358156 casting question

[pmer]

I have a question about my 2 cavity lyman mold. It seemed to consistantly not fill the cavity next to the sprue plate screw. The gas check portion would be rounded, but if it did fill out the base of the boolit would like it puddled. The other cavity was working good and I eventually finished my session just using the one cavity.

I could get the that cavity to work for a couple of fills by cleaning it with a alcohol wetted Q tip. I did have it soaked with WD-40 over the winter and cleaned it alcohol and tooth brush before I got started.

Boolits were dropping out of easy and I was using WW.

[fuddyduddy]

I have this design in both SWC and HP, both of which happen to be single cavity! HOWEVER,...(ahem),... with most 2 cavity moulds the reason one or the other pour is incomplete is either because (1) air got trapped in the cavity and could not get out of the way; or, (2) the mould is not hot enough; or, (3) the alloy temp is not high enough. I regularly lower the bottom of the mould into the molten alloy for a few seconds to get the initial temp up.

When you prep your mould, try any of the spray degreasers, using Q-tips to get the goo out of the corners. Then, prep with a paper match or carbon mould prep spray.

This is a great bullet design. Hope you have success with it!

[Bret4207]

The slight air gap between mould body and sprue plate can cause the sprue plate to be just cool enough to cause poor fill out. So can poor venting. My 358156 demands an air drop style of casting, that is I can't have the ladle or pot nozzle in contact with the mould, I have to hold it an inch or so away.

[btroj]

They various styles on casting. You might need to keep the spout away from the mould, pour in the center of the sprue hole, or pour into side of sprue hole so the lead swirls into the cavity. Some moulds just have a specific need. Find what that need is and all will be good.

Brad

[pmer]

Thanks guys, I did have the mould pretty close to the spout. I use the bigger Lee melter and the pot was getting low during the time I was using this mould. I turned it up when I noticed the temp was down to 600*. I'll check the vent groves with a tooth pick to see if there is gunk in them too.

Phil

[Tim357]

What btroj said. I cannot get good fillout unless the ladle is in firm contact with the sprue plate. All those pretty pictures of mold with the large lump of lead as a sprue don't apply to me. Full ladle, spout hard up against the plate, hold for a few, then disengage. Then I get a well-filled base

[pmer]

I think I had an aah haa moment with that cavity... Looking at it again last night I noticed some vent groves that don't go all the way to the cavity. 2 on each half of the block towards the nose end of the cavity.

My theory is that it fills slower and starts to solidify too soon? Does this make any sense?

[Larry Gibson]

pmer

Casting hotter should help as you and others have mentioned along with leaving a good sprue on the plate. This keeps "pour pressure" on the alloy to complete the fill all the way to the bullet base. Stop the flow too soon and you get irregular fill out of the base. Also you might have oil in the sprue plate screw hole. When the mould heats up after a couple castings the oil vapor can bleed over to the cavity causing a non round GC shanks also, worth checking out to see.

Larry Gibson

[LAH]

Be sure the cavity is clean, this goes without saying.

Loosen the sprue plate until it will swing freely. Don't over loosen, just enough to allow it freedom of movement. I cast with most all my moulds this way. Just my two.

[Roundnoser]

Larry Gibson basically said what I would suggest... I have a TC 50 cal. Maxiball mold that would not fill out completely at the base (just under the sprue plate). I corrected the problem by running my lead a little hotter, AND allowing the molten lead to "pool" and swirl on top of the sprue plate for an extra 1/2 second (you know what I mean). That does 2 things...keeps the lead from solidifying too soon, and keeps the lead flowing into the cavity with steady pressure.

Also...are you using a fan or something to cool the sprue before cutting it? Or, are you waiting very long between pours? -- If yes, your sprue plate and top end of your mold might be cooling off faster than the block. just my thoughts...

[pmer]

Thanks everyone, I've been reading here about fans and hot plates but have not tried them yet. I would wait around 3-4 seconds before cutting the sprue off. And would usaully have a nice puddle on top of the sprue plate.

I was trying to pour straight through the hole and can do it must of the time but I have one bad eye and sometimes end up pouring to the side of the hole.

I bought this mould used and it's the second time I had it out for use. It didn't seem to have this issue the first time so I will monitor melt temps better and see how that works.

Phil

[GP100man]

It`s like Larry Gibson said , as the mold heats up good the lube what ever it may be creeps & vents from the sprue plate screw hole .

I oil my steel molds with 3-in-1 oil & have to clean the hole everytime or get exactly what your describing.

Openin the vents will help & I like to put a small bevel on the mating surfaces under the plate also .

My problem is gettin the front band filled out sharp !!