Nose Wrinkles!

[Potsy]

I wasn't real sure where to post this. So I thought I'd just put it here

I've been casting for about 10 years. I've got a few Lee Molds, a few Lymans, and 1 MiHec Aluminium 6 Cavity H&G 68. I have sort of figured out the technique with them and can cast without TOO many culls (I may be too picky). No wrinkles, filled out bases, smooth sprues, and filled out driving bands MOST of the time.

BUUUT, I've got a MiHec 270-SAA clone and the MiHec 225 CM both in 2-cavity brass and I have devil's own time with them.

A little background, I cast with a Lee pot (it's a drip o matic that I just ladle out of anymore because I had zero luck with bottom pour and couldn't really figure out any advantage) set on 8-9. I clean my molds and try to keep the oil out of the cavities (which should burn out after a couple dozen cycles anyway). I've poured fast, I've poured slow, I've tilted the mold, I've tried holding it straight up, I've tried keeping it cool, I've tried frosting the daylights out of them, but still, I wind up rejecting over half of the SAA's and do well to keep a fourth of the CM's and both only get that good after a LOT of cycles (like over 50). Lots of nose wrinkles on both and the front driving band not completely filling out on the SAA. Both cavities, both mold halves. Just every now and again I'll get the perfect bullet. So I know it CAN do it, I just can't make it happen more than occasionally.

I know it's all pretty subjective, but does anyone have any ideas? I like the CM and LOVE the SAA, but casting them is SLOW going.

[bangerjim]

Grease & oil are not your problems! They do NOT cause wrinkles.

Buy an electric hot plate and use it to heat all of your molds to full casting temperature (NOT just warm) B4 ever starting. Wrinkles are caused by cold molds and cold alloy. Brass loves to be VERY HOT and they take a long time to heat up. Much more than aluminum.

Try the hotplate and your nose wrinkles will be a thing of the past. Everybody should consider a hotplate as standard equipment, just like a lead pot and a mold.

banger

[Potsy]

I'll give the hotplate a whirl. Been thinking about one for a while and just never sprung for one.
I've been running it hotter than the hinges on the gates of hades, but I've wondered if there's not a heat "distribution" issue.

Thanks!

[Beagle333]

I love my MiHec 45-270SAA. I'm even in the new GB for second one! As Banger said...... Heat that baby up! Brass likes heat.

[tja6435]

Hot plate will fix your problem. I like the Oster hot plate Walmart carries, runs around $19 around here.
A PID controller for your Lee pot may help things as well.

[Potsy]

Tell me more about this PID controller. I've never heard of such.
I prolly oughta spring for a thermometer too, just never needed one.
I've always just run my steel and aluminum molds hot (I don't fret frost) and rocked on. Brass, apparently, will be a shade more "involved".

[Beagle333]

Not a bad thread to start with...

http://castboolits.gunloads.com/showthread.php?272029-Hotplate-for-mold-heating

[bangerjim]

There are many threads on here about how to implement digital controllers on lead pots. Do a search and you will find a bunch of info.

Many use them......I don't, even though I engineer, design, sell, and install large systems that use them on industrial heat treat systems! A PID (proportional/integral/derivative) controller allows one to input a set point and control the pot heating element around that set point, as long as it is wired up correctly and programmed right.

[country gent]

Pre heating the loulds to temp will help alot, What ladle are you using? Some open the spout up on the rcbs and lymans to around .205 - .210 to get a faster fill of the mould getting the lead in faster while still molten. Getting the mould up to temp it wants to run is the most important. a cool mould will cause wrinkles as the lead cools and solidifies before filled. A thermometer will help with knowing actual temp and reproducing what works. Alloy will have some effect on temp along with what the mould wants. Start with an alloy temp of around 700*-725* and preheat the mould to 350*-400* to start out the next session. If you get good consistant bullets cast there and try varying temp down 10* at a time to see where the lower end is. Asing a long session with upper range temps can result in a slower pace and frosting. Knowing where the moulds upper and lower temps are for a given alloy helps alot.

[Yodogsandman]

You could try pouring off some alloy from your ladle, warming the spout prior to pouring any into the mold. It may be that the first part of your pour into the mold is with alloy that's been slightly cooled from a cold spout. Or maybe you're not making a new dip for fresh, hot alloy for each casting cycle? Do you fully submerge the ladle each time to keep the ladle heated up, also?

[Tenbender]

Banger is right on on this one. I just bought my first Lyman mold the other day. I had a bad time with the nose . When I got it hot enough I had beautiful boolits. It take's lots of heat on a iron mold.

[Potsy]

Weeeell, I had a real "DUH" moment tonight.

First off, thanks for all the replies. I did pick up on a couple things to watch for and try, so they were not in vain.

I went to Wally World and picked up an Oster Hot Plate (as recommended). I went out to the shop and stuck my ladle in the drill press and picked out a bit that just 'cleaned up' the hole a bit and then some. I sat the 270SAA on the hotplate (I set it for just past medium and held my hand over it and my casting pot just for some idea how hot is was vs. the pot). My first few cycles were wrinkley, but much better than a cold mold. I dipped the end of the mold in the pot for a couple minutes, poured a few more cycles, and they were getting better, then, it struck me.

Some time back (about the time I got my brass molds), I placed a thin, aluminum tray, upside down, behind the towel that I dump my bullets out on on my bench. I place the mold on the tray while waiting for the sprues to cool. Then it hit me, I'm no engineer, but I'm pretty sure that the tray (that I've been using for the last, like, two years) was working as a heat-sink. DUH!!!

Of course, the only proof I have that that was happening is that after a few more cycles (after setting my mold on a piece of leather instead of the aluminum tray) is that nearly every bullet I cast after that was nearly perfect!!! I'm gonna try to run the 225 CM this weekend. That thing has been real tough and I suspect it'll be daylight and dark NOW THAT I'VE GOT RID OF THE TRAY!

Things were working okay with iron and aluminum molds, but it must have been sucking just a bit too much heat out of the brass. I suspect my bullets out of my iron and AL molds will be better on average as well.

So pardon a guy that was a bit slow to catch on to what was going on (even though he's been casting for 10 years) and thanks for all the help!!!

[snglstack]

Aha! The rest of this is just to add length cuz it said my original message was too short.

[bangerjim]

I never lay my molds down! A metal surface sure will suck out the heat. I occasionally will set a mold on the top of the pot but only for a couple seconds to get another grip.

Brass needs to be run HOT HOT HOT!


With my flat-top lab hotplate, I get perfect drops from any mold on the 1st pour. Ya gotta heat those babies up to full casting temp, not just warm! I water drop all my boolits just to cool them, not to harden them. If they do not sizzle sharply when hitting the water, your mold and alloy are too cold. A good test for temp I have used for a long time. No need for PID's and thermometers! Just good old common sense.

banger