Cast Boolit Surface Appearance

[Michael J. Spangler]

hello great gurus of casting.
i spent my afternoon working with the lovely 311365 i just got in the mail, and really enjoyed it.

I notice that i was getting some splotchy surfaces on the boolits from time to time.

i assume it's from nasties left in the lead, maybe some carbon left from fluxing? i was using a lee bottom pour furnace, and for the most part was pressure pouring.

i also noticed less of an occurrence when the mold was cooler, same goes for my 454200HP brass mold.
but it doesn't really look like they're getting too hot and getting frosty?

i run the pot around 675 or so and was using straight WW

i see so many pictures of perfect boolits out there, i want to be part of that crowd ; )

let me know what i'm doing wrong. p.s. this new mold is amazing, i can't say enough about it. it cast great from the start and the boolits just about jump out of the mold, half of the time when i tap the handle nut to open the mold they both drop on opening. awesome!

http://i286.photobucket.com/albums/ll105/MJSpangler/BE44E4C3-EEC8-4006-B61E-9D17AB07AB2F-13002-000002DCCAF296CF.jpg

http://i286.photobucket.com/albums/ll105/MJSpangler/64A1DD8E-C39C-4163-9DBB-F735D5AE4DD7-13002-000002DCC52FB3F1.jpg

clean smooth boolit on left, splotchy boolit on right. sorry for the camera phone pics

[btroj]

Mould temp. The ones that are more of a mat finish are from a hotter mould than the shiny ones. Those with some mat, some shiny are from uneven heating of the mould. Bet the mat spots are from the side that is closer to the other cavities.

Get into a good rhythm and they will all be similar in appearance. How much weight and diameter variation do you have?

[runfiverun]

heres the odd thing:
my wife makes awesome,square drive bands,well filled out, perfectly shiney boolits.
mine are all flat grey, i can see the mold lines and the cherry cutting marks in mine.

[geargnasher]

Dang, Lamar, how'd you swing that? I'm lucky that mine still wants to go shooting with me!

As far as those splotches go, I see a lot of little dirt inclusions on the surface, typical of a little dross and dirt being caught under the melt on the bottom of the pot. Wheel weight metal is full of impurities, metallic and otherwise that cause the not-prettiest boolits, but most of the time as long as they're consistent and filled out, looks matter not to the shooting. The dull spot at the nose base is a hot spot in the mould, it's getting hotter there for some reason than the rest of the cavity, hence the difference in finish appearance. Basically it looks like you're dancing the line between having the mould a fuzz too hot (dull spot) and a fuzz too cool (I see some wrinkles on a drive band or two, particularly in the middle and lower right in the "group" pic. Also, just left of center in the pic, there's one with a pinhole void in the middle lube groove, I'd cull that one and shoot the rest, they look pretty darn good to me.

BTW, most of mine look like Galvalume roofing metal. I get better fillout that way than when I run the moulds cool enough for shiny boolits.

http://castboolits.gunloads.com/attachment.php?attachmentid=28901&d=1296091775

Gear

[Michael J. Spangler]

alright so i need to work with regulating the heat more.

i think it's time to clean my pot really well. i flux a few times throughout a pot and still pull up some junk each time.
i think it's a lot of junk that stuck to the walls of the pot, time for a wire brush i guess.
that wrinkled boolit on the bottom of the batch picture is probably the worst one in the whole bunch. this sucker cast beautifully.

thanks for the help guys

by the way, awesome pic gear

[Sasquatch-1]

I tend to get wrinkles in my bullets right after I lube the spru plate and pivot point. I use candle wax when I do this and sometimes a bit works it's way into the mold. I just set the mold on top of the melted lead and let it get hot so it melts this stuff out. Be careful because it will take a while for the bullet to cool if you start casting right after this. (I use Lee molds)

Also, if you haven't already done it, you may want to get a tube of valve lapping compound from an auto parts store and lap the spout and plug. I have an old ten pounder and found that doing this reduce the drips considerably. Didn't end them just reduced them.

[Michael J. Spangler]

I must be lucky. Me lee doesn't drip.

[cbrick]

Michael, that is a great NOE mold isn't it?

Haven't had much chance yet to work up loads with mine but I will get to it. I'm curious how fast I can push the velocity with that nose design, if it will shoot well at 1900 fps I'll be a happy camper. Sure is a purdy boolit.

