Troubleshooting Casting Defects

[justindad]

Is there a thread with examples of different casting defects, and how to resolve them? Maybe some guidance on what imperfections are acceptable for plinking?

My first session today gave me 95% reject rate due to rough surfaces, with a few wrinkles too. I might be too picky on the rough surfaces.

[44Blam]

Wrinkles are normally too cold or an oily contaminate...

[WheelgunConvert]

The 3 best lessons I had to learn:
1. Mould cleanliness is critical
2. A clean mould is worthless if it is not hot enough.
3. It’s a hobby, keep more and shoot’em anyway. Don’t lose the enjoyment in your long term pursuit of improvement.

[GregLaROCHE]

Clean the mold thoroughly to make sure there is no trace of oils that can cause wrinkles. Is there any tin in the alloy? It helps to get a better fill out. Flux well. Make sure the alloy and mold are hot enough.

If you post some pictures maybe we can give you more detailed advice about your problems.

[Wayne Smith]

And go to your profile and add a location. One of us may be close.

[justindad]

Alloy is 92-6-2 Pb-Sb-Sn from Missouri Bullet Company. Mold is new 358-124-TC-R4 5 Cavity PB from NOE. I did the 350F warm-cool cycle three times and then deposited carbon inside the cavities with a Bic lighter, following instructions that came with the mold.

In my shame, I melted my mistakes. Too bad I can’t do that in real life :)

Next time I’ll use the thermometer, and see if I can get smoother parts at some temperature around 350F.

FWIW - the roughness was like pitting, not like frosting. I don’t see colors in the pitting to indicate debris inclusions, but they could be really small.

[onelight]

What defects are acceptable for plinkers for you is your choice . I see a lot of cast that I would have put back in the pot. One of the reasons I started casting was the commercial cast bullets in the gun stores at the time had rounded driving bands , and other defects most leaded at even low velocity .
So for me almost any visible defect goes back in the pot even for plnkers .
Your choice choice I do make compromises on my short range 7 to 25 yard plinking ammo that I would not make on long range or hunting or cary ammunition .
One thing that seems to have an impact on how easy it to get good bullets is the bullet shape the fewer 90* corners on the bullet the easier it is a round nose bevel base is easier to cast , but l prefer Kieth style for my best.

[Dusty Bannister]

It sounds like your alloy should not be the issue. As long as you did not have junk alloy in the pot to begin with. What is the melt temperature? I cast conventional lube groove bullets at about 720F and do not cast HP bullets. But I do understand they need to be cast at a higher temperature since there is a lot more metal acting as a heat sink, so the melt cools too rapidly. I do not know if the carbon coating is an issue, but if you wipe it off with a clean Q tip and things do not improve you can always lightly apply it again. The purpose of the carbon it is speed up the break in of the mold.

Common problems. Incomplete fill or creases on the sides of the bullet. Mold and alloy not hot enough. Incomplete filling around the HP pins, Need more heat and a fast pour. Pitting with debris is dirty alloy or pot residue. Pitting without residue, still giving off oil vapor and not enough heat/time in the break in cycles. Round base casting, venting issue or pouring too slowly or missing the sprue hole. Will wait to hear what other issues you might have.

When you can provide photos, please show the nose, sides and bases so we can get an overall view of the problems you have encountered.

[GregLaROCHE]

350* seems a bit low.

[high standard 40]

You might try removing the smoke residue from the mold cavities. I have about 20 molds, aluminum and iron, 22 through 45 caliber, and not one of them needs smoked cavities to produce excellent bullets.

[Hossfly]

Get a hot plate and get your mold up to temp before casting. I get up to at least 400+ then over fill mold and let soak for a few seconds, before doing a run. This gets everything good and hot, pretty quick, then keep up your rhythm. Any oils should be out by then. I start casting at 725-750 and try to maintain that temp, easy with good PID control. Good thermometer makes a difference.

[popper]

Way to low temp, even 350 C is only 650 F and barely liquid. That alloy needs to be 730 F or so. Something big wrong with temp measurement?

