boolits come out looking like i have dirt in my mold

[vernb]

I'm not real new to casting. I've got 4 different molds all Lee. My 452 300 rnfp gc keeps dropping bullets that almost look porous on one side. It looks like it would have dirt in one half of the mold. It's always in the lube groove and driving bands some boolits look perfect but it might just be one cavity with the problem. I leemented the mold with no change and I've cleaned it with brake clean and a toothbrush . No luck . Looking at the mold I don't see anything wrong

[huntnman]

Are you using a bottom pore pot, fluxing, removing all slag from melt and pot? I had similar problems caused by me melting dirty lead in casting pot. The residual gunk that stuck in my pot causing the problem, which was worse in larger weight boolits.

[Calamity Jake]

^^^^^^^^^There you go, dirt in the melt.
Flux the bogebers out of it and try again.

[vernb]

I use a bottom pour. I flux any time I add lead ingots and usually when throwing sprues in. I flux with saw dust and candle wax and I leave the sawdust on top as a barrier. This is the only mold it happens to. Although this is the largest mold I have

[docone31]

Two issues. Heat the mold, and there will be scale on the bottom of the pot. You will need to scrape with a long screwdriver to break up the chunks. They will then float to the top. You will be suprised at the size of the scale. I suspect it is contaminating the pours.

[osteodoc08]

Drain your entire pot and clean it if you haven't done so lately. I used red oak for a while and ended up with similar. Cleaning the pot really well remedied the issue. Now I only use beeswax in the cast pot. Still use red oak (love the smell) with old honey comb from my beekeeper friend to flux and reduce when making ingots

[bangerjim]

Yes.........heat mold to CASTING TEMP on an electric hotplate. Completely clean you pot. I have not dumped mine in.....forever.....but I do not get garbage in my boolits. If I did, the first thing I would do is dump and clean VERY well. Cleaning should help.

Also I never use sawdust in my casting pots. Always a pea sized hunk of beeswax ONLY......not candle or paraffin wax. (stinks and flares up to easily). If you KNOW your feed ingots are 110% clean, you only need to reduce the Sn back into the mix when casting. Fluxing with sawdust is for removing gunk from melting dirty lead and filthy WW's in your big re-melting pot. A tiny hunk of beeswax will turn your pot's surface mirror shiny by reducing all the Sn back into your lead. Just stir it in and skim. Sn is our friend!

banger

[JonB_in_Glencoe]

I'm not real new to casting. I've got 4 different molds all Lee. My 452 300 rnfp gc keeps dropping bullets that almost look porous on one side. It looks like it would have dirt in one half of the mold. It's always in the lube groove and driving bands some boolits look perfect but it might just be one cavity with the problem. I leemented the mold with no change and I've cleaned it with brake clean and a toothbrush . No luck . Looking at the mold I don't see anything wrong
You have been given lots of advice about cleaning the pot and it's always a good thing to have clean alloy going into your mold...BUT...

Have you measured the diameter of your boolits?
Do those with a porous spot, measure a little smaller, when measuring "on" that spot ?
If so, I call that shrinkage, others call it poor fillout.
What is happening is, as the alloy freezes and occupies less volume, it will want to "pull" alloy from the molten sprue puddle. If the molten sprue puddle freezes first, the boolit will shrink or not fillout in the hottest part of the mold, typically it's in the middle, about where you are describing the location you are having your problem.

My suggestion, pour as large of a sprue puddle as possible.

http://castboolits.gunloads.com/showthread.php?258255-cast-boolit-flaws-due-to-shrinkage-announcing-the-solution-(for-me-anyway)

[mdi]

I stir with a wooden "shim" roughly the size of a paint stirring stick (I found rough cut shims , 1"x12"x 3/8" thick that tapers to a point, at my local hardware for less than $5.00 per bundle of 18). When I flux or just stir, I like to scrape the sided and bottom of the pot, and I like to stir several times while casting. Haven't had any rough, porous looking bullets in a while.

[Yodogsandman]

The first time I tried an aluminum mold, I had a similar problem with small porosity holes on the boolits from just one side of the mold. No specks of dirt could be seen. I found that the mold was heating up too much and I had to leave the mold open for about 15-20 seconds between casts and slow my cadence. I don't use a fan so, I even blew on the inside of the mold between casts to cool it faster. I still left a big sprue puddle to keep the sprue hot. The boolits cast perfect after that discovery! Easy to find out if you're having the same problem, too.

[reloader28]

I agree that the mold is too hot. Let it cool a touch. Sometimes I have to turn down the pot heat a little and cast a little slower when I have that problem.

[vernb]

I was leaning toward too hot myself. I don't have problems with my 148 252 and 124 grain molds but almost always with my 300. The sprue plate tends to get so hot I have to slow down quite a bit. Also this is the only bullet I run straight ww water dropped with 2 percent tin . I would be hard pressed to give up sawdust as flux since it has been highly recommended by Glenn frixxel and has worked well for me . I always scrape my pot with a stainless spoon when fluxing and have only had it plug up once when I let it run to low. That was probably500 boolits ago when I emptied cleaned and boiled the pot

[vernb]

124576

[vernb]

124578

[vernb]

This is all pics of one boolit

[44man]

I empty my pot often as I test alloys and no matter what I flux with there is always some black looking dust in the bottom. It refuses to float.