First Mold ever how to set it up

[CaliContractor]

Hello Folks,

I just got my first ever mold in the mail today. It's a MiHec brass 4 cav 452374 mold. I am a litttle confused after much reading on how to properly set this mold up. I see some say just heat cycle it and others are doing chemical treatments to them.

This is my first but not last mold and I want to set it up right so that I can avoid as many issues as possible down the road. I have a very accurate pid controlled oven that stays within 1 degree of my setting. When I do the mold blocks themselves what should I do to the HP pins??

Thanks,
Pete

[wlc]

I'm no expert by far but here is what I do with my MiHa molds. I wash them with dawn dish detergent and really hot water, scrubbing them with a toothbrush (the wife hasn't complained hers tasted funny yet :):) ). Then I just set them on my hot plate to preheat while the pot is coming up to temp. When everything is ready I pour a set of boolits and dump them if the bases aren't filled out. If filled out then I take a q-tip with just a drop of bullplate sprue lube on it and after cutting the sprue off I wipe the top of the blocks and under the sprue plate trying to avoid getting lube on top of the boolits in the mold. Then take the clean side of the q-tip and wipe it off. Then I open the mold and dump the boolits and repeat the sprue lube process on the alignment pins. It takes less than a dab and don't get any sprue lube in the cavities or you will be starting the process all over or have to cast a bunch of times to get the boolits to come out righty. MiHa's brass molds like to run hot and if your temps are good they will literally fall out of the mold with little if any tapping on the hinge pin.

That's my method and experience anyway. Hope it helps.

[JonB_in_Glencoe]

Most molds, I just clean and start using.
BUT,
I've learned the hard way that a Brass mold should have a little Patina on it. As much as that freshly machined Brass is soooo pretty. It'll cast better if it gets a little burnished patina on it...especially on the insides. I'd recommend Heat cycing your new mold after you clean it real well. Bring it up to casting temp...about 375 or 400 degrees, then let it cool...repeat that 3 or 4 times.

Others will chime in, that it's not necessary, and everyone has a right to there opinion, I've given you mine.

This is great thread if you haven't already found it...See post 12 for my photo of what can happen to a pretty brass mold with no patina.
http://castboolits.gunloads.com/showthread.php?169575-Brass-Patina-Recipe&highlight=Patina

[MtGun44]

"chemical treatments"???????????? Yikes. Never heard of chemical treatments, and
would avoid them like the plague.

Bare naked metal in the cavities is the best. Clean with dishwashing soap and hot
water. If there are still issues after the first use with fill out, venting or boolits sticking
in cavities, scrub with Comet and a toothbrush to super clean and lightly deburr.

Bill

[JonB_in_Glencoe]

I wasn't suggesting chemical treatments, I suggested heat cycling.
I posted the link for reference about the problem of "tinning" of a new brass mold and a Photo of my "tinned" mold.

In fact, guess what I said in Post 45 of that thread ?
http://castboolits.gunloads.com/showthread.php?169575-Brass-Patina-Recipe&p=2017241&viewfull=1#post2017241

[CaliContractor]

Here is what I did. I used the hot water out of the facet with some dawn dish soap and scrubbed it with a tooth brush for a few minutes. I then boiled it in a sauce pan and about 10 drops of dawn liquid soap. I dried it off and then stuck it in the oven at 400 for 30 min and let it cool. I have done this 5 times now and the color has changed from a nice bright gold color to a more dirty straw color.

What should I do with the pins?? same heat treat cycle or can i just clean those with denatured alcohol i don't think I was the threads getting wet a rusty?

[tomme boy]

I heat cycle mine 4 times then I smoke the cavities for the first use. i do a quick 150 bullet run and then let it cool back off. The bullets are then put back into the pot. The next day I use it as normal. Only had one mold that would not drop the bullets with just a light tap. That was more of a design issue than the manufacture of the mold. Too bad too. It just needed a little tweaking for the design and it would have been a perfect fit for my chamber.

[osteodoc08]

I usually wash with dawn and hot water. Stick on hot plate a few minutes. Let cool off. Heat cycle a few times. Then start casting.

With my iron molds, I'll spray them down with kroil when I'm done to keep them from rusting. Hose em off with brake cleaner when ready to cast.

The heat cycles patina the brass and all mine are a rich straw color.

I do the same with my aluminum.

I will place a small dab of BullPlate lube when I start and wipe with a q tip avoiding the cavities.

Never strike your mold. Ever. A tap of the sprue plate should be all that's needed to cut the sprue. If the boolits are sticking, something is wrong. With a new mold, I'll cast quite a few and not bother evaluating them as they will likely not be perfect. Keep casting. They'll get there.

[cbrick]

I clean mine with denatured alcohol & a tooth brush, set in mold oven on a hot plate while the pot heats up. Once the mold is at about 400 I put Bull Plate on the top of the blocks & underside of the sprue plate. Lube the shafts of the pins & install them, lube the alignment pins & start casting. No heat cycling, no smoking cavities, no kitchen sink, no mold blocks that look like post #12 in posted link.

How well does this work? See my avatar, that boolit is from a brand new MP 45 270 SAA and to this day it casts boolits that look just like that.

Rick

EDIT to add: Clean the disassembled pins with the same denatured alcohol & be sure to put Bull Plate on them & the threads because you just removed all oil when cleaning them, leave the shafts about 1/4 turn or so loose in the pins. Do not put oil on the pins.

[cbrick]

"chemical treatments"???????????? Yikes. Never heard of chemical treatments, and
would avoid them like the plague. Bill

The plague would be preferable. I read that thread a while back & it sent shivers up my back. It's well beyond me why anyone would think that such a fine mold would need such a thing done to it. It's no wonder I don't loan out molds.

Rick