Most of the booltis in your picture look quite good. Let us know how they shoot for you. :mrgreen:

Rick

[MBTcustom]

I think you are right where you need to be.
Clean up your alloy a little, and slow your roll just a little and you will get rid of that frosting. When I am casting rifle boolits, I watch for what you have going on there, and slow down just enough to keep it right there, or a little shinier.
I think boolits that are half-frosty are perfectly acceptable. I try to stay away from the fully frosted look, and I don't want them so shiny that (like Lamar's wife), you can't see the cutter marks or the vent line dots. You are trying to maintain a delicate balance of alloy temperature vs. mold temperature, and the boolit tells you how close you are to that place.
Your boolits tell me that you are a little inconsistent with your cutting, mold temp, and speed of casting. Lasso those varmints, and corral them and you will get better results.
If you are not using a thermometer, get one. Run that alloy at about 650*-700*.
Flux it with sawdust/chips and stir it with a wooden stick.
Clean the mold with soap and water and a soft bristle toothbrush, and blast it out with carburetor cleaner followed by an air compressor or some "canned air". If you are one of the ones that "smokes" your mold, go ye forth and sin no more.
Start casting hard and fast until you get your boolits to look exactly like that halfway frosted one.
slow your roll just a tad until they start looking shiny and once you find that groove, ride it for all it's worth.
Another thing, watch your sprue puddle and as soon as it freezes, count "One one-thousand, Two" and cut it right then. If you have a shiny, proud, bump,(like I see in many of the ones in the picture) then cut sooner. If you have a frosty divot,(I see a few of those too) then wait another second and then cut it. Once you find where you need to cut for that alloy, and that mold, at that temperature, do it the same every time. You want flat based boolits.

[Michael J. Spangler]

Thanks guys

Yeah there are some inconsistencies on the pace of casting and cutting in this bunch. I was trying to feel it out a touch. It's way different that casting with the steel and brass molds I own. This is my first aluminum.
I'll work on pace and try to clean the alloy up a bit more, and to really scrub my pot out.

[Old Caster]

When pressure pouring, it is a good idea to slow down your pour velocity as much as possible. When alloy goes in at a high velocity, dirt doesn't have a chance to float to the top. You can't do this if not pressure pouring because you won't get fill out. This can be a pain though because it is more likely that you will get spout freeze or a little dirt in the spout will change the rate of flow and pot level matters also. I frequently check the flow by just pulling the lever a moment to see what it looks like. I want it to be a solid stream all the way to my ingot mold catcher which is set on the bottom plate of the pot or possibly a little slower. I also sometimes whack the spout on the side if the flow looks like it isn't coming out of the nozzle straight. If I am loading just blasting bullets, or using a poor quality mold I pour with a faster stream velocity and don't pressure pour and even that velocity can vary a lot depending on how good or bad the mold is. If you see a pin hole in the bottom of your bullet when you open the sprue plate when pressure pouring, you have your pour velocity too rapid and the dirt couldn't float up. If you need ultimate accuracy, pressure pouring is a better method but it takes decidedly more experience to do it properly without an over abundance of aggravation because it is harder and slower. Also the larger a bullet is, the easier it is to get away with less tin in the mix and the smaller, the more is needed to get proper fill out. -- Bill --

[Michael J. Spangler]

Thank you bill. I'll try to slow down the flow a bit to see how that works.

Overall I do have great fill out and very few imperfections beyond the couple of wrinkles and a little crud spot here and there. Definitely shoot able. I just want them to be sexy.

Thanks guys keep the info coming.

[Tonto]

Having similar experiences with the same mould plus base finning. I altered the pot temp, flow rate and everything came together perfectly. Too hot and fast, blotchy bullets and fins on the base and sometimes the nose. Blocks are clean so velocity and heat were the culprits. No matter how smart you think you are, sometimes you have to step back, question your assumptions and learn things all over again. Everyone have a great Christmas.

[Michael J. Spangler]

so why does the slower flow give a better finish? is it the swirling of the lead leading to more oxidation of the stream?

[runfiverun]

it allows better venting of the air.
i generally have better luck with long boolits if i aim in the sprue hole and fill the mold rather quickly.
i have to learn how long it takes to fill the cavity's and pour the sprue then stop, otherwise i end up with quite the mess or with onlu partially poured boolits.
this takes some skill and good lighting on my main pot, as it has two pour spouts, so i am filling both cavitys at the same time.

[Old Caster]

I think the only reason is because the dirt has a chance to flow up and out. I experimented for a while tipping the mold a bit so I could slowly pour down the edge of the tapered part of the sprue plate opening and quite often I would see a piece of dirt suddenly come out of the spout and immediately back up and stick on the nozzle. I think I made dirt free bullets but without pouring velocity the base of my bullets weren't perfect which is why I eventually went to pressure pouring everything if the mold is up to handling it. After you get some practice, pressure pouring is very close to as fast because you have to wait for the sprue to congeal anyway. When I molded bullets for the AMU back in 1965, they had us just pour the lead straight into the mold plus we used lead that lacked tin and was very soft. We all shot good scores but since that time, I have used a Ransom rest to prove that accuracy is better if a proper alloy and pressure pouring is used. How much better is very minimal but if you want to win, everything is necessary. Some shapes of bullets in certain calibers can't be made to shoot well no matter what you do so if you have inaccuracy problems don't be too quick to blame your molding or reloading technique. -- Bill --

[geargnasher]

Having similar experiences with the same mould plus base finning. I altered the pot temp, flow rate and everything came together perfectly. Too hot and fast, blotchy bullets and fins on the base and sometimes the nose. Blocks are clean so velocity and heat were the culprits. No matter how smart you think you are, sometimes you have to step back, question your assumptions and learn things all over again. Everyone have a great Christmas.

