Textured surface on boolits?

[brewer12345]

I was casting with a new to me Lyman 3112991 I bought used. The mold looked OK, but it produced boolits with an odd surface texture I have never seen before (see pic). Is this rust in the cavities? Best course of action?

I will powder coat and gas check these and see if they shoot. Since I cast them out of pretty hard stuff (about half lino, half SOWW), they are only for target use so if they don't shoot well it is not a huge deal.

261424

[Geezer in NH]

Junk in alloy, to cold of mold and alloy as the corners don't look sharp to me.

[brewer12345]

Mold was preheated and alloy was 750+. The same pot of alloy cast a bunch of boolits from another mold that came out fine.

[bangerjim]

Oil will cause that............mabe ONE or TWO times...........not over and over. The oil burns out/is dispersed after only a couple pours. Clean & scrubbing & scrubbing & cleaning a mold is a total waste of time.

It still looks like a temp or poor alloy problem. How much Sn do you have in there? Some molds love 2-3% for good clean pours. I always use 2% in the mix of whatever I am making.

And are you sure you are using REAL lino? Did you melt it from actual"lines-of-type" in it's native format, or use some ingot-thing you bought from somewhere that claims it is lino???????

Try it. Let us know if Sn solves your problems. Every mold is different~!

PC'ing will cover up most of those divots and those slugs should shoot just fine! (They will shoot just fine without the PC) After all, its' only target practice, right?

banger

[brewer12345]

Oil will cause that............mabe ONE or TWO times...........not over and over. The oil burns out/is dispersed after only a couple pours. Clean & scrubbing & scrubbing & cleaning a mold is a total waste of time.

It still looks like a temp or poor alloy problem. How much Sn do you have in there? Some molds love 2-3% for good clean pours. I always use 2% in the mix of whatever I am making.

And are you sure you are using REAL lino? Did you melt it from actual"lines-of-type" in it's native format, or use some ingot-thing you bought from somewhere that claims it is lino???????

Try it. Let us know if Sn solves your problems. Every mold is different~!

PC'ing will cover up most of those divots and those slugs should shoot just fine! (They will shoot just fine without the PC) After all, its' only target practice, right?

banger

Yes, this was real lino. I cast with 3 other molds (including a Lee 2 banger that came apart after I got 30 keepers) and none of them look like this. I would guess the alloy was at least 2% tin. The other molds were all lee, a 6 banger 358-125, a 2 banger 309-113 and a 309-150 (which died). None of them threw boolits that look like the surface of the moon. I am not hugely worried about this mold tossing weird looking slugs, just curious what caused it. These are for playing around, as I will likely only get a muzzleloading deer tag this year and my 30 cal deer boolit is a 200 grain monster with a huge .19" meplat. I use partitions for elk since we hunt late season with wary animals and 200+ yard shots are typical.

[popper]

Yup, oil - probably silicon. Brake cleaner and scrub several times.

[brewer12345]

Scrub with what? Copper chore boy?

[Winger Ed.]

Scrub with what? Copper chore boy?

I wouldn't use anything that violent.
I've had good luck with a tooth brush, a Q-tip, or those plastic/nylon green kitchen scrubby pads from the grocery store.

[45-70 Chevroner]

I use Comet cleanser and a tooth brush, then rense good then clean with dish soap. Doing this even with a new mold gives me perfect boolits right from the start. My feeling is that your mold is just dirty.

[slim1836]

Lap your mold, that may solve it.
I’m no expert on this, just a suggestion.
Half the fun is figuring it out. Good luck.

Slim

[Conditor22]

the first thing is to clean the mold thoroughly. I use a toothbrush, hot water, and dawn dish soap. I usually scrub and rinse 3 of for times to assure a good clean.

If that doesn't work I would try polishing the cavities gently with glue boolits and fine polishing compound

[slim1836]

the first thing is to clean the mold thoroughly. I use a toothbrush, hot water, and dawn dish soap. I usually scrub and rinse 3 of for times to assure a good clean.

If that doesn't work I would try polishing the cavities gently with glue boolits and fine polishing compound

Another good use for glue boolit’s, thanks.

Slim

[tazman]

Personally, I would see how they shoot for you before I did anything to the mold.
Some of my best shooting boolits came from molds that dropped "textured" boolits.
Since you are going to coat and size them in any case, I don't see where the surface is important at all. The coating will smooth out the surface and the sizing will remove any blemishes on the sides.

[dangitgriff]

Golf balls have little dents for a reason.
I wonder if Tom over to Accurate could make me a mold with those little golf ball dents? [emoji848]

[mdi]

You should be able to see it the mold cavity is rough enough to produce bullets like that. When I want to get a mold really clean sometimes I'll make a paste out of Bar Keepers Friend or Comet and oil and lightly lap. More "abrasive" than dish soap, but not abrasive enough to change the bullet measurements. Have you sized any? If so was the sized portion smooth and shiny?

[country gent]

Make sure vent lines are clean and clear. trap air can cause that finish also. Experiment with temperature some, moulds are individuals and while some will cast at lower temps others need a little more. Try starting the pour with the mould slightly angled and straighten as it fills, Tr to get a "swirl" as it fills. I would try a cleaning it like this.
Pull blocks off the handles
stand up right in an old pan
cover with water and dish soap
set on stove burner and boil for 10 - 15 mins. This helps the soap to work and thins ant oils or materials helping to release them
With gloves scrub with a tooth brush over the pan.

Some moulds really need a extra vent groove added at the very top of the blocks. With a fine stone or sand paper backed by flat bar cut a .005-.010 X 45* on each top corner.

Pour and fill as fast as possible pouring as large a sprue as possible

[Burnt Fingers]

I have to agree with Geezer. Those boolits don't look right. All the corners are rounded off.

[gwpercle]

I have to agree with Geezer. Those boolits don't look right. All the corners are rounded off.
I have to agree with Burnt Fingers and Geezer ... Something is contaminated or the pot needs fluxing or the cavities got mould lube in them...something ain't right .
Drop back , start over with a clean mould , acetone and toothbrush , fluxed pot...sometimes things work better the next day ...don't know why...they just do .
Gary