[Gator 45/70]

Zn or Zinc is not you're friend

[mdi]

Not sure of my memory this morning, but other members can correct me if I'm wrong. IIRC the Lyman Cast Bullet Handbook has a trouble shooting section with pictures of defects and reasons for flaws. More than likely the 3rd Edition as I used it much more than the 4th.

My standards are pretty tight because I have plenty of time. I only have one 6 cavity mold as most are 2 cavity and perhaps your 5 cavity mold is adding to the culls because mold temp can vary from one end of the mold to the other. Rough finish can be from the carbon from smoking and frosting normally from high heat. I haven't found minor wrinkles to be bad for accuracy so I let some slip by. For me the most important "standard" is sharp corners on a flat base. Next is sharp corners on driving bands, grooves. And I don't like those tiny black "spots" from dirty alloy so I clean and flux often....

Like I said these are my requirements and some others will probably differ.

[Burnt Fingers]

Way to low temp, even 350 C is only 650 F and barely liquid. That alloy needs to be 730 F or so. Something big wrong with temp measurement?

350F isn't the same as 350 C. Not even close.

OP:

Did you clean the mold before the heat cycles?

How heavily did you smoke the cavities? They should have just a slight bit of color to them. Not totally black.

[Bazoo]

The art of bullet casting book has a section on defects and causes.

I clean my moulds with lighter fluid. With the mould hot and the blocks closed but sprue cutter open, I fill the cavities with lighter fluid. It boils, removing any oil contamination and leaves a thin carbon layer (I suspect). It doesn't cool a warm mould like brake cleaner would.

Defects acceptable to me include a small pulled sprue cut, a slight wrinkle or crease on a driving band, a very small inclusion in the lube groove, surface spider webbing or graying from needing fluxed (this I describe as visual imperfection and will largely disappear if you rub with a towel).

What I discard for is any roundedness of the driving bands. Any large inclusions, or any inclusions on the driving band. Wrinkles. Very large hole at sprue cut. And I reject any with a hole.

I'm more picky about rifle bullets than pistol bullets. I continue to be a better caster than I was previously so I'm always upping my level of desired perfection.

[oley55]

Is there a thread with examples of different casting defects, and how to resolve them? Maybe some guidance on what imperfections are acceptable for plinking?

My first session today gave me 95% reject rate due to rough surfaces, with a few wrinkles too. I might be too picky on the rough surfaces.

I guess there isn't a thread which identifies typical defects and causes other than tin content, temps and mold contaminants. Mores the pity as I was hoping there was one. I'd like to know more about sprue cutter issues; tear-outs, smears and etc...

[robg]

wrinkles =low temp or oil etc in mold .clean mold higher temperature or add more tin.

[GregLaROCHE]

Seems the first issue to address is the temperature. There seems to be a bit of confusion. Does the OP know what temperature he was casting at? A simple way if you don’t have a thermometer or you aren’t sure if it is correct, is to keep heating the alloy until the boolits begin to have a frosty look and then turn down the heat some. Frosted boolits are fine to shoot too.

[justindad]

Did you clean the mold before the heat cycles?

How heavily did you smoke the cavities? They should have just a slight bit of color to them. Not totally black.

I cleaned the molds with dish soap and a toothbrush before smoking. The flats between the cavities had a black coating, but the actual cavities did not have any visible deposits.

[Conditor22]

"I did the 350F warm-cool cycle three times and then deposited carbon inside the cavities with a Bic lighter, following instructions that came with the mold."

Heat cycling helps build a patina which improves castability.

I don't see where/when you cleaned the mold and how you cleaned it.

IF you heat cycled the mold before you cleaned it I would suggest cleaning the mold with either acetone, carb cleaner, brake cleaner scrubbing the cavities well with a toothbrush (any nylon bristle brush, [I use a denture cleaning brush from the dollertree])

Warming a mold on a hotplate set to 400° helps the mold cast well from the start

"Alloy is 92-6-2 Pb-Sb-Sn from Missouri Bullet Company" this is a good, easy to cast with alloy, though a little hard for most applications

In my shame, I melted my mistakes. Too bad I can’t do that in real life == we've all had poor results when we started casting (and often with a new mold) this is part of the learning curve.

