Having Mold Fill Problem

[tacofrank]

I have a Saeco #382 4 cavity .357 mold. It cast beautiful bullets in cavities number 2,3,and 4. Cavity (Farest from handles) 1 doesn't quit fill the base out. I am new to a 4 cavity mold. Have several 2 cavity molds. I can raise the lead temp to frosting and #1 fills out great. What am I doing wrong? Add Tin? I am using range lead mixed with wheel weights.
Long time caster but feel like a newbie. Help!!!
Thanks,
TF

[AlHunt]

I have a Saeco #382 4 cavity .357 mold. It cast beautiful bullets in cavities number 2,3,and 4. Cavity (Farest from handles) 1 doesn't quit fill the base out. I am new to a 4 cavity mold. Have several 2 cavity molds. I can raise the lead temp to frosting and #1 fills out great. What am I doing wrong? Add Tin? I am using range lead mixed with wheel weights.
Long time caster but feel like a newbie. Help!!!
Thanks,
TF

You answered your own question. Heat.

Cast them frosty.

I start out around 800 until I'm dropping frosty bullets and let it slide back into the 700's.

A hot mold is a happy mold.

[cwlongshot]

Only a couple reasons for this.

1) Heat

2) Insufficient venting

3) Oils.

Be sure you have a good strong stream a d fill envisioning the lead splashing up from nose to base like a basketball swoosh!

Its not Tin if some cavities fill nicely. But yes TIN generally helps fillout.
CW

[ShooterAZ]

If you are casting with a bottom pour pot, you could try reversing your pour sequence. Pour a healthy sprue and let it overflow a little, and leave a large puddle on top of the sprue plate. If your alloy is really tin poor, it wouldn't hurt to add a little.

[kevin c]

I'll go with Shooter AZ's suggestion on pour sequence as a quick and easy first approach.

Always filling from the same end means, from fill to sprue cutting/dumping, that the first cavity filled stays in contact with hot alloy longer than the last, and the more cavities the greater the differential. If the mold isn't hot enough to start with (preheating) and/or cools quickly (aluminum mold, or cold/windy working conditions) the cavity always filled last may never get to ideal casting temp. Hotter alloy helps, but has the downside of maybe getting over frosted and undersized casts from the other cavities.

Since you found that hotter alloy works I suspect reversing the filling order will too. If you don't want to change alloy temp or add expensive tin you could go with the bigger sprue puddle, change your cadence, or fill alternating the start cavity far and near.

[tacofrank]

Thanks for your reply Kevin. I think you guys are a fountain of knowledge. I am going to apply the combination of suggestion you all have offered. You guys are the bomb!!!
Thanks,
TF

[tacofrank]

Thanks for you reply and your Youtube link (Great video). I think the combinations of suggestion you all gave will get me cooking on all 4 cavities. I'll clean the mold better the next time I cast, get my mold hotter, and rotate my pour sequence.
Thanks,
TF

[tacofrank]

Thank you all for your help. This site is awesome!
TF

[MT Gianni]

Write down what works for it on a piece of paper and store it with the mold. It never hurts to have a mold notebook as well.

[Conditor22]

IF the base of a boolit doesn't fill out completely, most likely the sprue plate is too cold. warm it up with a propane torch like this
https://www.amazon.com/Worthington-336737-WT2301-Trigger-Propane/dp/B004FPZACE/ref=sr_1_6?crid=2JMHP3F586161&dchild=1&keywords=propane+torch&qid=1628011381&sprefix=propane+t%2Caps%2C273&sr=8-6
the torch is also great for heating up the bottom pour spout if/when it gets cold.

Leave a quarter-sized puddle of lead on your sprue plate -- helps keep the sprue plate hot and helps insure complete fill.


I tested this theory by taking a cold mold and heated up only the sprue plate with a torch then cast a boolit. The base was perfect, the rest of the boolit left a bit to be desired.

[Buzzard II]

I agree with MT Gianni. Keep a note book and you may want to use a good thermometer also.

[bangerjim]

Heat.....heat........and more heat. Generally solves 90% of cavity fill problems.

Pre-heat ALL your molds on an electric hat plate to FULL casting temp, not just warm like on the edge of the casting pot! Solves all my problems!

A a bit more Sn helps to........if you have any.

