New casts look like junk

[wlkjr]

I changed molds from a 233 grain to a 100 grain that I had used previously. I used up 800 bullets that I had cast a couple of years ago and coated with Hi-Tek. Decided to cast more of the 100 grainers to coat with Hi-Tek but they all look like trash. They all have some unfilled cracks down toward the nose. The base areas all are smooth. Usually the first 20 or so new casts will have some wrinkling but then smooth out. I just used the same batch of lead ingots last week to cast about 1500 233 grain bullets. I had no problem with those.
Today I switched to a different mold and can't get the bullets to fill out properly. These are small 100 grainers. Down toward the point there are some small areas that have voids like a crack. the base area looks really smooth. The lead I'm using is a combination of range scrap, wheel weights, lead bars of 50/50 lead-tin, and lead slugs from RMR. I've adjusted drop rate and temperature but nothing seems to help. Any ideas? I haven't had any problems before in the 4 years I've been casting. I'm casting on a Master Caster which is great by the way. I have inspected the molds very closely but don't see anything noticeable. I switched back to the 233 grain mold and they too now look like junk with grooves in them. Fill out problem or bad lead?

[wlkjr]

I have emptied my melting pot completely, taken a small stainless steel brush and brushed it out, wiped the inside with acetone, and vacuumed it out. I have a different batch of lead in it now melting. Will see how it reacts. I'm thinking it;s something to do with the new batch of range scrap I just bought. I dipped the suspect lead out of the pot and poured it into a Lee aluminum ingot mold that I have used in the past. Some of those ingots have the same funny look to them. Guess this will give me a clue. I hope it's not the lead because I just bought 200 pounds of this new batch.

[No_1]

What temperature is/was your melt?

[wlkjr]

What temperature is/was your melt?

653 initially which is what has always worked for me. I bumped it up to about 680 but that didn't change anything.

[Conditor22]

there are several different Master Casters, which one are you referring to?

653° seems cold except for a harder alloy. I usually start at 680-720° -- 750 for pure.

the first thing I do when I get bad boolits is clean the mold(s) thoroughly,

Pictures would help,

there are some people out there shooting Zinc boolits, if more people start/keep doing this using range scrap could become problematic.

smaller cavity molds will take longer to heat up.

I take it you smelt and flux well everything that goes into the pot.

[wlkjr]

I have the small benchtop Master Caster with a 40# pot. All my lead is clean when I put it in the pot. I do flux it some of the white compound from Magma. Only a little slag after fluxing. Initially I tried pouring at around 720 degrees but found that to be too hot, so I started lowering it. I have cast over 1000 pounds and never had a problem before. I have cleaned my molds with the spray that comes with the unit. I just cast about 2000 9mm and 1500 .45acp the last couple of weeks. I'll give it a go again tomorrow. I have a couple of pics if I can figure out how to attach.

[charlie b]

Select 'Go Advanced' below.

Then scroll down to 'Manage Attachments'. You can upload pictures there and then attach to threads.

[wlkjr]

finally

[The Dar]

I'm not an expert, but it looks like your bullets were cast in "layers". Was your flow rate fast enough?

[wlkjr]

I'm not an expert, but it looks like your bullets were cast in "layers". Was your flow rate fast enough?

It was pretty fast. I'm trying different things again tomorrow. Sure hope it's not that 200# of lead I bought last week. That would really suck. The lead is really clean and the ingots look good.

[468]

Also, not being an expert, I wonder if running the mold a bit hotter would help...

[sigep1764]

That looks like a cold mold/colt melt. Crank it up to 700 or 720

[wlkjr]

That looks like a cold mold/colt melt. Crank it up to 700 or 720
I will try that tomorrow. Maybe this new alloy needs a much hotter temp. I went up to 680 buy that might not be hot enough. Hopefully, tomorrow will be much better than today was.

[Dusty Bannister]

It does look like a cold and slow pour. Did you clear the nozzle or just clean out the pot? Do you cast in a controlled temperature area? With the experience you have with this machine, you would likely have noticed any change in casting location or temperature. Cast hot and then lower the temperature. I get the impression this is one of the manually operated machines so hot and fast and then when getting good bullets slow down or lower the temp or both. You said that 720 was too hot, why did you conclude that?

I cast most alloys except pure lead at about 720 degrees. Pure lead is closer to 800 degrees. A satin looking surface is good, galvanized is too hot. These shine so a bit cold. When you flux, introduce some vertical movement in the pot. That will bring up any suspended dust in the melt. Higher melt temperatures will create a bit more dross but that can be reduced back into the melt.

[44Blam]

The pour is interesting, when you start casting 4-500 grain boolits you gotta let that lead flow FAST. Also with those big boolits, I find that I am 100% (once the mold is up to temp) if I pour straight down the hole and don't hit the sprue. But if I hit the sprue with the stream I get occasional rejects.

But what you showed does look like a slow pour...

[No_1]

Every alloy is different. I like frosty looking boolits so with my 2 alloys (96/4 & 94/4/2) I set my PID at 700 degrees then adjust the melt +/- depending on how the boolits look when they come out. In the dead of summer when it’s 95+ degrees I run the melt at the low end of 700. When it cooler I find I must turn the temp up for my boolits come out looking they way I like them.


653 initially which is what has always worked for me. I bumped it up to about 680 but that didn't change anything.

[mehavey]

Three questions:
- Do you preheat (https://s15.postimg.cc/n7t2rmxtn/Hotplate.jpg) ?
- Do you have/are you using a thermometer? (I'm suspecting low temp, regardless of dial indicator)
- Does same problem occur if/when you use a dipper (https://images-na.ssl-images-amazon.com/images/I/410GrplDbLL._AC_SX425_.jpg) ?