Next time I’ll use the thermometer, and see if I can get smoother parts at some temperature around 350F. ==this doesn't make any sense to me

FWIW - the roughness was like pitting, not like frosting. I don’t see colors in the pitting to indicate debris inclusions, but they could be really small. == pictures are worth 1,000 words and make it much easier for us to help, many people don't describe things the same way and pictures don't lie :)

Diagnosis:
clean the cavities well (don't smoke the cavities at this point)
preheat the mold on a hotplate set at 400° (I turn my hot plate on at the same time as the casting pot)
Set/heat the casting pot up to 720°
Cast a few mold fulls with a quarter-sized puddle on the sprue plate, (wait for the sprue to frost over before cutting)
Now IF you're not getting smooth boolits lightly smoke the cavities.

One way to test the cavities to see if it's a heat problem is to pressure pour -- hold the mold up to the spout and fill the cavity stopping the flow of lead after you lower the mold and get a puddle on the sprue plate.

this is the important part---- post pictures of your results :)

[justindad]

Seems the first issue to address is the temperature. There seems to be a bit of confusion. Does the OP know what temperature he was casting at? A simple way if you don’t have a thermometer or you aren’t sure if it is correct, is to keep heating the alloy until the boolits begin to have a frosty look and then turn down the heat some. Frosted boolits are fine to shoot too.

I heated my molds to 350F in a toaster oven, and then went to casting. I’m pretty sure Inwas moving slowly enough that the mold cooled off.

When the top of the molten lead was perfectly clean, my IR thermometer gave me somewhere around 650F, but that method was found to be wildly inaccurate. After deciding the IR data was junk, I adjusted the heat knob up and down looking to see a change, but then my mold cooled down.

I’ll see how high I need to set the pot to get frosted bullets, and keep the mold in the oven when not pouring. Then I’ll cool the pot until frosting disappears.

[justindad]

Way to low temp, even 350 C is only 650 F and barely liquid. That alloy needs to be 730 F or so. Something big wrong with temp measurement?

350F is what I used to prewarm the mold. My measurement of molten lead turned out to be garbage.

[Stewbaby]

Get a PID from Hatch so you don’t have to keep fighting those temp issues

[justindad]

Pitting without residue, still giving off oil vapor and not enough heat/time in the break in cycles.

When you can provide photos, please show the nose, sides and bases so we can get an overall view of the problems you have encountered.

That’s the main issue. Perhaps I need to clean the new molds better, and repeat the warm-up & cool-down break in process, leaving the mold at 350F [or higher] longer than the first time.

I’ll save a few of my next failures for pictures :)

[white eagle]

Is there a thread with examples of different casting defects, and how to resolve them? Maybe some guidance on what imperfections are acceptable for plinking?

My first session today gave me 95% reject rate due to rough surfaces, with a few wrinkles too. I might be too picky on the rough surfaces.

your problems will cease the longer you cast
if you are fresh on the mold it may be the mold will get better as the casting sessions get more and more
seasoning it as you go along
wrinkles are a sign something is not up to temp either the alloy or the mold or both
hang in there

[justindad]

Thanks for all your help! Not only am I fresh on this mold, but molds are fresh on me!

[JonB_in_Glencoe]

Is there a thread with examples of different casting defects, and how to resolve them? Maybe some guidance on what imperfections are acceptable for plinking?

My first session today gave me 95% reject rate due to rough surfaces, with a few wrinkles too. I might be too picky on the rough surfaces.
justindad,
Welcome to the forum.

A casting defects thread is a great idea. I don't think there is one, at least not one with numerous photos and solutions.

You've received some good info so far.

Let me address one thing, that I don't think anyone else has covered. Wrinkles...
When I first started started casting, the first time I cast 22 cal boolits (NOE 225-55-FN), I got wrinkles. It's difficult to keep a mold with small (22 cal) cavities, hot enough...Heat is the secret to eliminate wrinkles. I finally figured out (with a suggestion by someone here), to use a Hot plate to preheat the mold, and when necessary, to re-heat the mold, if I am not able to cast fast enough for it to remain hot enough.

