MP mold spru plate problem and solution

[uglysteve]

Hey I just wanted to share my recent issues with my .453 200gr swc mold and how I solved it with the hope that it may help some of you. My 4 cavity mold would pretty consistently drop the 4th bullet with some overflow under the spru plate which made its weight a little high and also made it difficult to size. The reason for this was a little bit of play in the spru plate. Even with the screw tightened very tight, I still got some play. http://img.tapatalk.com/d/13/11/07/y4a3a6y7.jpg It's hard to see, but some of the lead has spilled out under the spru plate.
86810
This happens with varying degrees but is pretty consistent. I resorted, for a while, to just filling three of the cavities. This kept me from getting a bad bullet, but I was unhappy. So I contacted Mihec who sent me another spru plate. Same problem. Although, now I have another spru plate screw and I had an idea...Why not use the screw to hold down the far end of the plate. I removed the roll pin and tapped the hole with a m6.0x1 tap (the thread pattern of the screw). Now I tightened the screw down to just the amount needed to hold the plate snug at the far end. Works perfectly.
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[GLL]

What is the dark brown "stuff" on the surface of the mold (under the sprue plate?

Jerry

[dragon813gt]

What is the dark brown "stuff" on the surface of the mold (under the sprue plate?

Jerry

Seriously, what have you done to the mold? A patina is one thing but that looks really bad. It's a picture so I could be completely wrong so no offense is intended.

[paul h]

I'm guessing a liberal application of Mihecs lube oil.

[uglysteve]

soaked it in liver of sulfur a couple times
Lubed it with Mihecs lube oil.
All beside the point.

[cbrick]

I dunno if liver of sulfur is good, bad or indifferent for the mold but it does make me really curious . . . Why?

Rick

[dragon813gt]

I'm assuming to prevent tinning.

[tomme boy]

It is to oxidize the brass so nothing sticks to it.

[Hamish]

I think that is a great idea, and because Lee uses this system with a wave washer on their 6 cavities, the parts can be ordered if you couldn"t find them locally.

And, anytime you do anything to alter the golden sensuousness of a brass mould, some of these guy's are going to howl like a stuck pig, good reason irregardless,,,,,:lol:

[uglysteve]

Hehe. Thanks. I don't care how it looks...only how it works. And now it works great!

One other fix: I noticed that the alignment pins have a tendency to move just a little. Enough to cause a loose mold with uneven bullets. I drilled and tapped the front and back of my mold and put grub screws in to hold the alignment pins in place. Works great.

[paul h]

I think that is a great idea, and because Lee uses this system with a wave washer on their 6 cavities, the parts can be ordered if you couldn"t find them locally.

And, anytime you do anything to alter the golden sensuousness of a brass mould, some of these guy's are going to howl like a stuck pig, good reason irregardless,,,,,:lol:

You have to admit, they are absolutely beautiful when they arrive.

http://sphotos-a.xx.fbcdn.net/hphotos-ash3/563530_10200484617379184_1056676625_n.jpg

That said, I really do prefer the look of a well used mold.

[Le Loup Solitaire]

A sprue plate or cutter should sit dead flat on the tops of the blocks. There should not be any up and down play or slop and really no need for tightening it down or using pressure washers/lock washers of any kind. But when the mold is tilted the cutter/plate should slide or rotate on its own weight. All bullets should have the same height. If there is a fill-out problem it can be usually traced to a pour stream that is too thick and overwhelms the sprue feed hole and does not let the air in the cavity escape. it takes some trial and error sometimes to regulate the pour stream and get it right. Over tightening (down) the cutter also can cause a problem with venting as well. If an end cavity is not filling out regularly then try filling it first every other pour and don't be hesitant to raise the pour/alloy temperature in conjunction with which end you start to pour from. A lot of molds seem to have their own personalities; what works for one mold may not work well for another. It pays to experiment and when the proper info is found/established, record the data/info on a 3x5 card so you don't have to do it over again the next time. Include temperature, the way you pour, mold lube if any, alloy...and any other tricks or tips that you pick up. Makes life easier the next time around. LLS

[Spawn-Inc]

I think that is a great idea, and because Lee uses this system with a wave washer on their 6 cavities, the parts can be ordered if you couldn"t find them locally.

And, anytime you do anything to alter the golden sensuousness of a brass mould, some of these guy's are going to howl like a stuck pig, good reason irregardless,,,,,:lol:

fixed it for ya, unless that was intended, regardless though it's fixed :)

i thought the block the OP was using was a steel one lol, but thankfully my mihec molds have been just fine upon arrival.

[freebullet]

Yer sprue plate is to tight. That's the only time I've ever got flashing out on the end like that. While the screw in that end may help, it can create a situation where the center cavities will have flashing. I run sprue plates loose enough that they can simply be flopped open by flipin the mold with no up & down movement in the plate.

I have no issue modifiyin a mold, all my lees have multiple mods. I never had a need to modify a mold that shows up perfect. If it were mine I'd remove the og plate screw & plate. Use sticky sand paper of 320-400 grit place it on a flat table & lightly surface the mold top. The lube it & tighten the sprue as described above & go cast.