Wrinkly bullets, need advice. How do you prep moulds?

[John Ciccone]

 I have restarted casting after a 3 or so years. I was using a couple of molds that I have used in the past, one from Lyman and another from Buffalo arms. In the past, I used Rapine Mould and was casting beautiful bullets with it. All of the moulds are iron (not aluminum) Today, I was casting, and applied a heavy coat of Mould prep to the moulds. The temperature of the lead wa 700 degrees, and fluxed. EVERY bullet I cast, from both moulds was very wrinkled and unacceptable. Even the grease grooves were broken with small voids. My assumption is that I have too much Mould prep and it is blocking the escape of air and inhibiting proper formation.

 Does that sound reasonable?

What d you use to prep your moulds?

[Daryl]

Your lead is too cold or the bullets or balls would have come out perfectly, after very few.

Taylor has and has used Rapine Mould prep- it works and he used one coat, only.

I like to spray my blocks whether, brass, aluminum or cast iron - they get a treatment of a single coat of MOLY bullet coanting spray. I've used Lyman and Ms Moly - both work well.
Seems to me, the Hoppes' is not good as it wipes off easily.
The sprays I use seem to coat the moulds identically to Taylor's moulds.
1 even coat, that's it. Set aside to dry.
I found casting pure lead, I use higher temperature setting. I have NEVER used a mould, but rarely does a bullet or ball go back into the pot.
The measure and weigh just about perfectly, every cast.
Here's a picture of round balls, cast in my .570" mould. Every one was perfect.
If they continue to be wrinkled, you lead is too cold, or perhaps you have contaminated it.
850F to 875F sounds better to me.
If the temp is causing the lead to blue skin, add 1/2" of 50/50 solder to a 20 pound mix. It will not harden the ball noticeably, but will help prevent the rapid accumulation of crust blue crust and wrinkled balls.

[John Ciccone]

Thanks. Come to think of, I am using a new pot, an RCBS bottom pour. And I followed the advice of the lead temp of 700 degrees, which is lower than what I did in the past.

[Dphariss]

Thanks. Come to think of, I am using a new pot, an RCBS bottom pour. And I followed the advice of the lead temp of 700 degrees, which is lower than what I did in the past.

I hate to say this, but I have never had a bottom pour that was actually worth a hoot and I had 2 different ones years ago.
With pure lead you need to run the pot pretty hot since it has a higher melt temp and will not flow as well as an alloy containing Tin. I use Mold Prep or smoke the cavity with a kitchen match or a candle. Smoking a cold mold is not recommended.
This insulates the cavity somewhat and slows the cooling slightly. I set the mold on the pot to preheat as the lead melts.

Dan

[Dphariss]

Thanks. Come to think of, I am using a new pot, an RCBS bottom pour. And I followed the advice of the lead temp of 700 degrees, which is lower than what I did in the past.

If the mold has vent lines like Lyman make sure they are open. A graver or a 3 square needle file  with the teeth ground off one flat will clean them. Burrs in the cavity may need to be removed if the grooves are cleaned. DO NOT enlarge the grooves just be sure they did not get burred over when the cavity was cut.
I never use more than a light spray of mold prep. It can plug vent lines. If the coating is heavy you probably should wash the mold prep off with alcohol or some such.

Dan

[smokinbuck]

Interesting, maybe I'm just living right. I've been casting RB since the 60's and have never used a mold prep of any kind on either my steel or aluminum molds, I also use a bottom pour pot. I heat the mold on the pot while the lead is melting and then just get started, rarely have more than a couple of wrinkled balls to discard. I have always made it a practice to clean and maintain my casting equipment and it lasts a long time. Typically the balls are pretty uniform in size and have a few weight variations, nothing major but I do weigh them all. I generally heat my lead to about 850 degrees during melting and then cut it back to around 750 degrees during casting.
Mark

[Daryl]

This is a  casting session - every ball - none went back into the pot.  I did not mention pre-heating the mould on the pot's edge - I thought everyone must do that, automatically.

If there is heavy shipping grease inside the mould, that should have been cleaned out before starting.  Any household detergent (grease cutting cleaner) should work, scrubbed with a

 toothbrush under the hot water tap until the steal/aluminum/cast iron actually gets wet.

there are non wrinkled balls in either of these piles. I rarely get any, unless I did not get all the oil out of the mould blocks.

I like to refer to cast round balls as jewels. If yours do  not look like these, we have  a problem, Houston.





a red red rose tone

[rich pierce]

Not seeing the pictures, Daryl. Anyone else?

[Daryl]

Interesting! I see them. I used the Add image to post function.

[45-110]

i start every casting session by spraying brake de greaser on the blocks and sprew plate. never once in 50 yrs have i used a "mold prep". there may be some thing to that, but never convinced myself it was needed. also you need a large puddle on the sprew plate as the metal cools it draws from that reserve. the additional puddle weight serves to fill out the cavity. i always use a ladle to cast too. that said, as a mold collector/hoarder i steer clear of aluminum blocks as they seem to gall easily under the plate. do have some brass/bronze ones that work nicely though
best
kw

[snapper]

He is talking about casting bullets. Not round balls.   Round balls are much easier to cast than a bullet.  Especially a grease grove bullet

I agree with Daryl. Try a higher temp

Fleener

[kudu]

your lead temp is too low and your mold is too COLD I prefer to cast in the HI 800'S or about 900 range.  I just did some casting last night outside on the deck only 75 balls, and the Temp outside was 27degF. but the lead was right at 900 and the mould stayed hot enough that I had to wait for a 3 second count on every pour before I hit the Sprue Plate.  Nice smooth Balls I tell Ya.

[Joc7651]

Cast hotter and heat the mold up more.

[xx54]

I had the same problem. It seemed like I couldn't get my electric pot hot enough. So I had some thin steel plate and made a lid for my pot that just lays on top. I couldn't believe how much hotter it got. This solved all my problems. It might be that your pot electric pot is like mine and they are not getting as hot as everyone else's.

[stikshooter]

All my molds ,steel /aluminum/NOE/BACO/Accurate get scrubbed with Dawn rinsed and dried then go to hotplate while my lead gets cooked . Unless I missed some grease/oil/lube the culprit for wrinkles is (for me) to cold a lead or mold will cause it ,throw the 1st 15 back it will get better . If not see the part I missed/Ed

[Standing Bear]

Using 20 lb Lee bottom pour. 10 lb started Rusting thru after 30+ years.  1,000* Dial thermometer w 6” probe. Turn on and place mold over the top.  As above, 800-850* works well.

I use Frankfort Arsenal mold release. WEAR EYE PROTECTION. Wear welding gloves and twist the sprue plate vs whacking it.  I pour 10, then 10 more place the mold on top of the pot and inspect/weigh the first 10 and repeat.
TC

[Daryl]

I always run my heat high enough to get even frosting of bullets. Thus, they are exactly the same weight within a grain

and are filled out nicely, no wrinkles.  These are cast in WW alloy. I-too wear gloves and twist the sprue plate to cut the sprue.

The only time I tap the pivot is when a bullet or ball sticks a bit. This happens less often if the mould is smoked, or mould prep used.