ANYWAY, the point I am trying to get to is, I did a test, a shooting test. I loaded a bunch of these wrinkly 22 boolits in 222 rem (let me mention, that I did inspect these for other flaws, and also, I did cull some that had real bad wrinkles). I also loaded a bunch of the same boolits that didn't have wrinkles, they looked perfect. I made sure to use the same alloy, same sizing, same lube, same loading tooling and procedures, into the same headstamped cases, and then went to the range and shot them. I was shooting off a bench at 100 yd targets, with a scoped Savage 340. Now, I'm not sure of it was the day? or what? but the wrinkly boolits shot better groups than the perfect boolits ...and those groups were the best that I've shot with that rifle :shock: :holysheep


Do you suppose those wrinkles have a similar effect as the dimples on a golf ball [smilie=p:

[GregLaROCHE]

I heated my molds to 350F in a toaster oven, and then went to casting. I’m pretty sure Inwas moving slowly enough that the mold cooled off.

When the top of the molten lead was perfectly clean, my IR thermometer gave me somewhere around 650F, but that method was found to be wildly inaccurate. After deciding the IR data was junk, I adjusted the heat knob up and down looking to see a change, but then my mold cooled down.

I’ll see how high I need to set the pot to get frosted bullets, and keep the mold in the oven when not pouring. Then I’ll cool the pot until frosting disappears.

IR thermometers don’t work well for casting boolits. You need a good thermometer that goes into the lead or a PID. Otherwise, do as I said before. Heat the alloy until the boolits begin to frost and then turn down the heat. This may sound like a crude approach, but it works. You can fine tune temperatures later.

[WRideout]

After a quick review of the NOE web site, it looks like your mold is probably aluminum. IME (using Lee aluminum molds) they like to run HOT. With my Lee dipper pot, I use an alloy of range scrap and tin, and turn the heat control on the pot to 3/4 of scale. Any more I preheat the mold by balancing it on the edge of the pot, or if I'm in a hurry, dip a corner of the mold into the lead. I usually get one or two pours that are rejects, but soon begin getting good, sharp boolits. I cast until they start getting frosted, then turn the heat down a little. I have never measured the temperature of my pot. If in doubt, turn the heat up until the results tell you it's right.

Wayne

[justindad]

I think so need to back up about a month here... I bought ~65 lb of lead, and it came in 8 lb sections. At the same time, I bought a Lee 10 lb bottom pour pot (only one available). The pot was barely able to hold the 8 lb segments, but it did and I melted it all down into 1 lb manageable ingots... except I left the pot full for when my molds arrived, hoping that would be a reasonable rust preventative (probably a very bad idea).

So last night I fluxed with some saw dust and stearic acid flakes. Not much dross came up, which seemed reasonable given it was purchased lead. Tonight I started the pot at 80% power, and noticed the lead at the bottom of the pot melted sooner than the lead exposed to air - perhaps the heat did not evenly distribute due to the higher setting and shorter time. Now the bottom 4 lb leaked into my ingot mold, while the solid top portion held the valve open. I figured it’d be good to see if any dirt was in there, so I did not refill it. I fluxed with stearic acid only, and nothing new happened.

Then I started casting with my mold at 350F, and saw sharper corners with the same pitting (very few bullets showed any foreign bodies in the pitting). Then I turned the mold temperature up to 400F (actually measuring the mold with a thermometer from NOE today), and the only change is all corners are crisp. Then I fluxed with saw dust and stearic acid. Fluxing now between each casting. Still no changes, so I turned the pot up to 90% power, and saw the molten lead turn red with no other changes (no frosting).

While leaving the mold in the toaster oven, I inspected the bullets. Having fluxed & cleaned before inspecting my work, I was surprised to find A LOT of dross had risen to the top before my mold got to 400F. This happened two or theee times, getting worse each time. Then the pour valve started getting sticky. So I figured the pot was dirty and emptied it into the ingot molds. The last full ingot cracked into two pieces when I knocked it out of the mold, and it has a burn mark in the middle. So I laughed at my glaring ignorance, and stopped until I can clean the large chunks of dirt out of the pot.