[gwpercle]

+ heat ... cast right at a light frost ... frosty does no harm and helps a powder coat .
Try filling cavities from the far away one back to cavity closest to handle joint .
Sometimes that helps keep the far one hot ... cavity closest to handles hold more heat .

I had to make casting adjustments with my first 4 cavity aluminum mould ... that far away cavity wanted to run cool .. filling it first helped it keep the heat up .
Gary

[243winxb]

My Saeco 4 cavity .357 mold required opening the sprue plate holes a small amount. But then the taper leading to the hole needs corrected.

The sprue plate may be to tight. Loosen to to give more clearance. A thousandths or two.

[Dusty Bannister]

When having issues getting well filled cavities, it might be helpful to let us know if you are ladle pouring or bottom pouring to fill the mold. If ladle pouring, and using a large ladle, you might be running out of heat as you empty the ladle into the fourth cavity. This does not usually happen with bottom pour methods. But allowing the heat time to transfer to the mold from the melt might result in a cold final pour. Also, if you fail to move the mold under the nozzle as you fill the cavities, you will have more heat loss from the melt before it gets to the cavity.

[243winxb]

Pressure cast with a bottom pour. Spout in full contact with mould.

[AlHunt]

Pressure cast with a bottom pour. Spout in full contact with mould.

That is funny. I just switched away from pressure casting after about 30 or 40 years and feel I get better fill out. Plus the big sprues are easier to deal with than all the little buttons.

We all work different.

[243winxb]

Pressure cast is last thing to try on my list. As cast bullet weights are much closer with alloy dropping into the mold. Yes, big sprues are better.

More heat fixes many problems.,

[toallmy]

As a last resort you could try breaking the edge on the in side top of the blocks , to aid in venting .

[Cap'n Morgan]

If your head isn't already spinning out of control ;-), here goes:
In my humble opinion, most fill-out problems are caused by inadequate venting.

Using more heat will often cure the problem by keeping the lead molten a little longer, thereby giving the trapped air time to escape.
But the underlying problem is still poor venting!
Many people claim better results from ladle casting than pressure casting. Again, ladle casting allows the air to escape, while
pressure casting blocks the airflow from the sprue hole (and often fills the cavity too fast for the air to escape)
At the same time it presses down on the sprue plate, again blocking for the air to escape between mold and plate.

In your case the sprue plate could be a little too tight. If plate and mold blocks are not totally flat this can cause a slight gap between
them, getting progressively larger towards the end of the mold - which can explain the #1 cavity giving you trouble while
the rest are filling fine.

Try shimming the sprue plate so that you have a visible gab between mold & plate and give it another try. This will tell you if venting is
the culprit - or, if you're using a bottom pour pot, keep the nozzle slightly above the plate to allow the air to escape around the stream of molten
lead. For this to work, you may have to enlarge the holes slightly as someone suggested.

[Larry Gibson]

Most all "range lead" and COWWs is going to be antimony rich and very tin poor. You answered the question; add tin. Add 2% tin. As to heat; No need to "frost" the bullets. I you use a bottom poor and are filling #1 cavity first the problem is probably the alloy sitting in the spout has cooled. Either raise the temp a bit and/or let a small squirt of alloy out just prior to putting the mould under the spout and cast at the same temp. The alloy is best at 700 - 725 degrees. If you are filling the #1 cavity last then let a large sprue develop on the plate, even if it runs off, with that molten alloy boiling back up out of the cavity.

Also if you are casting set a tempo that keeps the mould temp consistent and the alloy in the spout still hot. If you dump the bullets and then inspect them before closing the sprue plate and casting again the mould will cool a lot as will the alloy in the spout. I suggest when casting that you cast. Inspect the bullets and cull out defects later. That will set up a proper tempo. Although, when warmer and the sprue takes longer to solidify dump the bullets, close the sprue plate, cast then inspect while that sprue is solidifying.

[rintinglen]

^^^I concur. A little tin and cast fast, to paraphrase the Gambler, "You never check your boolits when you're casting at the lead pot, they'll be time enough for checking, when the Castings done."
But I would also thoroughly clean the vent lines on the problematic cavity and, if need be, refreshing them lightly with a knife-edge swiss file. I had a similar problem with a 358-477 4 cavity that had been heavily used and had the vent lines mashed shut.