boolits are very frosty. Any problems with that? Other suggestions???

[MikeS]

No, I use a Lee bottom pour 20lb pot. As far as frosting, is it a slight frost, that you can wipe off with a rag (once the boolits are cool), or heavy frosting? A little bit of frosting is nothing to worry about, lots of frosting to the point where the boolits features are getting effected is not a good thing. The ultimate test is really how they shoot, rather than how they look. If they shoot ok, then the frosting doesn't matter. Don't know why your pots are freezing, they shouldn't. Perhaps you need to clean out the spout, lots of junk collecting around the spout could cause it to freeze up sooner than it should.

[doctorggg]

Both of these pots RCBS and Lyman are new this year. I got the Lyman first. It would only heat lead to 700*. The spout was frozen. I cleaned out all the oil so the pot was very clean. Had to call Lyman. They instructed me how to remove the knob and adjust the heater. Of course he was talking about temps around 900* which is way too hot. I removed the nozzle and drilled it slightly larger. No help. I just cleaned it out a couple days ago. Frustrated I bought the RCBS PRO MELT. Even when new it wouldn't pour until the temp reached 720*. I haven't cleaned it and that is something I will do. I have a Lee 20 pound pot. I will try it. Thanks for the info.

[MikeS]

Ok, one question I didn't ask you, how are you measuring your melt temp? It's quite possible that if you're using a thermometer that it's off. I have 2 identical thermometers that I use to see the temp of my moulds as they're preheating, today I was preheating a couple of lyman moulds, when I looked at them one said 300, the other said 400, so at first I thought perhaps one mould was on a cool spot (or the other on a hot spot), so first I moved the moulds around (I basically swapped positions), but that didn't change anything, the one was still 100F hotter than the other. Next I tried swapping moulds, but still the same one was 100F hotter than the other! So I've decided it's just a difference between thermometers. This brings me back to my point, if when your thermometer says 700F it's really 600F you could run into a problem of the spout freezing! So I would recommend that you buy another thermometer, and that way you can check one against the other. If you want to test your existing thermometer, and have some pure lead on hand, put the pure lead in your pot, and watch what temp it melts at. If your thermometer says it's melting at anything other than 621F than it's wrong.

[runfiverun]

good job on the splainin mike.
i am not a fan of frosty boolits, grey [galvanised with good definition is okay]
i use an alloy of 4% tin and 6% antimony to make my 22 boolits [and some of my 30 cal too]
i rarely use an alloy temp of over 725-f and am usually at 675-715-f throughout a run.
3 of my pots won't even go over 775*.

[MikeS]

Actually I like the term I've heard on here (possibly from Gear, I don't recall), calling it a satin finish. I try and cast all my boolits with that satin finish, still a bit shiny, but not like the shine you get when the mould is too cool.

[doctorggg]

I have a RCBS thermometer. I had a Lyman but Unfortunately I stepped on it. My boolits are a very light gray. No shine at all. But it will wipe off per one of your questions. I'm going to check the thermometer the way you said. I am going to cast some tomorrow. I try to observe the Sabbath.
After a year of casting I thought I had passed casting 101. However this small 4 cavity brass mold has humbled me. It is a great mold it is me that has to adapt and learn. I do thank you gentlemen for the invaluable advice. I'm sure other newbies are learning from this as well. All suggestions are appreciated.

[cbrick]

Hang in there Doc, your up against two brand new things at the same time. A brass mold and tiny bullets but it's nothing more than a learning curve. Won't be long and you'll be wondering what the problem could have been.

It could be worse, an aluminum mold looses heat even faster than brass and learning tiny bullets with aluminum can be frustrating.

Rick

[doctorggg]

That's the strangest thing. I started off with a NOE 225-62 5 cavity aluminum block and had zero problems even with the complicated MX3-22-EX design???

[doctorggg]

Rick,

I forgot to say thak you for the support. I'll be casting again this morning. I will master that mold with the help from all you good guys out there. I have read on several posts where this a friendly site with many people willing to help. I agree with that 100%. Gregory