Dirt the last ingot crack because it is loaded with antimony, from the stream of 65 lb? Did it crack from dirt? Or both?

The pitting I have been seeing is in the pictures here. I may need to get my Fuji out and get real pictures tomorrow, since my phone isn’t doing a great job - just let me know.

I imagine I need to buy a hardness tester and sort my ingots... if I can find one.

279839279840279841

[bruce381]

mold to cold try 450 on you oven.

[Land Owner]

Pre-heat. Pre-heat. And pre-heat some more. After pre-heating the mold, "float" the mold on top of, and in the melt. Leave it there a while...+/- 2 minutes! ymmv. Turn the mold over and "float" the spruce plate in the melt for +/- 2 minutes too. Do both sides a couple of times. You can tell when the melt no longer sticks to the mold that the mold is ready.

Take the mold from the pot, tap off any melt sticking there, and pour a few dozen. Set the mold so it "floats" on the melt (or now smoldering saw dust). Inspect boolit(s). Wrinkle and frost free should follow at about 725F.

Use saw dust and a small amount of candle wax as flux. Cover the top of the pot liberally with saw dust and a flake or two of wax. Acid is expensive, imo. Even "floating" the mold on top of the smoldering sawdust will allow it to absorb heat.

My last session with a 2-cav., 22 Bator mold heated this way (not HP), produced 1183 keepers and 17 rejects. I was ecstatic! The planets aligned. HP molds need heat, especially on the internal hp pins. The way I give them heat is dipping the mold.

Rejects are a part of the learning curve. What works for you...not all defects are "bad". Plinkers are fun (they add expense as you "throw away" expendable components - though not for nothing) but nice boolit are confidence builders. This hobby gets better with time. Heat is your friend with molds.

[justindad]

Take the mold from the pot, tap off any melt sticking there, and pour a few dozen. Set the mold so it "floats" on the melt (or now smoldering saw dust).

Do you leave the ashes from sawdust on top of your pot while casting?

[justindad]

The 450F pre-warm temperature for the mold really helps. I got some frosty bullets, and I still have some surface roughness. I’m thinking that the surface roughness will improve as the mold ages. If it causes any problems, I’ll compensate with a polymer coat until My casting skills improve.
I cleaned the pot today, but I do not believe that was the main issue. I think my cracked ingot was caused by excessive heat in the pot. I’m going to anneal my frosty bullets at 375F.
Here’s a pic of samples from today.
279868

[gwpercle]

Don't smoke your moulds ... the smoke causes the roughness on cast boolits and just mucks up the blocks .
If you must use some kind of mould release then use a spray on dry lubricant that contains Micro Teflon particles (PTFE) in it . The Teflon film doesn't contaminate and being teflon ... nothing sticks !
The first time I tried this the boolits jumped out of a sticky Lee mould .
Once a good mould is broken in you wont have to use anything ... it's just getting that new mould all broken in that tricky ... Keep Casting with it and soon it will be doing right .
Also make sure you're holding your mouth right when casting ;)
Gary

[justindad]

If you must use some kind of mould release then use a spray on dry lubricant that contains Micro Teflon particles (PTFE) in it . The Teflon film doesn't contaminate and being teflon ... nothing sticks !

I am getting some sticking in the molds. Does it matter what sort of liquid is carrying the Teflon?

I found this: https://www.modeltrainstuff.com/Labelle-134-Micro-Fine-Teflon-Dry-Lubricant/?groove_ppc_id=351110887&msclkid=d18103c4c8451d9b75fe6391d2db0216&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping_All_Products&utm_term=4574793006850976&utm_content=All%20Products

[Land Owner]

Do you leave the ashes from sawdust on top of your pot while casting?
You bet I do. Leaving it there to smolder increases the flux (stirring without stirring) of tin and alloy constituents to help them remain distributed rather than some (like tin) disassociating by cooling at the surface of the pot where the temperature is lower. The sawdust smolders, and if I have included any from resin soaked pine, it smells nice. Crayons used as flux smell nice too. Pick those up from ANY restaurant that serves kids. They toss them but they're great for flux.