Case in point, after 20 years of pouring my own somebody here grabbed my by the ear, sat me down, and told me how to REALLY make good boolits. Use a 12-quart dutch oven and a good propane burner, and a 1-lb Rowel ladle. Cast five cycles a minute and use a fan to cool the sprue plate. The trick here is HIGH VOLUME AND LOW PRESSURE. You just can't get that from a bottom-pour pot. Drill out the hole in the Rowel ladle to 3/32", and pour the stream straight into the center of the hole, dump it in there FAST until it gushes back out, then move to the next hole. You want to practically THROW the alloy into the cavity suddenly, not giving it a chance to solidify anywhere inside until the whole thing is chock full of alloy. You need a big pot to do this because it makes a royal mess with lead splashing and streaming off of the sprue plate in all directions, but it makes void-free, perfectly filled boolits that fly as true as you can launch them.

Just thought I'd pass that on since I'm a perfect example of someone who just threw out everything he knew about casting and learned over fresh again. Don't get me wrong, I still love and use my bottom-pour pot, but for the very best rifle boolits only a ladle will do.

Gear

[Sasquatch-1]

Thanks guys

Yeah there are some inconsistencies on the pace of casting and cutting in this bunch. I was trying to feel it out a touch. It's way different that casting with the steel and brass molds I own. This is my first aluminum.
I'll work on pace and try to clean the alloy up a bit more, and to really scrub my pot out.

To clean the pot try an old bore brush mounted in a drill. If you have a section of cleaning rod that will help get to the bottom.

[Old Caster]

The reason a ladle works so well is because it is constantly cleaned by moving it about in the pot and a bottom pour nozzle stays in the same place accumulating dirt and eventually passing it through. I also contend that if you want perfection, especially in a larger bullet, ladle pour. If you want the best you can get with a bottom pour, use the pressure method. -- Bill --

[geargnasher]

If you maintain your bottom-pour pot properly you'll never get any kind of junk in the bottom and only clean alloy will come out the spout, so no special monkey-business, chanting, or standing on one's head while pouring to compensate for garbage going into the mould. The ladle is superior due to being able to quickly fill the cavity with minimal turbulence while allowing the air to vent back out the sprue hole if you pour it properly, then the "gush" at the end tends to flush out any air bubbles that tend to form under the sprue plate. When I've tried pressure-pouring with a bottom pour it usually clogs the vent lines of the mould and causes flashing and bits of "hairs" from the vent lines to slip out and get stuck on the mould faces where it accumulates and starts to "Beagle" the mould. If you need two PSI of head pressure to get fillout, maybe your technique needs a revisit, but if you're happy with it then I guess that's what matters.

Gear

[Old Caster]

I don't have problems with clogging vent lines with quality molds, but with lesser molds it most definitely is a proplem which is why I don't pressure pour with them. -- Bill --

[44man]

Bottom pour! Pressure casting! How do you pressure liquid? Pour a LARGE sprue that hardens before the boolit in the mold! Pour lead over the mold, all over the place. Such funny stuff where you need a computer to make a boolit.
Pour from a foot high, swirl the lead, pour on the edge, shake the mold. The temp has to be 1* perfect. Can you guys really cast?
It is the easiest thing to do EVER compared to all else we do.
A billion posts when 5 minutes with me will have you make perfect boolits all day.

[The Dove]

I like my boolits a little on the frosty side as compared to the shiny side... But, that is my opinion and we all have one.....

The Dove

[Hal]

Used to cast real hot and frosty didn't matter as bullets were perfect. Have settled down in later years, now having very good quality 5 and 6 cavity molds and I am moving a little slower.

[Michael J. Spangler]

I think I'm too used to my other molds and cranking out lots of handgun boolits. I need to slow it down. I can probably cast enough out of a pot to keep my rifles fed for a year.
Way different that pistol ammo.

Thanks guys

[Old Caster]

Mike, you have to somehow thread yourself through all the advice and decide which works the best for you. Watch the base fillout of the mold and you will have a pretty good idea what the rest of the bullet will look like. As you will find, when reading on the www, there are people that are so adept with such simplicity that they must amaze themselves . You just have to decide what is what and who is who. Good luck. -- Bill --

[Michael J. Spangler]

thanks guys.

there are all type on the internet, and i've had my fair share of forum work to have learned that. lots of info online, not all is good.

[Sasquatch-1]

One of the main reason I do not ladle pour is that my hand would shake too much and tinsle would go everywhere. If I had a steady hand and some six cavity molds I might try ladle. Strickly bottom pour for 35 years with Lee pot and molds.

If I start getting debris in the spout I run a piece of wire up it. If the spout starts dripping I twist the plug a few times. I do not look for absolute perfection in my bullets. I only cast handgun and get fair accuracy.

Happy New Years. :drinks:

[1Shirt]

I cast hot, and prefer at least some if not all frosting. Don't know for sure, but think that frosty holds lube better.
1Shirt!