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 ?
- 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 ?

[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.