[Burnt Fingers]

Teflon decays into a toxic fume at around 450°. Personally I would avoid Teflon on my molds.

I've smoked numerous molds and never had a problem.

[popper]

stearic acid flakes for fluxing - why? Cheap SS isn't acid resistant. The pot will turn brown and 'rust' - which you scrape off - no - not rust but oxide alloy. Just use bees wax or candle wax. I tried the sawdust thing, got lots in the bullets I cast - ugg. Get the wax to melt only, stir a lot. Then turn up the heat and get it to burn. Basically floating the junk to the top where the wax captures it. Burning then 'reduces' any good part of the alloy into the melt and burns off 'consumable' stuff. Left over gets skimmed. Get your alloy to 720F, mould to 400F and start casting. Sprue plate (alum. mould) is hardest to get hot but will cool slowest. Sprue will go through 2 color changes, first is dull, second is whitish. Cut on 2nd. Invert the mould and tap the handle bolt with something hard to knock bullets free. Close the plate when mould is inverted, flip upright and pour again. Repeat. Lube plate pin and handle bolt (+ mould attach bolts on the handle) with 2 stroke oil, you get a feel for it after a while. Just some (not dripping) oil on q-tip, dabbed on TOP of the bolt. I use a pencil, scribble heavy on the plate bottom and mould top at the pin for plate lube. Do NOT use AC eco oil - it hardens and you never get it off.

[Krag 1901]

I have an new 314299 Lyman iron mold, how much break in should I expect? I've been casting with Lee Alum molds and never had an Iron mold. The only problems I've had was weight variations, once the molds are up to temp.

[justindad]

stearic acid flakes for fluxing - why?

The stearic acid as flux began because I had some I wasn’t using. I have switched to plain wax. I will keep using sawdust, but only slide it over the top of the lead, not pushing it down while I stir. Pushing down resulted in a lot of debris down in the pot, and clogged my nozzle. The sawdust grabs objects the wax won’t.
*
I left a skin of wax on top of the molten lead while casting today. It lasted 45 minutes or so, before completely burning away. When I shut the pot down, I let some wax melt over the top surface of the lead as a overnight protectant. Last time I left my pot full, the lead pulled away from the walls of the pot and I think some rust stated in the gaps, so now the surface is coated. The coating will burn and flux at start-up tomorrow. Hopefully it works out as well as I hope.
*
If I ignore the first casting, my boolits today weighed 126.3 +/-0.5 grains.


Lube plate pin and handle bolt (+ mould attach bolts on the handle) with 2 stroke oil, you get a feel for it after a while. Just some (not dripping) oil on q-tip, dabbed on TOP of the bolt.
Do these get sticky after a while?

[justindad]

I made one casting that turned out frosty (mold temp pre-warmed to 475F). I pan lubed and sized with the Lee sizing die. I found that half of each side of the parting line was not sized, as if the two sides of the mold are not properly aligned.
Is this an issue with the mold, or me?
*
These two pictures show the same boolit rotated 180 degrees. Material being swaged/removed on the right side of the parting line for both of these is what makes me think the two mold halves are misaligned.
280066280067

[Elmer Fudd]

I made one casting that turned out frosty (mold temp pre-warmed to 475F). I pan lubed and sized with the Lee sizing die. I found that half of each side of the parting line was not sized, as if the two sides of the mold are not properly aligned.
Is this an issue with the mold, or me?
*
These two pictures show the same boolit rotated 180 degrees. Material being swaged/removed on the right side of the parting line for both of these is what makes me think the two mold halves are misaligned.
280066280067

This is you. Cross your middle toes with the ones to the outside. And flip your tongue over inside your mouth.

[onelight]

How many did you cast ? Were they all like that ? Did you preheat the mold laying on a hot plate ?

[justindad]

How many did you cast ? Were they all like that ? Did you preheat the mold laying on a hot plate ?
I casted 30 pieces. I let the mold get a little extra hot on the last set, and only that set came out frosted. I’m preheating with a toaster oven, which is crazy slow. I’ll try a propane stove & pan as a free hot plate next time.
*
I think I can see eccentricity on the samples that are not frosted, but the eccentricity isn’t quite as visible without the frosting.
*
I understand how to get rid of the frosting, but the eccentricity is what I don’t know how to fix.

