315" C.B.E mold temperature problem?

[multifasciatus]

Hi


Trying out my new 303 two cavity mold. Im using ww in my Lee production pot.
Im having a hard time finding the right temperature.
The bullets got either wrinkled or frosted,not exactly frosted but a dull shine.
Soot did help fillout,no soot i got wrinkled bullets.
Did flux (Marwelux), used a hotplate,bottom pour-ladel fill,
Have a suspection my mold is not gaining enough temerature.
Have only been smelting large cal black powder(pure lead )bullets before.
Wheel weights is a different beast.
Anyone?

[JeffinNZ]

A dull shine is all you will get from WW metal. It won't be shiney. Sounds fine to me.

[454PB]

You need to control the mould temperature, the pot temperature is secondary. You can either adjust casting rate to do this (slow down if it's too hot, speed up if it's too cold), or you can use the method I use. I use a wet cloth in a cake pan to cool the mould when it gets too hot. Just touch the bottom of the filled mould to the wet cloth for a second, it hurts nothing and brings the temperature down quickly.

Another method I use a lot with Lee and other moulds is to use two moulds at a time to slow the cadence.

[Norbrat]

You need to control the mould temperature, the pot temperature is secondary. You can either adjust casting rate to do this (slow down if it's too hot, speed up if it's too cold), or you can use the method I use. I use a wet cloth in a cake pan to cool the mould when it gets too hot. Just touch the bottom of the filled mould to the wet cloth for a second, it hurts nothing and brings the temperature down quickly.

Another method I use a lot with Lee and other moulds is to use two moulds at a time to slow the cadence.

CBE moulds are brass and really don't suffer too much from overheating. They also have a nice thick steel sprue plate which helps to maintain an even temp.

My boolits from wheelweights always look a bit frosty, but they work fine.

I find that once the CBE mould is up to temp, I just cast at an even pace, with the sprue puddle taking maybe 3-5 seconds to set before I open the sprue plate.

BTW, what do you mean by "bottom pour ladle fill"? Did you fill the ladle from the bottom, then used the ladle to pour into the mould?

I bottom pour with the mould hard up under the spout, then drop the mould a little to pour a puddle on the sprue plate, then move on to the next cavity and repeat. Seems to work for me.

[runfiverun]

the satin look is what i strive for in my boolits.
if shiney the mold is too cold.
if the boolits form white areas thats frosting, and the mold is too hot,and those areas are usually rounded off.
you should need no soot in the mold, it will act as a heat barrier.
and don't use the marvelux it will suck what little tin you have in the ww alloy into it.

brass is about halfway between aluminum and steel in how they like to be run,temp,alloy heat and be filled.

[454PB]

To clarify, I also strive for lightly frosted boolits. I only use the mould cooling method when it's obvious that the mould is overheating (I'm casting too fast). While it's less of a problem with larger, multi-cavity moulds, it can and will happen with any of them if they are used fast enough. When I'm using a single cavity that casts a large boolit, it is almost required.

[geargnasher]

Satin wheel weight boolits = good at my house.

The mould temperature is the important thing to try to control, since it affects the "sheen", wrinkes, and overall fillout. Keep the pot temperature about 100 or so degrees (F.) hotter than the point that the alloy is fully liquid and it will be fine. Wheel weights like anything from 650-725 depending on the exact composition and whether or not you added any tin (1% is plenty for most wheel weight metals). Tin lowers the melt point a few degrees.

Speaking of tin, that Marvakrap stuff you have there is really, really good at removing tin from boolit casting alloys, one of the reasons I don't touch the stuff. It is an excellent flux, removing many impurities from the mix (even the ones that don't matter, and some that we WANT in there, like tin), but it's tendency to absorb water and remove tin nix it for me, not to mention the mess it makes.