[SSGOldfart]

Temp is to cool,maybe your pot isn't holding steady temp?? Could it be a little age with the heating element.

[Wayne Smith]

Does your machine have any ability to pre-heat the molds? However if you are seeing problems throughout a casting session this is not likely the problem. I can't add anything other then this to what is above, not knowing your machine.

[wlkjr]

OK. Here is the latest with a little background. I cast in my workshop which is heated to 66 degrees. All my lead that I am presently using is in the shop, so it should be 66 degrees also.
I bumped up my temperature to 720 degrees from 680 in 10 degree increments. I have cleaned the mold with denatured alcohol--no change. Cleaned the mold again using brake cleaner--no change. I still get the vertical lines in my cast. I adjusted the drop, which takes about half a second to fill the mold. It is a two cavity mold and today I'm using the 100 grain mold from Accurate. I have used this mold before with great results. I have once again emptied the pot and have dumped in some of the lead slugs I bought from RMR. This is the leftover they sell when making their slugs for their bullets. It is presently melting in the pot. It gets kinda smokey but I have an exhaust fan in the window right in front of the caster, so most of the smoke is drawn out the window. I made a short video and another picture if I can figure out how to attach.

[wlkjr]

This is the latest cast. Can't attach a video that I'm aware of.

[mehavey]

That cast looks cold -- alloy and/or mould.

- Do you have a thermometer ?

[45DUDE]

You might try putting the mold on a heat plate for an hour. I don't clean my molds or use any chemical on them and keep them in a control temperature. I cast at around 800 degrees. Like others it looks like a slow pour with the mold not hot enough. I sprayed a mold with wd 40 one time and put it up. The next time I used it the bullets looked bad. It took about 100 castings for the boolits to start to look good. I think the wd 40 soaked into the mold. Anyway that same mold is ready when I place it on my pot to heat up the lead. My lead does not smoke any unless I flux it.

[fredj338]

653 initially which is what has always worked for me. I bumped it up to about 680 but that didn't change anything.

Smaller bullets, go hotter. I cast up to 750deg with HP molds or molds that have other fill-out issue. Clean & preheat the mold & turn that pot up.

[wlkjr]

I bumped my temp up to 735 and changed to a different mold. These are not hand held molds so you can't put them on a hot plate. I do however preheat them while they on the machine with a propane torch. I finally got a good pour with a 95 grain mold. So I switched back to my 100 grain mold and heated with the torch. This time I shot the flame down into the cavity. If there was anything in the mold the torch burned it out. Finally getting a nice looking bullet. Apparently this new lead requires a substantially hotter temp. My pour rate is about a half a second to fill the mold. I modified my caster to use a pneumatic cylinder to operate the pour handle, which is operated by a joystick. I can also operate the release handle by the same method or use the handle manually. Thanks for all the tips. I certainly wouldn't have thought I would need 735 degrees to get a good bullet. Guess I'm still learning as I go. Under 700 has always worked for me before, but I guess this new batch of lead requires much hotter temps. My mixture is a kind of bastard mix, nothing specific, a mix of clean range scrap ingots, wheel weight ingots, a handful of linotype and a half a bar of 50/50 solder-tin. This strange mix has always worked out great and coats with HI_TEK to make a very nice shooting bullet.

[Conditor22]

How cold is the room your casting in?

The sprue looks like your cutting it too soon or the countersink in your sprue plate doesn't go to a sharp edge.

the picture looks like you had cool lead in the cavity before the hot lead finished filling it (this usually happens when lead slops from one cavity to another when you pouring and cools off before you pour the next cavity but this can't happen on your automatic caster. my guess is cool mold and the lead is cooling in the spouts on the caster.


Harder lead ie. 15-16 bhn melts at a lower temperature

softer lead needs a higher temperature. Pure needs over 750°

you might have to fun smaller boolits faster to keep the molds hot.

those boolits look close, maybe a few ounces of tin would help with fill out.

[mehavey]

Again the question -- WLKJR: are you running an actual thermometer ?

[wlkjr]

Again the question -- WLKJR: are you running an actual thermometer ?

I have a pid controller, so I suppose I have a thermocouple and not an actual thermometer.

[wlkjr]

My shop is 20x40 and well insulated. I keep the heater on and it stays around 66 degrees. My lead supply is housed within the shop, so it is room temperature. The sprue cutter is not sharp, kinda dull like me.

[mehavey]

I have a thermocouple and not an actual thermometer.That works....

[Cosmic_Charlie]

Maybe add some more tin.

[MOA]

I do from 22 cal to 45 on my MC. Always seem to get better boolits around 700 up to almost 800 degrees. The smaller calibers seem to need hotter temps to fill out. It looks like your running the bevel base molds from Magma, so the composition of the iron they use may be different than other mfg molds. I have one mold for my 9.3 that was cut by NEI back in 2012 using a blank block from Magma. All the rest of my molds are either Lyman or RCBS that I had converted by Magma to run on the MC. Their blocks might need more heat also. I also use a thermometer from Roto Metals in the pot. I have one of their PID's but haven't had the chance to hook it up yet.

[Conditor22]

Are the holes in the sprue plate in the troublesome molds the same size as the ones in "good molds"?

[wlkjr]

Are the holes in the sprue plate in the troublesome molds the same size as the ones in "good molds"?

Yes. All my sprue cutters are the same size from the 95 grain up to the 233 grain. I have corrected the problem with the knowledge and help of the good folks here. I cast about 1200 of the 100 grain bullets this evening. All of them look really good and completely smooth with no voids whatsoever. Thanks to all.