[onelight]

My questions were wondering if the mold was heated unevenly and if that could cause that . If uneven heat did that then it might go away after casting a bit and had a chance to heat evenly not that I know heating uneven would cause that . It may be a bad mold .
Looking forward to hearing other comments .

[justindad]

My questions were wondering if the mold was heated unevenly and if that could cause that . If uneven heat did that then it might go away after casting a bit and had a chance to heat evenly not that I know heating uneven would cause that . It may be a bad mold .
Looking forward to hearing other comments .
The mold got extra hot for these frosty samples because I had to divert my attention while casting. That plus the fact that I am using a slow oven as a preheater should result in a consistent temperature across the mold.

[whisler]

What mold are you using? If it is a Lee 2 cavity with the horizontal alignment pins, they can get out of alignment if not closed just right. Try setting the open mold on a flat surface and closing it while in contact with the surface if it is that type of lee mold.

[Land Owner]

Placing the boolit in the lube-sizer "off axis" (not vertical) can and will swage material from each side of the boolit's driving band - though opposite in position and not like that single boolit rotated 180*.

Is your nose punch correct? Flat nose punch - right? Is it well seated and locked down in the lube-sizer?

Your mold might not be circular/cylindrical. It may be warped, elliptical, and out of round (exaggerated dotted line being removed by lube-sizer [solid circle]).

https://i.postimg.cc/tRmK417J/Elliptical-Off-Axis.jpg

[LATE NOTE: I see it is a new mold (358-124-TC-R4 5 Cavity PB from NOE). I don't know how all 5 cavities could be warped - maybe, but probably not. I cannot get my mind around the SAME BOOLIT pictured 180* rotated above and the DRAMATIC cut off "ramp" right at the mold line exactly across the mold diameter!

too weird]

https://i.postimg.cc/NfczM1Bg/Elliptical-weird.jpg

Frosty boolits are indicative of the melt being too hot, the mold being too hot, or both! Cool it down a bit. Don't fuss over the pre-heat temperature. Dip the mold in the melt until "hot enough" that it "sloughs" the alloy. Dip the spru plate as well.

[justindad]

I haven’t had a chance to cast again to try and fix the issue, but these sketches describe what I believe is the case. Here are measurements from three parts cast on the same day:
A = 0.3581”, 0.3586”, 0.3586”
B = 0.3604”, 0.3597”, 0.3598”
C = 0.3568”, 0.3575”, 0.0.3575”
Measurements taken with a Starrett micrometer. The positions of B & C are held by eye, so the 15 degree shift from the parting line is variable.

I’m concerned this >0.002” eccentricity will cause leading of my barrel.

280105280106

[justindad]

It’s the mold. Back in the shop now, and the two mold halves have a bit of play when put together. I’ll call NOE tomorrow and see if this is within tolerance.

[onelight]

I made one casting that turned out frosty (mold temp pre-warmed to 475F). I pan lubed and sized with the Lee sizing die. I found that half of each side of the parting line was not sized, as if the two sides of the mold are not properly aligned.
Is this an issue with the mold, or me?
*
These two pictures show the same boolit rotated 180 degrees. Material being swaged/removed on the right side of the parting line for both of these is what makes me think the two mold halves are misaligned.
280066280067

Do you by chance have a picture of one of those just as it dropped from mold with no sizing or any other cleanup ?

[RogerDat]

I'm wondering about cleaning. I once forgot to use brake clean followed by soap and water on a new mold and the residue of oil from manufacturing created all sorts of issues. Including bubble like pitting that reminded me of what one gets when using a muffin tin with non-stick coating that off gasses until it gets properly burned off by repeated filling and dumping ingots. Lot of little pits like tiny bubbles had popped.

If one is unsure of mold temperature being "right" one can always try dipping a corner of mold into molten lead, in a short time mold will probably be too hot, then cast a few with long wait times for sprue to cool. On the way down to a good casting temperature one will have eliminated too cold a mold because the thing started at too hot.

