Two simple questions: Mihec 6 cavity mold.

[Leadmelter]

I planning a casting session with my new Mihec 6 cavity 45/225 gr aluminum mold.
1. Can I preheat on a hot plate?
2. How hot should I run my pot?
I figure six cavities should keep the mold hot at a moderate rate of 3 dump per minute.
Thanks in advance!
Leadmelter
MI

[snuffy]

:confused::veryconfu

Mihec makes a 6 cavity mold? Mihec makes molds from aluminum¿??¿

If it's anything like a Lee 6 banger, get the mold hot on your hotplate, about medium should do it. As for the alloy, I'd not go above 750 degrees.

[captaint]

I have an old (er) Mihec 6 cav H&G 68 clone mold. Very nice mold - because it makes very nice boolits. I would not go nuts on the hot plate pre heat. I keep my cheapie hot plate turned up to about 2/3 or so. A 6 cav mold (aluminum) making 200 gr boolits won't be hard to keep hot once it's up to temp. It would probably be a good idea to use the NOE instructions prior to using a new aluminum mold. Initial break in, if you will. Always worked for me. I, personally, don't like to go over 725 for any mold. Often for AL, that temp is necessary. I often keep turning down my pot temp until the boolits don't want to drop from the mold. Then bump it up a little. Mike

[Down South]

:confused::veryconfu

Mihec makes a 6 cavity mold? Mihec makes molds from aluminum¿??¿

If it's anything like a Lee 6 banger, get the mold hot on your hotplate, about medium should do it. As for the alloy, I'd not go above 750 degrees.

This is the thread that the mould came from that the OP is discussing.

http://castboolits.gunloads.com/showthread.php?151445-MiHec-2-or-4-cavity-brass-45-RCBS-Cramer-HP/page8

I have at least one aluminum MiHec mould from yrs gone by. Don't remember what it is.

To answer the OP's questions, you can preheat the mould or not. It doesn't take many casts to get an aluminum mould up to temp.
Casting cycle will depend on circumstances. When the sprue puddle solidifies, you can cut the sprue and dump the mould. On casting temp, I normally start out a bit high around 775 and work my temperature down as the mould heats up and appearance of the boolits.
I guess the best way to say it is, let your mould and your alloy tell you what temp you need to cast at.

[snuffy]

Thanks Sam, I learned something today, the day's not lost! That looks like a real nice mold, looks like and probably casts like the lee 200 RNFP mold that I have. It;s a real good boolit!

[JonB_in_Glencoe]

Since this is a NEW mold.
I'd carefully preheat it.
My hotplate gets most molds hot enough on the LOW setting.
If you get the mold too hot, you risk warping it, especially a
longer mold like a 6 cav.

ALSO with a larger boolit like a 225gr 45 cal.
the mold will get up to temp fairly quick without preheating.
Good Luck,
Jon

[Dale53]

I have a couple of Mihec six cavity aluminum moulds. They are the same essential design as the Lee but made MANY times better (better alloy and far better tolerances).

I pre-heat all of my moulds (just above medium on MY hot plate). I strive to pre-heat just slightly below final casting temp bringing the mould up to casting temperature by one or two casts.

I also clean ANY and ALL new moulds with a toothbrush and Dawn dishwashing liquid and rinse in very hot water. The residual heat will dry the mould off (after patting dry with a paper towel). Then a pre-heat a down to business!

We are extremely lucky to have such mould suppliers as Mihec, NOE, and Accurate available to us.

FWIW
Dale53

[mroliver77]

I second dales directions and comment.

I have mihecs version of the H&G #68 in 6 cav aluminum. It drops them so fast it is amazing! My shooting pal and I work together when running it as we both shoot them. One casts while the other lines up ingots to preheat the. A second pot is premelting as you can go through 20 lbs very fast. We trade off without missing a beat. His 7 year old son has been getting in on the act now and we can run 100lbs of these in no time!

Running the melt as cool as it will cast well keeps mold from overheating. IF it is hot and mold wants to run hot we use the wet cloth in a pan of water ala Bruce B. to get rid of extra heat fast.

[DLCTEX]

I also preheat my 6 cav. Mihec 68 clone on a hot plate set on medium, I keep it in firm contact with the plate by setting a 1 lb. ingot on it. With the pot at 675* I get keeper boolits first cast. I highly recommend Bullplate lube on the mould and sprueplate, no smoke or other crutches.

[Bigslug]

Other than setting it on top of the pot to warm, I wouldn't bother pre-heating an aluminum solid slug mold prior to casting, but I would follow NOE's advice of cycling them up to temperature 3-4 times before casting to settle the pins. I do this by simply putting the assembled mold - sans handles - in a 375 degree oven for half an hour, allow to fully air cool, and repeat.

But my NOE and Accurate aluminum solid boolit molds start casting pretty slugs by about the 4th or 5th pour - so I tend to regard the hot plate (at least for these) as one extra piece of junk that's in the way. I'm learning that hollow points and bases, however, are a bit of a PITA to get up to temp - so I may break out the hot plate (purchased for lube making), the next time HP's are on the menu.

I've also slowed my casting cadence down a little for molds in this general class. I'd guess I'm running about 1.75 pours per minute. This seems to let the sprue harden up a little more and cuts down on lead streaks across the bottom of the plate.

[quasi]

I do not have a hotplate, I just dip my moulds in the melt until the Bullplate lube on the sprue plate starts smoking. It works great for me and thank you Longbow for the tip. Miha's 6 cavity's are great, I think I have 4 now.

[gimling]

am I doin something wrong? I have to keep my hotplate on HIGH, then dip the mold for almost 2 min, if I let it sit for more than about 30 seconds for a break for my hands I get crumple marks in my bullets/

also I keep my lead HOT, I teeter between too HOT, and some of the bullets split from being to hot,

[Leadmelter]

I got up early today and fired up the pot and put the mold on top. About 45 mnutes later I started casting.
What I learned:
1. Getting the mold hot took a bit longer than I thought.
2. I went thru about 1/3 of the pot with two good boolits.
3. I turned up the heat and carefully poured each cavity and things got better.
4. In the end, I have about three hundred boolits,a broke- in mold, and good reason not to cast in the summer.
5. By the way, a six gang mold can empty a RCBS pot in about a hour.
Good luck
Gerry
MI

[DLCTEX]

am I doin something wrong? I have to keep my hotplate on HIGH, then dip the mold for almost 2 min, if I let it sit for more than about 30 seconds for a break for my hands I get crumple marks in my bullets/

also I keep my lead HOT, I teeter between too HOT, and some of the bullets split from being to hot,

You may be casting too slow. The Bullplate lube lets me cut the sprue early with no smearing and I cast fast without stopping to look at boolits, keeping the mould hot enough to require slowing the pace to let things cool some.

[Down South]

You may be casting too slow. The Bullplate lube lets me cut the sprue early with no smearing and I cast fast without stopping to look at boolits, keeping the mould hot enough to require slowing the pace to let things cool some.

If you are slowing down to examine the boolits, your mould is cooling down between casts. I only examine boolits every once and a while waiting on the sprue to cool enough to cut.