Tin is important to help your boolits fill out well, and also to prevent "antimony wash" in your gunbarrels. Only a trace of tin is necessary, anything more than 1.5-2% is a waste for the majority of our boolit casting needs. Tin helps fillout by making the alloy more "liquid", or flow better because it flash-oxidizes on the molten stream going into your mould and keeps the lead from oxidizing. Lead surface oxide skin is tougher than tin, so it prevents the alloy from flowing as well compared to how it does with a percent or two of tin. To preserve tin in your alloy, never heat it above 750 degrees F, and never use Marvellux or any kind of borate flux. Instead, use a few spoonfulls of pine sawdust or chainsaw shavings and stir the metal well with a stick. Just let the shavings smolder on top of the lead if you bottom pour, otherwise light the smoke and skim the ash when it burns out. Stirring the alloy and scraping the sides while it chars really helps, and this both cleans impurities from the melt and sets up a reduction/oxidation reaction that chemically reverts oxidized scum on top of the metal to clean, shiny alloy.

Gear

[multifasciatus]

Thanx guys,great info.
Norbrat (i tried ladle and bottom pour)
Bye bye Marvelux
Still a bit confused about not smoking my brass mold,seems like i get mutch bette fillout when i do.
Still ,not two molds are alike i guess.

[454PB]

I know Marvelux is disliked by many on this forum, but where did the idea that it removes tin from the alloy come from?

Yes, it is hygroscopic, and takes some caution in use, but we should all be preheating our dipping/stirring tools anyway.

Sorry, I don't buy this idea until I see an analysis that proves it removes anymore tin than any other flux. I've been using Marvelux for 30 years, along with other fluxing agents. I see NO difference in the results.

[geargnasher]

454PB: A copy/paste of an excerpt from Glen Fryxell's article on fluxing lead boolit alloys.

"Some of the commercial bullet fluxes are formulations that have the advantage of generating virtually no smoke or odor (in contrast to the waxes just discussed). These formulations are commonly based on borax, or other boric acid derivatives. The way these commercial fluxes work is to combine with the oxidized components of the alloy (including any oxidized tin) and form an insoluble molten borate glass, which collects on top of the melt as a dark molten crust. This process is smoke-free and cleans the alloy very effectively, but the dark molten crust must be removed to prevent inclusions in the bullets. Unfortunately, any oxidized tin is also removed in this process. Relatively little of these borate-based fluxes is needed to effectively clean up bullet metal (only about half a teaspoon is needed for a 10 lb pot), but too much can cause problems by generating excessive amounts of this molasses-like glass that sticks to the ladle and lead-pot, and can cause inclusions if not removed."

The thing is, tin oxidizes more rapidly than most other metals in boolit alloy, and because tin is the formost oxide on the surface of sprues, boolits, ingots, etc., and once oxidized, tin won't melt back in, then the scum on top of the pot has a high concentration of tin oxide when you go to "flux" it. Sawdust reduces this oxide back to elemental metal while Marvelux removes it. You might as well just skim it all off and toss it rather than using any sort of flux or reducant and skip the expense and mess that stuff makes.

Sawdust pulls out what we don't want, saves what we do want, and is free. That's why I use it.

Gear

[454PB]

I have a lot of respect for Glen and his research writings, but I can't agree with this. Yes, a grey sludge forms when Marvelux is used, but I leave it in place after stirring the mix. Within a few minutes, it reduces to the typical layer of dross seen with any other flux. I always leave that layer on top, even when ladle casting. I have no slag inclusion problems. After using this stuff for 30 years, I think I would see any negative effects, and I haven't.

As previously stated, I know the use of Marvelux and the similar Frankford Arsenal flux is not popular. I've even seen it stated that it's propensity to collect moisture will rust out the melting pots.....that's untrue as well, one of my Lee pots has been used with Marvelux flux for full 30 years and is just fine.

I'll continue to use it for my indoor casting.

[geargnasher]

The chemistry of the process doesn't care if you agree or not, it just is. I'm not trying to talk you out of using the stuff if you're happy with your results, but the decrease of the dross after adding Marvelux is the issue I have with it: It's absorbing the stuff thatI want to keep in my boolits. I think the only reason the stuff is still around is because it does absorb a lot of impurities that impair fillout, so the alloy can still cast ok even with lowered tin content.

Gear

[felix]

Ian, that is the reason! Marvelux is a common salt, the name of which I forgot. ... felix

[runfiverun]

it's basically borax or airc boric, heck, i ain't even gonna try, sumthin nitrate- tride.
a light coating of it does form a nice glassy covering and is pretty useful if casting at higher temperatures.
you lose less tin with the covering than it draws out.
i have also used it to flux antimony into a tin rich alloy.