Foreign substances can tend to bubble as they boil under the hot lead was my first thought when I heard the defect described as "rough". As to the question of sticky with pictures of defects with cause and cure would probably be useful.

[RogerDat]

I have sometimes wondered if I use too much pressure on long multi cavity molds if I might cause some shifting of the mold block alignment due to pressure in the center creating a bit of a shift due to bowing or because the molds are being pressed hard all the way in one direction on the alignment pins. I have a 5 cavity 38/357 mold that will show a faint mold seam when I squeeze the handles too hard, not there if I relax a bit. I think the heavier mold causes me to use a heavy grip.

[justindad]

Do you by chance have a picture of one of those just as it dropped from mold with no sizing or any other cleanup ?

When I hold the two mold halves together and shimmy them back & forth, they make an audible rattle. I have another mold for the .45, and it has zero play in the alignment pins.

This picture is of the exact three boolits used in my eccentricity measurements above. These have not been sized.
280124

[huntnman]

What I see is your mold halves are not in alignment. .003 off in your drawing. Bottom shifted to the right top shifted to the left. The parting line on the boolit shows one side of drive band sized more than the other. My guess if it is only one cavity doing this it is a milling error, OUT OF ROUND, all cavity's probably alignment pins. YMMV
NOT A PROFESHANL

[FLINTNFIRE]

I do not float my mold in the pot , put it on a hot plate or on top of pot while it is heating , but do not get mold over heated or you can warp it as to smoking the mold I have and Lee and NOE both advise it , it is up to you if you do or not it has not hurt any aluminum mold I have done it to .

Frosty is hot melt and a hot mold , back it off a bit , are you measuring temp. ? As to what temp. your thermometer is not always right PID on my pro melt 2 has me running a higher temp. then some are saying to use to keep spout from freezing and alloying flowing and I am not getting frosty bullets , used a pot for a long time with no temp. measurement , the alloy you are using will tell you what it likes and the bullets will show you , wrinkled , voids, rounded bases and bands rounded will tell you cold alloy contamination incomplete pour or not enough sprue puddle to cold of melt or to hot , mold to cold or to hot , Cast more at a session see if it starts to run better , when I am having a mold with issues , I find if I keep going and dropping bullets to check every few casts until they start looking like I want, if they do not look right I adjust temp of melt , temp of mold and keep casting after a hour see how they look set mold on hot plate sort bullets while pot is melting more alloy and coming up to temp .

If you have to many rejects , are the rejects consistent of the same defect or not and adjust casting technique from there . Practice does make one better at this .

[onelight]

I agree with huntnman , for some reason the mold does not appear to be closing in alignment .
Both mold faces should be clean of lead as well as the alignment pins and holes and the blocks should be loose float on the handles , so the mold can self align when the mold is closed. But if any of these issues are there I usually see flashing around the mold joint on the bullet when it drops , if the mold and lead are up to temp if they are not hot enough the lead may set up before it can flow between the mold halves to give you the flashing so the problem is less obvious .
Wish I had something more to offer.

[oley55]

When I hold the two mold halves together and shimmy them back & forth, they make an audible rattle. I have another mold for the .45, and it has zero play in the alignment pins.

This picture is of the exact three boolits used in my eccentricity measurements above. These have not been sized.
280124

I am a million bullets from qualifying as an expert on most anything cast bullet related, but what you described (red text) sounds like the alignment pin/s got bumped or were installed too deep. Not familiar with NOE molds, but I'd think they can be bumped out a bit. I'd also think you could drive yourself nuts (and possibly screw up the mold) chasing the pins in and out between too short and too long.

Waiting for more knowledgeable casters to shoot down or correct my observation. I sure wouldn't start pushing alignment pins around based only on my thoughts.

[Bird]

I agree with oley55. Had the same situation with a RCBS mold. I chased the pins in and out and managed to get the alignment better but not perfect. I sent them back to RCBS for adjustment and they came back perfect.
Accuracy of the bullet should not be affected, as the opposing balance will be equal.

[justindad]

The mold is going back to NOE.