About ready to give up on my MiHec 200gr...

[JesseCJC]

Be forewarned, they look sad and will make you laugh probably but I have tried every thing to get some boolits from this mould and failed. I have no problems with any aluminum mould I have, just this one which is my first brass.

I have tried dadgum near everything and I can not get this mould to drop anything worth noting to save my life. I have tried everything from 800+ temps, 20 minutes on a hot plate to bring the mould up to temp, switching pins, alloys, you name it and I am having the greatest trouble getting this mould to drop decent boolits. Granted, this mould could be too complex for this noob but i am seriously debating putting it up for trade for a LEE 6 cavity as it's of no use to me. What is the first and foremost problem boolit fill out. Main area obviously is the pins. The cavity cause by the pins will either be incomplete, wavy, or look collapsed. I will also get the stray that will have almost a hairline crack running in a spiral up the boolit itself.

Alloy has been straight clip on WW, WW/plumbers pipe, and WW+tin all have failed.
Mould was soaked in mineral spirits, pins coated with KROIL and cavities have been cleaned with a toothbrush all prior to getting started.
My process is this:

Warm up the hotplate with the mould on top on med/high setting on this hotplate
http://www.gehousewares.com/Browse_P...category_id=33
For about 20 minutes as the alloy gets to temp in the LEE 20lb drip-o-matic. I start off at setting 5 until it starts to melt (usually 1/2 full of alloy) and then crank up to 7 which is usually about 750ish maybe a little less. The spout is about 1/2in from the mould, pour, cut sprue dump rejects as usual and keep trucking. Not much rest between to keep the brass mould hot which is obviously MUCH hotter than I need to run aluminum which I learned to cast with. I understand that even with a pretty lengthy pre-heat I will have rejects in the form of wrinkles and what have you, no big deal. But when that 1/2 the pot goes down to 1/8th of a pot with not a keeper, I am at a loss for words.

These were the last ones to drop after 1/2-1/8 pot





You can see all around the cavities that it looks like they are sagging or even have a small crack. The rest of the boolit is fine but what good does that do me?

What am I doing wrong?

[AnthonyB]

Jesse:
I have had several mould who just needed to be taught who was boss, so don't give up yet. Looks like you still have some oil in the mould; try brake or carb cleaner before your next attempt.
Tony

[Maven]

What Anthony B. said, and try casting with a ladle. After cleaning the cavities and pin(s) again, smoke them with a few wooden matches when they're almost up to temperature. Are you using a casting thermometer, as I suspect your alloy may not be as hot as you'd like?

[fishnbob]

Jesse, I am waiting on my mold with bated breath. I only own aluminum molds. This my 1st venture into anything other than aluminum. I am scared s---less!
Allright guys, break out the brains & communicate!

[Heavy lead]

Try pressure casting, hold it right up tight to the spout and let it flow, count to 7 then drop in and lower it enough to make a good sprue, then go to the next cavity and repeat. I find if I do this a few times warming up a mould they go to pouring just fine after words not pressure casting.

[anachronism]

Start over, from the beginning. Clean & degrease the mould & pins like Maven suggested. Smoke your hollowpoint pins, preheat the mould & try casting at 800+ degrees. I usually preheat my hollowpoint moulds so that the first bullets are heavily frosted. When they freeze, I cut the sprue & toss both the sprue & bullets into the sprue pile. The second set of bullets will be less frosted, and the third set even less so. Cast quickly until the mould settles down & gives consistently good bullets, then I adjust my pace as needed. I think you just have a mould with oil in it, that you might be casting too slowly. Those aren't cracks you're seeing, they're wrinkles, and they're most commonly caused by oil in the mould or a mould that's too cool.

[JesseCJC]

I have a small thermometer I use in the pot and I keep it around 750-820 at max. When you say smoke the mould/ pins, can you elaborate a bit on that? Would something like brake clean be sufficient? Would I just let it dry out naturally or rise it off with water or what? Thanks

[Heavy lead]

IMO nothing works as good as dish detergent and almost (or boiling) water, then I further degrease after dry with denatured alcohol or brake cleaner.

[Digger]

Anachronism is on the money.... one more tidbit i have found with miha's molds is after preheating on the plate like a lot of us do , we also dip the mold into the pot to heat up more , mainly the pins .
Coming out frosted is the big clue and you work from there....up or down in dip time , once you have it , your rhythm comes into play from there.

digger

[Cord]

Others more knowledgeable than me will help, but here’s my .02 -

I would scrub the mould with denatured alcohol and a toothbrush
and then blast it clean with carb cleaner.
Put a bit of sprue lube or Kroil on the pin tips only after it’s hot.

