Lead blocks pot spout

[schraubermani]

Hello everyone,

i am a Commercial bullet caster from Germany.
I run a Magma Mark 8 and a lead-pot for Hand casting.
I got 800lbs. in blocks made of range scrap lead.
The lead Looks Pretty clean if it is molten but it is plugging my spout.
First everything is ok, after 20min of casting the lead stream is becoming thinner and thinner.
So i have to clean the spout and the game Begins from the beginning.
I cast at About 700 Degrees, increasing the temperature does not make any difference..
I flux the molten lead in the pot, but the lead is evidently clean. No dirt coming up the Surface.

Maybe someone of you might have an idea what could couse my Trouble?

Thanks a lot and best regards,

Manuel

[JSnover]

Is it necessary to clean the spout by hand, or is it as simple as heating the spout to make it flow again?

[billyb]

If you have Zink in your alloy it can plug up your spout. had that experience.

[glockfan]

are you talking about the pot used for handcasting? if it's the case,which pot do you use?

i know my lee 4-20 may clog from time to time,all i have to do is screw in,unscrew repeatedly the rod adjusting the lead flow. ...and it doesn't happens really often. if your problem is recurrent,well,it's possible that you don't run the pot hot enough,or there's a too long gap between each pours.

your lead might also contains more unwanted stuff than what you think,like ZINC , while you stated your lead appears very clean,so it might be related to the flow rate, the gap between pours, or lead temp.

[schraubermani]

Thanks for your fast replies.
Unfortunately it is necessary to clean the spout by Hand, removing the orific-plate from a Mark8 when the machine is hot isn't a funny Thing to do.
I also had a suspicion, that there may be Zink in my alloy, but i do not have the typically zink-foam on the Surface of the molten lead, or just minimal.
But i wonder, why i cannot get the spout holes clean by heating the orific-plate of the machine up by a gas-torch.
O.K., the pouring holes are very small, about 0,06 Inch in Diameter.

Has anyone an idea, how i could remove the zink from the molten lead?

Best regards!

P.S. i am Talking about the Mark8 from Magma primarily

[Dusty Bannister]

JSnover gives you a clue. Since you have a lead pot for casting, you may want to consider bringing a pot of your casting alloy up to casting temp and then slowly lowering the temp until it starts to form a slush. If you have any copper crystals forming on the surface, that is probably what is happening at the nozzle of your casting machine as well. Excessive amounts of copper in the solution will start to come together at the cooler part of the melt, which will be on the surface or at the nozzle. An application of heat at the nozzle will cause the copper to go back into solution and free flowing returns.

You can either increase the casting temp to keep the copper in solution, or lower the temp and skim the copper crystals as they form. This does assume that copper is the issue. If you have access to an XRF scan, that will tell you what else you might have in the range scrap alloy. Dusty

[schraubermani]

Dear Dusty,

thanks a lot for your advice, i will try this.

Best regards,

[Rcmaveric]

I have to cast pretty hot. How hot have you tried to cast with? My normal casting temp is ar 900 to 950 degrees F.

I would confirm the zinc contamination before going that route. There are a lot of things that can can clog a pour spot. If i have my pot at 750 and the sprue plate touches the spout. It will stop my pour spout.

Sometime casting at two low of a temp with antominal lead will cause a slush phase similarly to a zinc slush. Other contaminations like copper can raise melt temps.

Sent from my SM-G925T using Tapatalk

[schraubermani]

Yes, i think i will try to heat up the orific-plate of the machine with a gas-torch to get the lead pouring better to evacuate the melting pot.
Then i will use lead from another Batch.
I think, that the range scrap lead was molten at much too high temperature and so the Zink/Copper/whatever did not go up on the Surface and stayed in the molten lead. **** happens!

[jsizemore]

I got a bunch of range scrap from an indoor range that had a metal backstop. When the copper jackets impact the steel backstop some of the jacket is pulverized and gets scooped up with the rest. It readily goes into the alloy when you smelt. If this is your lead source then it could be the problem.

[Grmps]

Fluxing with Sulfer will remove zinc but it will also remove tin. THIS WILL CREAT TOXIC FUMES

I wouldn't put anything in a casting pot/machine without smelting it at 700° and fluxing with both sawdust and wax

I've never found the need to cast over 720° except for using buckshot molds.

To clean my spouts I use a paneling nail with rings on it attached to the end of a piece of bamboo

a commercial caster using range scrap is interesting. Tha alloy content of range scrap is all over the place. do you XRF every batch of range scrap and alloy it to a given formula before you use it?

I haven't found zinc in range scraps BUT there are some people out there that cast boolits out of zinc

some people find that scraping the sides and bottom of a pot full of alloy with a piece of wood both loosens debris and works to flux the alloy

[Springfield]

I hand cast with a 40 lb Magma pot so I probably have the same orifices you have. On rare occasions the orifices will tend to plug up, have never found out why for sure. But I have found that doing a good fluxing/cleaning helps. I like to use sawdust and wax, and make sure I light it and the flame covers the whole top of the lead. Sometimes it is surprising what comes to the surface. It works better if the temp is around 720, higher than my normal 680 casting temp. If the dross on the top doesn't turn to ash then you need to do it again. I have never not been able to turn any slush on top back into the melt, you just have to be patient.

[fredj338]

My bet is some zinc in there. I have a magma master caster & only time it has ever frozen up is when a buddy gave me some ww alloy that had enough zinc in it to freeze up my pot. I had to crank the heat up & drain it. Oh yes, I NEVER empty the pot, ever. Fastest way to get crud into the orifice is empty it imo.

[Bird]

Drop the pot temperature to 600 degrees and wait for 5 mins. Anything unusual floating on the surface is likely to be zinc. Scrape it from the surface. If you top up the pot as the level goes down, the level of zinc contamination will increase. It seems that zinc will stay in the alloy at temps of over 600 deg, but will remain near the surface.
I had a similar problem with a lee pot. The flow got less and less as the pot got lower, and then added more of the same alloy. I ended up with wisps of lead hanging from the spout, and the bullets became difficult to drop from the molds. Alloy started to stick to the mold, as in hot dipped galvenizing.
I tested with acid, and got the fizz. Bullets were hard to size, but still looked perfect. I scraped alloy from the surface at 600 deg, and problems went away. There was also no sign of junk in the pot or cast bullets. I did not get all of the zinc out, but it no longer affected the castability.