Mostly, your mould and your melt do not appear hot enough to me,
because the metal is “freezing” and not “flowing” into the nose area.
If you have plumber’s pipe and tin, try a 20/1 or 25/1 alloy of those,
it may flow better into the cracks at high temperature.
25/1 flows good for me and will not frost at max temp on my RCBS.

Try to get both melt and mould as hot as you can until you start to get
“finning” around the pin tip and into the vent lines, then back off a bit.

IMHO, a brass mould needs to be almost as hot as your melt to keep
the metal fluid long enough to fill out the entire boolit cavity.

Joke On /
Glen Beck tells you the truth FAR more than your Drip-O-Matic will
/ Joke Off

.

[hoosierlogger]

When you say smoke the mould/ pins, can you elaborate a bit on that?

Open the mold and hold a burning kitchen match below the mold so that the smoke and soot settles in the mold cavity. Usually one match per cavity half. You should need 4 matches to do your mold.


You might want to check and make sure nothing is blocking the vent lines on the mold. That can lead to poor fill out.

[miestro_jerry]

I have many iron, steel and bronze molds from various times of my life. Aluminum ones are with in the last 5 years.

The one hollow point mold that I bought as a HP mold, I have to over heat it a little to make the lead flow thru out the mold.

My iron and steel molds, I keep them with dishwashing detergent, let them dry thoroughly, then smoke them with either wooden matches or an old fashion candle.

With some molds I cast with, I throw the first 20 or so castings back into the pot. Most of my molds have different personalities, many are very similar and others can be very different. When you have over 100 molds, remember which one acts which way can be difficult.

Here is a great resource for CB information: http://www.lasc.us/ArticleIndex.htm

Jerry

[pistolman44]

I have the same mold and it's the best mold I own. I degrease it with brake cleaner and use Bullplate sprue lube on sprue cutter and the sliding area of the pins and around the bottom of pins where the mold closes on them . Never put lube or anything on the top of the pins. Keep the hollow point part of the pins dry and hot. I use straight WW only. Once I get it up to tempt. I can go thru 18lbs. of lead in no time and all bullets are perfect. My next mold will be for the 41 mag from Mihec.

[MT Gianni]

Pm me if you want to swap for something. I think it's fixable given the solutions mentioned.

[BSkerj]

The only thing that I can add that has not been said above that I have done with mine is literally turn on my turkey / smelting flame and put the mold, opened up over the flame for about 5 min. I fill the mold and open the sprue plate to make sure the lead is still molten. I know that if I have to wait for the lead to harden up the mold is up to temp. Then I start pouring getting a few frosties and from there out great bullets.

[Edubya]

How about seeing what temp that you're hot plate is heating to. It seems that you're lacking heat in the mould and turn your pot up 'til you're getting frostys. You ain't gonna hurt the mould by getting everything hotter. Just stay cool yourself. If all of us can do it, you surely can!
EW

[Blammer]

What it sounds like to me is the pins are oily or dirty.

Clean it with carb cleaner, denatured alcohol, scrub in hot soapy water, what ever, just get that rascal really clean.

DON'T add ANY release agent to the pins or the cavity. (I would use a Qtip with my choice of mould lubricant for the hinge pin and locking pins) Make sure it is very clean. I'd preheat the mould, get my melt to my normal running temp and then use a lighter or match and smoke the pins, ONLY A VERY LITTLE! So much so that you'll likely not see it.

I'd then start casting.

My observations on your boolits is that you have some oil on the pins that is preventing fill out.

Get your mould and melt hot enough that you'll have to count to 5 to wait for the sprue to harden, then count another 15 and crack the spure and dump. Observe your boolits, if they are filled out well, then you can lower the temp gradually until you come to a comfortable casting routine for you.

[MT Chambers]

My guess is that the pins are cooling too much, in between pouring the next bullet, the pins have to stay around the same temp as the mold. I'm not familiar with that particular mold but even the Gould can do that until you get a good way to minimize cooling of the pin in between casts.

[mooman76]

I'm with MT Chambers. I think your pin is not hot enough and it is cooling the lead around the nose. Crank the heat up all the way until you get major frost like someone stated and slowly back down util you are putting out good bullets. Don't fidget with the mould while you are doing this as it will be cooling off. Just keep cranking out the bullets as fast as you can to get the mould and pin up to temp. If your pin is seperate from the mould make sure you heat it too.

[fredj338]

Try pressure casting, hold it right up tight to the spout and let it flow, count to 7 then drop in and lower it enough to make a good sprue, then go to the next cavity and repeat. I find if I do this a few times warming up a mould they go to pouring just fine after words not pressure casting.

This is exactly how I cast w/ all my HP molds & many others as well. Fill out is much better, yeah sometimes you get fins, but those flick off. Getting the bullets to release has been a bigger issue w/ my Mihec.